op chem 2

Question 1

1.Percentage of carbon in steel ranges from- (A) 0.1 to 1.5 (B) 1.5 to 3.0 (C) 3.0 to 4.0 (D) 4.0 to 6.0

Answer 1

(A) [SSC Sec off. Exam, 2007] Exp: Steel contains around 98.9% of Iron and 0.1 to 1.5% of carbon. It is used for making blade, knife, utensils etc.

Question 2

2.The material used in electric heater is______ (A) Tungsten (B) Nichrome (C) Brass (D) Steel

Answer 2

(B) (SSC CGL 2016) Exp: The material used in electric heater is Nichrome. Nichrome is a mixture of Nickel, Chromium and Iron.

Question 3

3.Fuse wire is made of an alloy of (A) Tin and Lead (B) Tin and Copper (C) Lead and Copper (D) Copper and Silver

Answer 3

(A) (SSC CGL 2016) Exp: Fuse wire is made of alloy of Tin (Sn) and Lead (Pb). It is a piece of wire with a low melting point.

Question 4

4.Type of metals used in Printing, is an alloy of- (A) Lead and Copper (B) Lead and Antimony (C) Lead and Bismuth (D) Lead and Zinc

Answer 4

(B) [SSC CPO 2006] Exp: Type of Metal Used in Printing is an alloy of Lead, tin and Antimony and their quantity in% given as follows. Lead = 60-86%, Antimony = 11-30%, Tin = 3-20%

Question 5

5.An alloy used in making heating elements for electric heating devices is - (A) Solder (B) Alloy steel (C) Nichrome (D) German Silver

Answer 5

(C) [SSC CHSL 2013] Exp: Heating effect of electric current is used in the appliances such as Electric Heater, Electric Iron, Room Heater etc. These Heating devices are operated by coils of very high resistance, which are made up of alloy Nichrome. Nichrome is an alloy of Nickel, Chromium and Iron.

Question 6

6.Shock absorbers are usually made up of steel as it? (A) Is not brittle (B) Has lower elasticity (C) Has Higher elasticity (D) Has no Higher elasticity

Answer 6

(C)Exp: Shock absorbers are usually made of steel because steel has higher elasticity. Elasticity is the ability of an object to resume its normal shape after being stretched or compressed.

Question 7

7.Which one of the following Metals is used to Heat up the electric iron? (A) Copper (B) Tungsten (C) Nichrome (D) Tin

Answer 7

(C) [SSC MTS 2011] Exp: Electric iron contains high resistance metal Nichrome as a heating element, stripped insulated by Mica. It does not melt even at very high temperature.

Question 8

8.Wh ich of the fol lowing is the purest commercial form of Iron? (A) Pig Iron (B) Steel (C) Stainless Steel (D) Wrought Iron

Answer 8

(D) [SSC CGL Exam, 2014] Exp: Wrought Iron is the purest commercial form of Iron. It is the purest ore of iron containing carbon around 0.04 to 0.08%, which is less than even in the steel.

Question 9

9.Which of the following is purest form of Iron? (A) Steel (B) Cast Iron (C) Wrought Iron (D) Pig iron

Answer 9

(C) [SSC CGL 2005, SSC FCI 2012] Exp: Wrought Iron is the purest commercial form of Iron. It is the purest ore of iron containing carbon around 0.04 to 0.08%, which is less than even in the steel.

Question 10

10.The Percentage of carbon in cast iron is - (A) 3 to 5 (B) 0.1 to 0.25 (C) 0.5 to 1.5 (D) 6 to 8

Answer 10

(A) [SSC CGL Exam, 2014] Exp: Depending upon the% of carbon Iron is of three types. Cast iron, pig iron and Steel. Amount of (%) carbon present in Cast iron, Pig Iron and Steel is 2 to 4%, 0.1 to 0.25% and 0.5 to 1.5 respectively.

Question 11

11.The Iron ore which contains 72% of Iron is - (A) Magnetite (B) Limonite (C) Haematite (D) Siderite

Answer 11

(A) [SSC FCI 2012] Exp: Percentage of Iron in different iron ores are given as:- 1. Magnetite (Fe3O4) - 72% 2. Haematite (Fe2O3) - 70% 3. Limonite (Fe2O3+H2O) - 55 - 66% 4. Siderite (FeCO3) - 48%

Question 12

12.Stainless Steel is an alloy of - (A) Chromium and Carbon (B) Chromium and iron (C) Chromium, carbon and iron (D) Chromium and iron

Answer 12

(C) [SSC FCI 2012] Exp: Stainless steel is an alloy of Chromium, Iron and Carbon.

Question 13

13.Hard Steel contains - (A) 2 to 5% of carbon (B) 0.5 to 1.5% of carbon (C) 0.1 to 0.4% of carbon (D) 0.01 to 0.04% of carbon

Answer 13

(B) [SSC CGL 2011] Exp: Steel containing carbon 0.1 to 0.4% is known as Mild steel while steel having carbon 0.5 to 1.5% is called Hard steel.

Question 14

14.The manufacturing of iron from iron-ore involves the process of (A) Oxidation (B) Reduction (C) Electrolysis (D) Fractional distillation

Answer 14

(B) (SSC CGL 2016) Exp: Haematite (Fe2O3) is main ore of iron metal. It is an Oxide Ore. Reduction process is used in manufacturing of iron because oxides are reduced.

Question 15

15.The use of Heat treatment of ore that includes smelting and roasting is termed as- (A) Cry metallurgy (B) Pyrometallurgy (C) Electrometallurgy (D) Hydrometallurgy

Answer 15

(B) [SSC CHSL 2015] Exp: Pyrometallurgy is the branch of science and technology concerned with the use of the High temperature to extract and purify metals. It consists of the thermal treatment of minerals and metallurgical ore (calcinations, Roasting, Refining and Smelting). Fe, Cu, Zn, Cr, Tin etc. are extracted by this process.

Question 16

16.Heating of ore in the absence of air below its melting point is called- (A) Leaching (B) Roasting (C) Smelting (D) Calcination

Answer 16

(D) [SSC CHSL 2013] Exp: In Calcination process Carbonate, Hydroxide or Oxide ores are heated frequently in the absence of air.

Question 17

17.Froth Floatation process is used for the metallurgy of - (A) Sulphide ore (B) Oxide ore (C) Sulphate ore (D) Chloride ore

Answer 17

(A) Exp: Froth floatation method has been used for the concentration of sulphide ores such as Galena (PbS), Copper pyrites are preferentially wetted by palm oil and gangue particle by water.

Question 18

18.Aluminium can be purified by- (A) Oxidation (B) Electrolysis (C) Ozonolysis (D) Distillation

Answer 18

(B) [SSC CPO 2006] Exp: The aluminium metal obtained by the electrolysis of alumina is 99% pure.

Question 19

19.Ultra purification of a metal is done by- (A) Slugging (B) Leaching (C) Zone Melting (D) Smelting

Answer 19

(C)Exp: Ultra purification of metal is done by Zone Melting Method.

Question 20

20.Which material is used in the manufacturing of electric heater coil? (A) Copper (B) Iron (C) Nickel (D) Nichrome

Answer 20

(D) (SSC CPO 2017) Exp: Nichrome is an alloy of Nickel (Ni), Chromium (Cr) & Iron (Fe). It is used in the manufacturing of electric heater coil because of its high resistance.

Question 21

21.Which of the following cloth will readily catch fire? (A) Cotton cloth (B) Polyester cloth (C) Acrylic cloth (D) Nylon cloth

Answer 21

(A) (SSC CPO 2017) Exp: Cotton cloth catches fire easily because of its light texture.

Question 22

22.Which of the following are the main components of stainless steel? (A) Iron and carbon (B) Silver (C) Iron, chromium and nickel (D) Iron and nickel

Answer 22

(C) (SSC CPO 2017) Exp: Stainless steel is an alloy of Iron, chromium & nickel. It is corrosion resistant.

Question 23

23.Which of the following pairs is Incorrect? I. Haematite: Iron II. Pitchblende: Copper III. Monazite: Thorium (A) Only I (B) Only II (C) Only I and II (D) Only I and III

Answer 23

(B) (SSC CGL 2017) Exp: Ore Metal Haematite Iron Pitchblende Uranium Monazite Thorium

Question 24

24.Which of the following is an ore of Aluminium? (A) Galena (B) Cryolite (C) Cinnabar (D) Epsom salt

Answer 24

(B) (SSC CGL 2017) Exp: Galena (PbS) = lead ore Cryolite (Na3AlF6) = Aluminium ore Cinnabar (HgS) = Mercury ore Epsom salt (MgSO4.7H2O) = Salt of Magnesium

Question 25

25.What are the main components of Brass alloy? (A) Copper and Zinc (B) Copper and Strontium (C) Copper, Zinc and Nickel (D) Copper and Nickel

Answer 25

(A) (SSC CGL 2017) Exp: Brass is an alloy of Copper & Zinc. Cu = 60% & Zn = 40%. It is used for making plumbing & electric appliances.

Question 26

26.Which of the following is an ore of iron? (A) Dolomite (B) Epsom salt (C) Siderite (D) Galena

Answer 26

(C) (SSC CGL 2017) Exp: Siderite (FeCO3) = Ore of Iron Galena (PbS) = Ore of lead Dolomite (CaCO3.MgCO3) = Ore of Magnesium & Calcium Epsom salt (MgSO4.7H2O) = Salt of Magnesium

Question 27

27.What are the main components of Bronze alloy? (A) Copper and Zinc (B) Copper and Tin (C) Zinc and Nickel (D) Aluminium and Nickel

Answer 27

(B) (SSC CGL 2017) Exp: Bronze is an alloy of copper & tin. It consists 88% of copper & 12% of tin. It is used for manufacturing the doors, windows, sculptures & utensils.

Question 28

28.________ is made by mixing iron with carbon and metals like chromium, nickel and manganese. (A) Ship (B) Stainless steel (C) Rust (D) Ozone

Answer 28

(B) (SSC CGL 2017) Exp: Stainless steel is made by mixing iron with carbon & metals like chromium, nickel & manganese. It is a corrosion resistant alloy which is used for making utensils

Question 29

1.Identify the metal which is Non-toxic in nature- (A) Gold (B) Cadmium (C) Cobalt (D) Chromium

Answer 29

(A) [SSC CHSL 2010] Exp: In the given metals, Gold is nontoxic in nature while cadmium, cobalt and chromium are toxic.

Question 30

2.Main constituent of liquid bleach is - (A) Hydrochloric acid (B) Sodium chloride (C) Sodium hypochlorate (D) Sodium hypochlorite

Answer 30

(D) [SSC CHSL Exam, 2015] Exp: Sodium hypochlorite (NaOCl) when dissolved in water is commonly known as bleach or liquid bleach. It is used as disinfectant or a bleaching agent.

Question 31

3.Caustic Soda is - (A) Deliquescent (B) Oxidant (C) Reductant (D) Efflorescent

Answer 31

(A) [SSC CHSL 2012] Exp: Caustic soda is chemically known as sodium hydroxide (NaOH). It is deliquescent. Deliquescene: The property of certain compounds of taking up the moisture present in atmosphere and becoming wet when exposed is knwon as deliquescene. These compounds are known as deliquescent. eg. KOH, anhy.CaCl2, anhy. MgCl2, anhy.FeCl3.

Question 32

4.Which of the following is used in welding broken pieces of iron rails and parts of machine- (A) Aluminium sulphate (B) Solder (C) Aluminium powder (D) None of these

Answer 32

(C) [SSC FCI 2012] Exp: Aluminium Powder is used in welding broken pieces of iron rail and machine parts.

Question 33

5.Hydrogen sulphide is a- (A) Colourless, odourless gas (B) Yellowish gas with pungent odour (C) Reddish brown gas with fishy odour (D) Colourless gas with rotten egg smell

Answer 33

(D) [SSC Steno 2014] Exp: Hydrogen Sulphide is a colourless gas with rotten egg smell.

Question 34

6.Tip of match stick contains - (A) Phosphorous penta oxide (B) White phosphorous (C) Red phosphorous (D) Phosphorous trichloride

Answer 34

(C) [SSC Tax Asst. 2009, FCI 2012] or Head of safety Matches contains - (A) P2O3 (B) Sb2S3 (C) Yellow Phosphorous (D) Red Phosphorous (D) [SSC MTS 2014] Exp: Tip of match stick contains red phosphorous.

Question 35

7.Match Stick uses the allotrope of Phosphorous- (A) Any Phosphorous (B) Red phosphorous (C) Black Phosphorous (D) Purple Phosphorous

Answer 35

(B) [SSC CGL 2002] Exp: Tip of match stick contains red phosphorous. Red phosphorous is an allotrope of phosphorous.

Question 36

8.Most abundant inert gas in the atmosphere is (A) He (B) Ne (C) Kr (D) Ar

Answer 36

(D) [SSC CGL 2014] Exp: Most abundant inert gas in the atmosphere is Argon. Total percentage of noble gases in dry air is about 1% by volume, of which Argon (0.93%) is the major component.

Question 37

9.Green colour seen in firework display, is due to the chloride salt of- (A) Sodium (B) Calcium (C) Barium (D) Strontium

Answer 37

(C) [SSC CGL Exam, 2015] Exp: In fireworks, Green colour is displayed due to chloride salts of Barium. Salts used for different colours are:- Salt Colour 1. Strontium sulphate - Red 2. Strontium Carbonate - Bright Red Colour 3. Sodium Salt - Golden yellow 4. Copper Salt - Blue 5. Aluminium Powder - Silver Colour.

Question 38

10.Which of the following will displace Hydrogen from acids to form salts? (A) S (B) Na (C) Ag (D) P

Answer 38

(B) [SSC CHSL 2014] Exp: For the Formation of salts, sodium will displace Hydrogen because in electrochemical series Hydrogen is below sodium. 2HCl + 2Na 2NaCl + H2

Question 39

11.Liquid Chemical used for artificial rain or cloud seeding- (A) Silver iodide (AgI) (B) Sodium chloride (NaCl) (C) Dry ice (solid CO2) (D) All the these

Answer 39

(D)Exp: Silver iodide, sodium chloride and dry ice are oftenly used fluid chemical for artificial rain or cloud seeding.

Question 40

12.The inert gas used as beacon Light is - (A) Krypton (B) Argon (C) Helium (D) Neon

Answer 40

(D) [SSC CHSL 2014] Exp: Neon (noble gas) is used in beacon light as safety signal for air navigators because its light has fog penetrating power.

Question 41

13.Hydrogen was discovered by - (A) Boyle (B) Charles (C) Cavendish (D) Priestley

Answer 41

(C) [SSC CGL 2014] Exp: Hydrogen was discovered by Henry Cavendish in 1766. Hydrogen is the lightest gas. It is known as fuel of future.

Question 42

14.Gas used in the production of vegetable ghee is- (A) Hydrogen (B) Helium (C) Oxygen (D) Nitrogen

Answer 42

(A) [SSC FCI 2012] Exp: Hydrogen Gas is used in the production of vegetable ghee. This process is known as Hydrogenation.

Question 43

15.Ozone Contains- (A) Only oxygen (B) Oxygen and nitrogen (C) Hydrogen and carbon (D) Oxygen and carbon

Answer 43

(A) [SSC CPO 2009] Exp: Chemical formula of ozone is O3, so ozone contains only oxygen. Ozone is a pale blue gas.

Question 44

16.Ozone is represented as _____. (A) O3 (B) H2O2 (C) Cl2O (D) N2O

Answer 44

(A) (SSC CHSL 2016) Exp: Chemical formula of ozone is O3, so ozone contains only oxygen. Ozone is a pale blue gas.

Question 45

17.A white solid ‘A’ gives off a gas which turns lime water milky. The residue is yellow but turns white on cooling. Now the solid is- (A) Zinc sulphate (B) Zinc carbonate (C) Lead sulphate (D) Lead carbonate

Answer 45

(B) (SSC CHSL 2012) Exp: Carbon dioxide turns lime water into calcium carbonate. ZnCO 3 ZnO+CO2 (Milky Appearance) yellow ZnO(white) Zinc Carbonate Cooling Ca(OH) + CO 2 2 CaCO + H O 3

Question 46

18.Which of the following can not be formed (A) He+2 (B) He+ (C) He (D) He2

Answer 46

(D) Exp: Noble gases are monoatomic so formation of He2 is not possible.

Question 47

19.Chemical name of bleaching powder is- (A) Calcium chlorate (B) Calcium hypochlorite (C) Calcium chloro hypochlorite (D) Calcium dichloride

Answer 47

(B) [SSC CGL 2006, SSC CHSL 2010] Exp: Chemically Bleaching powder is known as calcium hypochlorite and its chemical formula is CaOCl2. It is used in disinfection of water and as a bleaching agent. It is also used for the manufacturing of chlorine gases and chloroform (CHCl3)

Question 48

20.Which one among the following is used commonly in the dehydration of water? (A) Bleaching powder (B) Alum (C) Borax (D) Soda powder

Answer 48

(A) Exp: Calcium hypochlorite (bleaching powder) is an inorganic compound with formula CaOCl2. It is used as dehydrating agent along with CaCl2.

Question 49

21.Which one of the following is odd- (A) Chalk (B) Slaked lime (C) Limestone (D) Marble

Answer 49

(B) [SSC CHSL 2011] Exp: Marble is a metamorphic rock, which is the result of metamorphosis of Lime stone. Chalk is also a type of Lime Stone. Slaked Lime is a colourless crystal with chemical formula Ca(OH)2.

Question 50

22.Lime water becomes milky when exposed to air due to the presence of - (A) Carbon dioxide (B) Nitrogen (C) Oxygen (D) Sulphur dioxide

Answer 50

(A) [SSC CHSL 2011] Exp: Lime water becomes milky when exposed to air due to the presence of carbondioxide. Ca(OH)2 + CO2 CaCO3+ H2O

Question 51

23.Which of the following gas is coloured? (A) Oxygen (B) Nitrogen (C) Chlorine (D) Hydrogen

Answer 51

(C) (SSC CHSL 2015) Exp: Oxygen, Nitrogen and Hydrogen are colourless gases while chlorine is a greenish yellow coloured gas.

Question 52

24.Chemically Lime water is - (A) Calcium Hydroxide (B) Sodium Carbonate (C) Sodium Hydroxide (D) Calcium carbonate

Answer 52

(A) (SSC CGL 2006) Exp: Chemically Lime water is known as calcium Hydroxide and its chemical formula is Ca(OH)2.

Question 53

25.Which gas is used as a fire extinguisher? (A) Carbon dioxide (B) Carbon monoxide(C) Carbon suboxide (D) Sulphur dioxide

Answer 53

(A) (SSC Tax Asst. 2007) or Gas is used as a fire extinguisher is- (A) Neon (B) Nitrogen (C) Carbon dioxide (D) Carbon monoxide (C) (SSC CHSL 2013) Exp: Carbon dioxide Gas is used as a fire extinguisher. It stops the supply of oxygen which is necessary for the burning of object because CO2 is heavier than oxygen.

Question 54

26.Mercury is a - (A) Solid metal (B) Liquid metal (C) Solid nonmetal (D) Liquid nonmetal

Answer 54

(B) (SSC Steno 2010) Exp: Mercury is liquid Metal, it is an essential constituent of Ama lgams. It is found is liquid state at room temperature.

Question 55

27.What is dry ice? (A) Dry ice without water (B) Benzoic acid (C) Glacial acetic acid (D) Solid carbon dioxide

Answer 55

(D) [SSC MTS 2008, SSC CGL 2012] Or

Question 56

Dry ice is a solid type of- (A) Air (B) Nitrogen (C) Water (D) Carbon dioxide

Answer 56

(D) (SSC MTS 2011, SSC CGL 2015) Exp: Dry ice is solid carbon dioxide (CO2) with a low temperature of -78° C (-109° F). At atmospheric pressure, solid CO2 sublimates directly to vapour without a liquid phase.

Question 57

28.Diamond does not conduct electricity, because (A) It’s structure is very compact (B) It is of crystalline nature (C) There are only carbon atoms, present in it (D) No free electrons are present in it

Answer 57

(D) (SSC CGL 2016) Exp: Since all the electrons are firmly held in C-C - bonds, there are no free electrons in a diamond crystal. Therefore, diamond is a bad conductor of electricity.

Question 58

29.Charcoal is used in water treatment as a/an- (A) Solvent (B) Absorbent (C) Coagulant (D) Adsorbent

Answer 58

(D) [SSC CHSL 2012] Exp: Charcoal or coal of wood is a black Brownish Product which is formed when wood or bone is combusted in the absence of oxygen and water. Volatile constituents from animals and vegetation are removed. Charcoal is used as an adsorbent in water treatment because charcoal adsorbs the pollutants present in water.

Question 59

30.The gas which turns into Liquid at the Lowest temperature among the following is- (A) Hydrogen (B) Oxygen (C) Helium (D) Nitrogen

Answer 59

(A) [SSC CGL 2008] Exp: At the lowest temperature Hydrogen turns into Liquid.

Question 60

31.Heavy water means- (A) Water which is used in heavy industries. (B) Distilled water (C) Water containing Maximum density (D) Water containing salts of calcium and Magnesium

Answer 60

(C) [SSC CPO 2009] Exp: Heavy water means water containing maximum density. It contains Deuterium, an isotope of Hydrogen. It contains 11% more density than simple water but physically and chemically is same as simple water. It is used as a moderator in nuclear reactors.

Question 61

32.What is the chemical composition of Heavy Water? (A) H2 O (B) HDO (C) D2 O (D) H2O2

Answer 61

(C) [SSC GD 2015] Exp: Heavy water is chemically deuterium oxide (D2O). Heavy water contains heavy hydrogen or deuterium.

Question 62

33.Soda water contains - (A) SO2 (B) NO2 (C) H2 (D) CO2

Answer 62

(D) [SSC CGL 2014] Exp: Soda water contains Carbon dioxide (CO2) gas.

Question 63

34. Which of the following is used for making smoke bombs? (A) Sulphur (B) Phosphorous (C) Hydrogen (D) Carbon

Answer 63

(B) [SSC CGL 2005] Exp: Phosphorous is used for making the smoke bombs. It is also used in making match box, crackers and explosive materials.

Question 64

34.Hydrogen Peroxide is an effective Sterilizing agent. Which one of the following product is formed when it readily loses active oxygen? (A) Water (B) Hydrogen (C) Ozone (D) Nascent hydrogen

Answer 64

(A) Exp: Hydrogen peroxide is an effective sterilizing agent, when active oxygen disappears from it, then it forms water. 2H2O2 2H2O + O2

Question 65

35.In deep see diving, divers use a mixture of gases consisting of oxygen and- (A) Argon (Ar) (B) Helium (He) (C) Helium (He) and nitrogen (N) (D) Hydrogen (H)

Answer 65

(C) [SSC MTS 2014] Exp: In deep sea water, divers used a mixture of oxygen, Nitrogen and Helium which is known as Trimix.

Question 66

36.The Gas dissolved in water that makes it basic is? (A) Hydrogen (B) Carbon dioxide (C) Sulphur dioxide (D) Ammonia

Answer 66

(D) [SSC CHSL 2015] Exp: Dissolved ammonia (NH3) in water makes it basic. Polar characteristics of ammonia and its tendency to form bonding shows its High Solubility in water. In aqueous Solution Ammonia act as a base and form Hydroxyl and Ammonium ion. NH3 + H2O NH4 + OH-

Question 67

37.Which metal is extracted from Sea water? (A) Potassium (B) Aluminium (C) Magnesium (D) Beryllium

Answer 67

(C) [SSC Sec. Officer 2007] Exp: Magnesium is extracted from sea salts MgCl2.6H2

Question 68

39. Silicone is a Polymer of- (A) Silicon Tetra Chloride (B) Dialkyl dichloro silane (C) Silane (D) Tetra alkyl silane

Answer 68

(B) [SSC CGL 2013] Exp: Silicon is a polymer of dialkyl dichloro silane (R2SiCl2). Silicones: These are organosilicon polymeric compounds containing Si-O-Si linkages. These have general formula of (R2SiO)n having (R2SiO-) as a repeating unit. (R may be alkyl or phenyl group). The starting material for the manufacturing of silicones is alkyl or aryl substituted chlorosilanes.

Question 69

0.Which one of the following gases mixed oxygen in aqualungs used by divers for the breathing? (A) Methane (B) Nitrogen (C) Helium (D) Hydrogen

Answer 69

(C) [SSC MTS 2002, SSC CHSL 2011] Exp: Helium-oxygen mixture is used by deep sea divers in preference to nitrogen oxygen mixture because of its very low solubility in blood. It is also used to assist breathing in asthma.

Question 70

1.Which of the oxide is neutral? (A) CO (B) SnO2 (C) ZnO (D) SiO2

Answer 70

(A) Exp: CO is a neutral oxide. Neutral oxides show neither basic nor acidic properties and hence do not form salt when reacted with acids or bases. eq. NO, N2O etc

Question 71

2.Which of the following oxide is amphoteric in character? (A) CaO (B) CO2 (C) SiO2 (D) SnO2

Answer 71

(D) Exp: Metal oxide which show both acidic as well as basic behaviour are known as amphoteric oxide. These oxides react with acids as well as base to produce salt and water. eg: ZnO, SnO2, PbO2, Al2O3 etc

Question 72

3.Which one of the following is a biochemical sediment rock? (A) Marble (B) Coal (C) Granite (D) Slate

Answer 72

(B) [SSC MTS 2006] Exp: Sedimentary rocks are important sources of natural resources like coal, fossil fuels or ores. Depending upon the quantity of carbon% coal are of four type- 1. Peat coal Carbon content is 50 - 60%. It is lowest grade of coal. 2. Lignite coal Carbon content is 65 - 70%. It is known as brown coal 3. Bituminous coal Carbon content is 70-85%. It is also known as soft coal. 4. Anthracite coal Carbon content is 90% - 95%. It is the best grade of coal.

Question 73

4.Which one of the following element is an Example of noble gas? (A) Nitrogen (B) Hydrogen (C) Chlorine (D) Helium

Answer 73

(D) [SSC CHSL Exam, 2014] Exp: In the given elements, Helium is an example of noble gas. Noble gases have completely filled orbitals (stable configuration). Helium, Neon, Argon, Krypton, Xenon and Radon are Noble gases.

Question 74

5.Which one of the following is not a form of carbon? (A) Graphite (B) Charcoal (C) Soot (D) Haematite

Answer 74

(D) Exp: Haematite (Fe2O3) is not a form of carbon. It is an ore of Iron.

Question 75

6.Percentage of Lead in Lead Pencils is - (A) 0 (B) 31-66 (C) 40 (D) 80

Answer 75

(A) [SSC Sec off. 2007] Exp: In Lead pencils, Lead is 0%. In lead pencils, graphite is used.

Question 76

7.The material used in the manufacture of Lead pencil is- (A) Graphite (B) Lead (C) Carbon (D) Mica

Answer 76

(A) [SSC CGL MST 2010, SSC Steno 2005, 2002] Exp: Graphite is used in pencils because of its ability to leave grey marks on paper. It is crystalline allotrope of carbon. Note: In lead pencils lead percentage is 0

Question 77

8.P laster of Paris is made by the Partial dehydration of- (A) Green vitriol (B) Blue vitriol (C) Gypsum salt (D) Epsom salt

Answer 77

(C) [SSC MTS 1966, SSC Tax Asst. 2006] Exp: Plaster of Paris is formed by the partial dehydration of Gypsum Salt. It is used in the medicals for plastering the bones, in making toys and statues etc. CaSO4. 2H2O 373 K (CaSO4). 1 2 H2O + 3 2 H2O (Gypsum) (POP)

Question 78

9.Which among the following halogens is the most reactive? (A) Fluorine (B) Bromine (C) Iodine (D) Chlorine

Answer 78

(A) [SSC CHSL Exam, 2010] Exp: Fluorine is the most reactive among the Halogens. Fluorine has the lowest bond dissociation enthalpy. This is due to weak F-F bond because of the repulsion between the non-bonding electrons in the small molecule.

Question 79

10.Non-metal found in Liquid State- (A) Bromine (B) Nitrogen (C) Fluorine (D) Chlorine

Answer 79

(A) [SSC CHSL Exam, 2013] Exp: Bromine is the only nonmetal which is found in liquid State at room temperature. It has reddish brown colour.

Question 80

11.Which silver salt is used for making film of photography? (A) Silver bromide (B) Silver chloride (C) Silver sulphate (D) Silver nitrate

Answer 80

(A) [SSC MTS 2002, SSC Sec off. 2006] Exp: Silver Bromide is used to prepare the Light sensitive chemical (Emulsion) over photographic film, because these are soluble in Hypo solution (Sodium thiosulphate) which makes photographic film transparent.

Question 81

12.The chemical name of Hypo commonly used in Photography is- (A) Sodium thiosulphate(B) Sodium nitrate (C) Sodium chloride (D) Silver nitrate

Answer 81

(A) [SSC CHSL 2014] Exp: The chemical name of Hypo commonly used in photography is sodium thiosulphate (Na2S2O3).

Question 82

13.Silver halides are used in photographic plate because they are- (A) Oxidised in air (B) Soluble in Hyposolution (C) Reduced by Light (D) Totally coloureless

Answer 82

(C) [SSC CGL 2010] Exp: Silver halides are used in photographic plates because they are Reduced by Light.

Question 83

14.Chemically ‘Philosopher Wool’ is a- (A) Zinc oxide (B) Calcium oxide (C) Aluminium oxide (D) Magnesium

Answer 83

(A) [SSC CHSL Exam, 2012] Exp: Chemically Philosopher Wool is a zinc oxide (ZnO). It is also known as zinc white. It is a constituent of cigarette filters. It can be used in lotions and creams to protect skin from UV light.

Question 84

15.Oxygen is a- (A) Reducing agent (B) Combustion nourishing (C) Constituent of all gas (D) Inflammable gas

Answer 84

(B) [SSC Steno 2014] Exp: Oxygen is a combustion nourishing gas. It is a supporter of combustion.

Question 85

16.Carbon monoxide is an inflammable gas which one of the following is also inflammable? (A) Helium (B) Nitrogen (C) Oxygen (D) Hydrogen

Answer 85

(D) [SSC CPO 2009] Exp: Carbon monoxide (CO) is an inflammable gas. Hydrogen is also an inflammable from the given options and oxygen is combustion supporting gas.

Question 86

17.Select the incorrect statement regarding the carbon compounds - (A) They have low melting and boiling Point (B) Insoluble in water (C) These are not easily combustible (D) They mainly contain carbon and Hydrogen.

Answer 86

(C) [SSC MTS 2013] Exp: Carbon compounds are easily combustible in the presence of air and their melting point and boiling point are low. They are water insoluble and mainly consists of carbon & hydrogen.

Question 87

18.Chemical Name of common salt is- (A) Sodium chloride (B) Sodium nitrate (C) Ammonium chloride(D) Calcium chloride

Answer 87

(A) [SSC Sec officer 2007] Exp: Chemical name of common salt is sodium chloride and it’s also known as Rock Salt. Its chemical formula is NaCl.

Question 88

19.Sodium chloride or Table salt occurs in nature as the mineral: (A) Sylvite (B) Talc (C) Halite (D) Sphalerite

Answer 88

(C) [SSC CHSL Exam, 2015] Exp: Sodium chloride or Table salt occurs in nature as the mineral Halite.

Question 89

20.Sodium carbonate commonly known as- (A) Baking soda (B) Washing soda (C) Caustic soda (D) Caustic potash

Answer 89

(B)Exp: Sodium carbonate is commonly known as washing soda. It is manufactured by solvay-ammonia process. It is white crystalline solid which crystallizes as decahydrate (Na2CO3.10H2O).

Question 90

21.Chemical formula of washing soda is- (A) Na2SO4.10H2O (B) NaHCO3 (C) Na2CO3.10H2O (D) Ca(OH)2

Answer 90

(C) [SSC CHSL Exam, 2014] Exp: Chemical formula of washing soda is Na2CO3.10H2O.

Question 91

22.The common name of sodium bicarbonate is _____. (A) Baking soda (B) Borax (C) Bleach (D) Epsom salt

Answer 91

(A) (SSC CHSL 2016) or Commercial name of sodium bicarbonate is - (A) Washing Soda (B) Baking Soda (C) Bleaching Powder (D) Soda Ash (B) [SSC MTS 2010, SSC Tax Asst. 2009] Exp: Commercial name of Sodium bicarbonate (NaHCO3) is Baking soda because on heating it decomposes to evolve bubbles of CO2 (leaving holes in cakes or pastries to make them light & fluffy).

Question 92

23.Chemical name of baking soda is- (A) Sodium carbonate (B) Sodium bicarbonate (C) Sodium chloride (D) Sodium nitrate

Answer 92

(B) [SSC CHSL 2014] Exp: Chemical name of baking soda is Sodium bicarbonate (NaHCO3).

Question 93

24.What is baking soda? (A) Aluminium bicarbonat (B) Sodium isolate (C) Sodium bicarbonate (D) Aluminium sulphate

Answer 93

(C) (SSC CHSL 2016) Exp: Sodium bicarbonate (NaHCO3) is known as baking soda. It is used in fire extinguisher for generating CO2.

Question 94

25.Mortar is a mixture of water, sand - (A) Slaked lime (B) Quick Lime (C) Lime Stone (D) Gypsum

Answer 94

(A) [SSC Tax Asst. 2009] Exp: Slaked lime is used as building material in the form of mortar. It is prepared by mixing slaked lime with 3-4 times its weight of sand. The mixture is made into a thick paste with gradual addition of water. This paste is called mortar.

Question 95

26.Most commonly bleaching agent is - (A) Carbon dioxide (B) Alcohol (C) Chlorine (D) Sodium Chloride

Answer 95

(C) [SSC CGL 2015] Exp: Most commonly bleaching agent is chlorine (Cl2). It bleaches only in presence of water. Since chlorine bleaches by oxidation, the bleaching action of chlorine is permanent. Chlorine produces HCl during bleaching therefore it is used only for paper pulp, wood pulp and cloth.

Question 96

27.Helium gas is filled in the balloon instead of Hydrogen because its- (A) Lighter than Hydrogen (B) More abundant than Hydrogen (C) Non-Combustible (D) More stable

Answer 96

(C) [SSC CGL Exam, 2008] Exp: Because it is a noncombustible (non-flammable) gas.

Question 97

28.Why Helium gas used in balloons? (A) Its atomic number is two (B) Its Lighter than air (C) It’s one of the constituents of water (D) It’s a noble gas

Answer 97

(B) [SSC MTS Exam 1999] Exp: Helium gas is lighter than air and non-flammable (noncombustible) so it is used in balloons.

Question 98

29.A balloon filled with Helium rises in air because- (A) Air exerts on upward force on the balloon. (B) The balloon is weightless (C) Helium is less dense than air (D) Helium pushes down the air below the balloon.

Answer 98

(C) [SSC CPO Exam, 2011] Exp: Because helium is less dense than air.

Question 99

30.Which gas is filled in balloons? (A) Hydrogen (B) Helium (C) Carbon dioxide (D) Oxygen

Answer 99

(B) [SSC Steno Exam, 2014] Exp: Helium gas is used in balloons, because it’s lighter than air. Earlier it was used in tyres but now a days Nitrogen is filled in Aeroplane tyers.

Question 100

31.Which of the following Noble gas can forms compound? (A) Helium (B) Argon (C) Xenon (D) Krypton

Answer 100

(C) [SSC CHSL 2010, SSC Steno 2011] Exp: Xenon is a noble gas (Chemical element) with symbol Xe and atomic number 54. Due to Low Ionization Potential it can react with fluorine and oxygen in special conditions and forms chemical compounds. Such as XeF2, XeF4, XeOF4 etc.

Question 101

32.The maximum density of water is at- (A) 1000C (B) 00C (C) 40C (D) 2730C

Answer 101

(C) [SSC CHSL Exam, 2014] Exp: The maximum density of water is at 40C. Above this temperature, its density decreases because its volume increases. Below this temp its density also decreases.

Question 102

33.White Phosphorous is placed under the- (A) Ammonia (B) Cold water (C) Alcohol (D) Kerosene

Answer 102

(B)Exp: White Phosphorous is insoluble in water but soluble in benzene, carbon disulphide liquid NH3. It is stored under water to protect it from air. Its ignition temperature is very low and therefore, it catches fire in the air to form white dense fume.

Question 103

34.Commonly sodium is kept under the- (A) Alcohol (B) Water (C) Ammonia (D) Kerosene oil

Answer 103

(D) [SSC Stenographer 2005] Exp: Alkali metals (Li, Na, K etc) are placed under the kerosene oil because they can be easily oxidised with air and water due to their high reactivity.

Question 104

35.Which of the following can be used as an anesthetic? (A) NH3 (B) NO (C) NO2 (D) N2O

Answer 104

(D) [SSC MTS 2014] Exp: Nitrous oxide (N2O) is commonly known as laughing gas or happy gas. It can be used as an anesthetic in surgery and dental treatment.

Question 105

36.Dry powder fire extinguisher contains - (A) Sand (B) Sand and sodium carbonate (C) Sand and potassium carbonate (D) Sand and sodium bicarbonate

Answer 105

(D) [SSC CPO 2010] Exp: Normally Sand and sodium bicarbonate is used in dry Powder fire extinguisher.

Question 106

37.No. of unpaired electron in inert gas is (A) zero (B) 8 (C) 4 (D) 18

Answer 106

(A) Exp: All electrons are paired in noble gases (inert gases) so no. of unpaired electrons in noble gases is zero.

Question 107

38.Noble gas used in the treatment of cancer is- (A) Helium (B) Argon (C) Krypton (D) Radon

Answer 107

(D) [SSC CGL 2011] Exp: Radon gas is used in treatment of cancer. It is radioactive in nature. It is the only noble gas that is not present in atmosphere. It is the heaviest gas at room temperature. It is obtained as a decay product of 88Ra226. 222 226 4 86 88 2 Ra Rn He

Question 108

39.Old oil painting becomes black due to the formation of- (A) Cu2S (B) PbS (C) CaS (D) Na2S

Answer 108

(B) Exp: Old oil painting becomes black due to formation of lead sulphide (PbS). When H2S gas (present in air) react with lead (present in lead paint) formation of lead sulphide takes place.

Question 109

40.Which of the follow ing is second most abundant element on the surface of sun beside Hydrogen? (A) Helium (B) Neon (C) Argon (D) Oxygen

Answer 109

(A) Exp: After Hydrogen, Helium is the Second most abundant element on the surface of sun. Helium - 24.85% Iron - 0.16% Carbon - 0.29% Neon - 0.12%

Question 110

41.What is Asbestos? (A) Calcium magnesium silicate (B) Alumina (C) Calcium silicate (D) Magnesium silicate

Answer 110

(A) [SSC Steno Exam, 2005] Exp: Asbestos contains silicates of metals such as calcium magnesium, nickel, iron and manganese etc.

Question 111

42.At room temperature, the metal that remains liquid is: (A) Mercury (B) Platinum (C) Lead (D) Zinc

Answer 111

(A) (SSC CGL 2016) Exp: Mercury metal has melting point of -37.9ºF. This is due to weak metallic bonding as mercury has fulfilled valence orbitals. Melting point is the temperature at which a substance changes from solid to liquid state.

Question 112

43.If the bullets could not be removed from gunshot injury of a man, it May cause poisoning by- (A) Mercury (B) Lead (C) Iron (D) Arsenic

Answer 112

(B) [SSC CGL Exam, 2010] Exp: If the bullets could not be removed from gunshot injury of a man, it causes poisoning in the body due to the presence of Lead.

Question 113

44.The ratio of pure gold in 18 carat gold is - (A) 100% (B) 80% (C) 75% (D) 60%

Answer 113

(C) [SSC CPO 2005, SSC MTS 1999] Exp: Purity of gold is measured in carat. 24 carat gold is pure gold% of pure gold in 18 carat gold can be found by following method 18 24 ×100 = 75%

Question 114

46.85. Purity of gold is expressed in terms of carat. Purest form of gold is- (A) 24 Carat (B) 99.6 Carat (C) 91.6 Carat (D) 22 Carat

Answer 114

(A) [SSC CPO 2007] Exp: Purity of gold is expressed in terms of carat. Purest form of gold is 24 carat.

Question 115

47.The King of metal is - (A) Gold (B) Silver (C) Iron (D) Aluminum

Answer 115

(A) [SSC MTS 2002, SSC CHSL 2015] Exp: Gold is the most valuable metal, so it is known as king of metal.

Question 116

48.Standard 18 carat Gold sold in the Market is - (A) 82 parts of gold and 18 parts of Metal (B) 18 parts of gold and 82 parts other metal (C) 18 parts gold and 6 parts other metal (D) 9 parts gold and 15 parts other metal

Answer 116

(C) [SSC Sec off. 2006] Exp: Standard 18 carat Gold Sold in Market Contains 18 parts Gold and 6 Parts of Metal.

Question 117

49.Which one of the following is known as the brown coal? (A) Anthracite (B) Bituminous (C) Coke (D) Lignite

Answer 117

(D) [SSC CHSL Exam, 2011] Exp: Quality of coal depends upon the amount of carbon present in it. Due to the High temperature and pressure in earth cast peat coal (Less than 50% carbon) formed, then lignite coal (60-70% Carbon) formed, Bituminous coal (60-80% carbon) and then of Best quality of coal Anthracite (85-90% carbon). Lignite coal is also known as Brown coal.

Question 118

50.Which one of the following is not a coal variety? (A) Bituminous (B) Lignite (C) Peat (D) Dolomite

Answer 118

(D) Exp: Depending upon the quantity of carbon% coal are of four type- 1. Peat coal Carbon content 50 - 60%. It is lowest grade of coal. 2. Lignite coal Carbon content 65 - 70%. It is known as brown coal 3. Bituminous coal Carbon content 70-85%. It is also known as soft coal. 4. Anthracite coal Carbon content 90% - 95%. It is the best grade of coal.

Question 119

51.Which of the following elements behave chemically both as Metal and a Non-metal? (A) Argon (B) Carbon (C) Xenon (D) Boron

Answer 119

(D) [SSC CPO 2015] Exp: Boron behaves chemically both as Metal and a Non- Metal. It belongs to 13th group of periodic table.

Question 120

52.Which of the following metal has maximum electrical conductivity? (A) Copper (B) Aluminium (C) Silver (D) Lead

Answer 120

(C) [SSC DEO 2008] Exp: Silver has maximum electrical conductivity and thermal conductivity order of conductivity is as follows: Silver > Copper > Aluminium > Lead.

Question 121

92. Illumination of Metal is caused by the - (A) High density due to close packing of atoms (B) Highly Polished (C) Reflection of Light due to presence of free electrons (D) Absorption of Light due to presence of sockets.

Answer 121

(C) [SSC CPO 2007] Exp: Cause of illumination of metals is the reflection of light due to the presence of free electrons.

Question 122

53.Heavy metals got their names because compared to others atoms they have (A) Higher atomic mass (B) Higher atomic radii (C) Higher densities (D) Higher atomic number

Answer 122

(C) [SSC CGL 2015] Exp: Heavy metals have higher densities as compare to lighter metals. Metals having densities greater than 5g/cm3 are categorized as heavy metals. For example Cadmium, Copper, Lead etc.

Question 123

54.Which of the following is the most bad conductor? (A) Iron (B) Lead (C) Silver (D) Gold

Answer 123

(B) [SSC MTS 2006] Exp: In metals Lead is the most bad conductor, while gold, Silver and Iron are good conductors.

Question 124

55.Which metal is protected by the layer of its own oxide? (A) Silver (B) Iron (C) Aluminium (D) Calcium

Answer 124

(C) [SSC CHSL 2012] Exp: Aluminium is the metal which protects itself by the rusting with its own layer of oxide.

Question 125

56.The ore of only two metals that are Non-Silver in colour, they are- (A) Nickel and zinc (B) Copper and gold (C) Palladium and platinum (D) Sodium and magnesium

Answer 125

(B) [SSC CHSL Exam, 2015] Exp: From the given options, Only Gold and Copper are non-silver in colour. Gold is of Golden and Copper is of Reddish Brown Colour.

Question 126

57.The Soft Silvery Metallic element which ionizes easily when heated or exposed to Light and it present in atomic clocks is- (A) Californium (B) Cesium (C) Calcium (D) Cerium

Answer 126

(B) [SSC CGL Exam, 2015] Exp: Cesium has least melting points from the given Metals and is easily ionized when exposed to Light. It is also used in Atomic Clocks.

Question 127

58.Which one of the following metals cannot be used as an electromagnet? (A) Iron (B) Copper (C) Nickel (D) Cobalt

Answer 127

(B) [SSC MTS 2008] Exp: Iron, Nickel and Cobalt are Magnetic Materials so these can be used as electromagnet but copper cannot be used as electromagnet.

Question 128

59.Quartz is a type of - (A) Silicon dioxide (B) Sodium silicate (C) Aluminium oxide (D) Magnesium carbonate

Answer 128

(A) [SSC CGL 2006] Exp: Quartz is the crystalline form of silicon dioxide.

Question 129

60.Which one of the following is used in Pencils? (A) Charcoal (B) Graphite (C) Sulphur (D) Phosphorus

Answer 129

(B) [SSC CGL 2014] Exp: Graphite is used in the making of Pencils. It is an allotrope of carbon.

Question 130

61.In Graphite layers are held together by- (A) Vander waal forces (B) Metallic bond (C) Ionic bond (D) Covalent bond

Answer 130

(A) [SSC CHSL 2012] Exp: In graphite, Layers are Held together by Vander walls forces. These are weak attractive forces between atoms or non-polar molecules. It is named after dutch scientist Johannes Diderik Van Vander Wall.

Question 131

62.Which one among the following is Lubricant? (A) Germanium (B) Sulphur (C) Graphite (D) Indium

Answer 131

(C) [SSC CHSL 2012] Exp: Solid Lubricants are the substances in which the friction between two layers is reduced due to their solid State. Graphite, Tungsten disulphide, Molybdenum disulphide are important solid lubricants

Question 132

63.Diamond is harder than Graphite because of- (A) Difference of layers of atom (B) Tetrahedral structure of diamond (C) Difference of crystalline structure (D) None of these

Answer 132

(C) Exp: In diamond, 4 valence electrons of a carbon atom forms strong covalent bond and form tetrahedral structure due to sp3 hybridisation. Graphite is hexagonal layered structure and it is soft. Due to difference in crystalline structure diamond is harder than graphite.

Question 133

64.One carat of Diamond is equal to - (A) 100 mg (B) 150 mg (C) 200 mg (D) 250 mg

Answer 133

(C) [SSC CHSL 2011] Exp: One carat of Diamond is equal to 200 mg.

Question 134

65.Which of the following property is generally found in non metals? (A) Brittleness (B) Conductivity (C) Ductility (D) Malleability

Answer 134

(A) [SSC CHSL 2011] Exp: The solid material which breaks into small pieces on hammering are called brittle. The non-metals are generally brittle in nature.

Question 135

66.Fire-Fighting clothes are made from- (A) Mica (B) Asbestos (C) Talc (D) Steatite

Answer 135

(B) [SSC CHSL 2011] Exp: Fire-Fighting Cloths are made from Asbestos because it has heat resistant property.

Question 136

67.Fullerene is a newly discovered crystalline carbon allotrope, contains- (A) 100 C atoms (B) 80 C atoms (C) 60 C atoms (D) 40 C atoms

Answer 136

(C) [SSC CHSL 2012] Exp: Fullerene is a newly discoverd crystalline carbon allotrope contains 60 C atoms. It was discovered by R.E. smalley and R.F. Curl and H.W. Kroto for this discovery these scientist shared the 1996 Noble Prize in chemistry. Fullerences (C60) are the only pure form of Carbon. It is also known as Buckminster fullerene or bucky ball.

Question 137

68.Chile saltpeter is the common name of- (A) Potassium Nitrate (B) Sodium Nitrate (C) Sodium Nitrite (D) Potassium Nitrite

Answer 137

(B) [SSC CHSL Exam, 2015] Exp: Chilesalt peter is the common name of sodium nitrate (NaNO3).

Question 138

69.Which among the following elements is a liquid at room temperature? (A) Phosphorus (B) Mercury (C) Sodium (D) Aluminium

Answer 138

(B) (SSC CHSL 2016) Exp: Mercury is the only metal which exists in liquid state at room temperature. This is due to weak metallic bonding as in mercury as it has fulfilled valence orbitals.

Question 139

70.Wh ich among the fo llowing is white phosphorus? (A) P1 (B) P6 (C) P4 (D) P5

Answer 139

(C) (SSC CHSL 2016) Exp: White phosphorus consists of P4 units. It glows in dark (property known as chemiluminiscence) due to its slow oxidation. It is most reactive allotrope of phosphorous.

Question 140

71.Alkali metals can (A) Be highly unstable at room temperature (B) Vaporize at room temperature (C) Easily gain electrons (D) Easily lose electrons

Answer 140

(D)Exp: First Group of periodic table contains lithium (Li), Sodium (Na), Potassium (K), Rubidium (Rb), Cesium (Cs) and Francium (Fr). These are called as alkalimetals since their hydroxies form strong bases or alikali. The first ionization enthalpies of the alkali metals are very low. So they easily lose electrons.

Question 141

72.Which among the following has the maximum density? (A) Water (B) Ice (C) Ethylene (D) Acetone

Answer 141

(A) (SSC CHSL 2016) Exp: Water has the maximum density.

Question 142

73.Who discovered Nitrogen? (A) Faraday (B) Heisenberg (C) Hooke (D) Rutherford

Answer 142

(D) (SSC CHSL 2016) Exp: Nitrogen was discovered by Dainel Rutherford in 1772. In the molecular form, it exists as diatomic molecule (N2) having triple bond between two nitrogen atoms. Dinitrogen is chemically inert at room temperature.

Question 143

74.Which of the following gases is present in the atmosphere can be detected by its odour? (A) Ethane (B) Sulphur dioxide (C) Hydrogen (D) Carbon monoxide

Answer 143

(B) (SSC CHSL 2016) Exp: In the given options, Sulphur dioxide is toxic gas with a pungent and suffocation odour while ethane, hydrogen and carbon monoxide are odourless.

Question 144

75.If water smells bad, then that odour can be removed by adding (A) Alum (B) Bleach (C) Activated carbon (D) Deactivated nitrogen

Answer 144

(C) (SSC CHSL 2016) Exp: Activated carbon is also called Activated charcoal due to its high degree of micro- porosity. It acts as an adsorbent.

Question 145

76.Which of these is not a macronutrient for Plants? (A) Nitrogen (B) Phosphorous (C) Potassium (D) Chlorine

Answer 145

(D) (SSC CHSL 2016) Exp: Macronutrients are nutrients that are required in larger amount by plants. eq: Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorous Potassium, Calcium, Sulphur, Magnesium.

Question 146

77.Which of the following elements has the lowest melting point? (A) Platinum (B) Carbon (C) Cobalt (D) Krypton

Answer 146

(D) (SSC CHSL 2016) Exp: In the given options krypton is a gas. So krypton has the lowest melting point. Order of Melting Point:- Gas < liquid < solid.

Question 147

78.Why metals conduct electricity? (A) Because of low melting point (B) Because of high tensile strength (C) Because of free electrons (D) Because of high atomic density

Answer 147

(C) (SSC CHSL 2016) Exp: Conduction of electricity in metals is possible due to presence of free electrons.

Question 148

79.Density of water is maximum at ______. (A) 12 degree celsius (B) 8 degree celsius (C) 4 degree celsius (D) 0 degree celsius

Answer 148

(C) (SSC CHSL 2016) Exp: Water has maximum density (1 g cm-3) at 4ºC. This property is very useful for aquatic life. In severe cold, the upper layer of the sea water freezes. The heavier water has more density than that of ice is present below the surface of ice. The ice layer formed on the surface of a lake in winter does not sink to the bottom. Ice provides a thermal insulation for the water below it. The sea animals can live safely in water under these conditions.

Question 149

80.Which of the following elements has the lowest melting point? (A) Bromine (B) Zinc (C) Lead (D) Calcium

Answer 149

(A) (SSC CHSL 2016) Exp: Bromine is a nonmetal so it has lowest melting point. Non-metals have low melting point compared to metals.

Question 150

81.Heavy water is_____. (A) Monoterium oxide (B) Polyterium oxide (C) Deuterium oxide (D) Trislum oxide

Answer 150

(C) (SSC CHSL 2016) Exp: Heavy water is D2O. (Deuterium oxide).

Question 151

82.Solid carbon dioxide is known as ________. (A) Hypo (B) Borax (C) Alum (D) Dry ice

Answer 151

(D) (SSC CHSL 2016) Exp: Solid carbon dioxide is known as dry ice. Dry ice is also called Cardice. Dry ice shows sublimation. It is used for making cold baths, used as coolant for preserving perishable articles in food industry, for curing local burns and in hospitals for surgical operations.

Question 152

83.Who discovered Oxygen? (A) Carl Scheele (B) Hooke (C) Heisenberg (D) Williams

Answer 152

(A) (SSC CHSL 2016) Exp: Oxygen was discovered by carl wilhelm scheele in 1772 and Joseph Priestley in 1774 but Priestley is given priority because his work was published first, but it is not given in options.

Question 153

“84.Which of the following gases is known as ““Laughing Gas””?(A) Nitrous oxide (B) Nitrogen peroxide (C) Nitrogen (D) Nitric oxide”

Answer 153

(A) (SSC CGL 2016) Exp: Nitrous oxide is known as laughing gas. Mixture of nitrous oxide and oxygen is used as anaesthetic.

Question 154

85.Which of the following statement is false? (A) Radon is obtained from the decay of radium. (B) Helium is an inert gas (C) Xenon is the most reactive among the rare gases (D) The most abundant rare gas found in the atmosphere is Radon.

Answer 154

(D) Exp: In the given options statement (D) is false. While (A), (B) and (C) are true. Radon is obtained from decay of radium. 226 222 4 Ra Rn + He 88 86 2 Helium is an inert gas due to stable configuration. Xenon is the most reactive among rare gases due to low ionisation enthalpy. The most abundant rare gas found in the atmosphere is Argon.

Question 155

86.The Chemical formula of Cadmium nitrate is _____. (A) Cd(NO3) 2 (B) CdNO3 (C) Cd2(NO4C)2 (D) Cd2NO3

Answer 155

(A) (SSC CHSL 2016) Exp: Cadmium ion - Cd2+ Nitrate ion - NO3 - Chemical formula of cadmium nitrate is Cd (NO3) 2

Question 156

87.The common name of hydrogen peroxide is (A) Borax (B) Bleach (liquid) (C) Baking soda (D) Gypsum

Answer 156

(B) (SSC CHSL 2016) Exp: Common name of hydrogen peroxide is bleach (liquid) because H2O2 is used as bleaching agent for delicate materials like textiles (silk, wool) paper pulp, straw, leather, ivory, oils and fats.

Question 157

88.Which of the following elements has the lowest melting point? (A) Sodium (B) Tin (C) Radon (D) Radium

Answer 157

(C) (SSC CHSL 2016) Exp: Radon has the lowest melting point due to weak vander waal force in noble gases. It is a non-metal. Noble gases have low melting point and boiling point compared to other elements.

Question 158

89.Barium loses ____ electrons to achieve noble gas electron configuration. (A) 1 (B) 2 (C) 3 (D) 4

Answer 158

(B) (SSC CHSL 2016) Exp: Barium loses 2 electrons to achieve noble gas electronic configuration.

Question 159

90.The common name of sodium tetraborate decahydrate is _____. (A) Epsom salt (B) Gypsum (C) Borax (D) Galena

Answer 159

(C) (SSC CHSL 2016) Exp: The common name of sodium tetraborate decahydrate is Borax (Na2B4O7.10H2O

Question 160

91.The Chemica l formu la of Ammonium dichromate is _____. (A) (NH4) 2Cr2O7 (B) (NH4)CrO3 (C) (NH4)Cr2O3 (D) (NH4) 2Cr2O3

Answer 160

(A) (SSC CHSL 2016) Exp: Ammonium ion - NH4 + Chromate ion - Cr2O7 -2 Chemical formula of Ammonium dichromate is (NH4) 2Cr2O7

Question 161

92.Which gas among the following used as an anaesthetic? (A) Methane (B) Carbon dioxide (C) Nitrous oxide (D) Nitrogen

Answer 161

(C) [SSC FCI 2012] Exp: Nitrous oxide gas is used as a mild anaesthetic in dental and other minor surgical operations when mixed with 10% O2.

Question 162

93.Which of the following elements has the lowest melting point? (A) Titanium (B) Tungsten (C) Argon (D) Nickel

Answer 162

(C) (SSC CHSL 2016) Exp: Noble gases have low melting point and boiling point compared to other elements. Argon is a noble gas

Question 163

94.The common name of sulphur is (A) Freon (B) Galena (C) Lime (D) Brimstone

Answer 163

(D) (SSC CHSL 2016) Exp: The common name of sulphur is brimstone.

Question 164

135. The Chemical formula of Aluminium Chloride is _____. (A) AlCl (B) AlCl2 (C) AlCl3 (D) Al2Cl3

Answer 164

(C) (SSC CHSL 2016) Exp: Aluminium ion = Al3+ Chloride ion = Cl- Chemical formula of Ammonium Chloride = AlCl3

Question 165

136.The Chemical formula of Ammonium Oxalate is _____. (A) (NH4) 2C2O4 (B) (NHD)2CO4 (C) (NHD)2C2O4 (D) (NHD)2C2O3

Answer 165

(A)Exp: Ammonium ion:- NH4 + Oxalate ion:- C2O4 2- Chemical formula of Ammonium oxalate is :- (NH4) 2 C2O4

Question 166

137. Chemical Formula of Water is _____ . (A) O2 (B) N2O (C) NaOH (D) H2 O

Answer 166

(D) (SSC CHSL 2016) Exp: Chemical formula of water is H2O. 2 atoms of H and 1 atom of O combines to make 1 molecule of water.

Question 167

137.The Chemical formula of Ammonium sulphate is (A) NH4SO4 (B) (NH4) 2SO3 (C) NH4SO3 (D) (NH4) 2SO4

Answer 167

(D) (SSC CHSL 2016) Exp: Ammonium ion - NH4 Sulphate ion - 2 SO4 - NH4 2 SO4 - (NH4) 2SO4 So the chemical formula of Ammonium sulphate will be (NH4) 2SO4

Question 168

138.Which of the following elements has the lowest melting point? (A) Platinum (B) Sodium (C) Antimony (D) Krypton

Answer 168

(D) (SSC CHSL 2016) Exp: In the given options krypton has the lowest melting point because it is a noble gas (inert gas). Noble gases have low melting point and boiling point compared to other elements.

Question 169

139.The common name of Magnesium Sulphate heptahydrate is (A) Epsom salt (B) Borax (C) Gypsum (D) Lime

Answer 169

(A) (SSC CHSL 2016) Exp: Common name of Magnesium Sulphate hepta hydrate is Epsom salt (MgSO4.7H2O).

Question 170

140.Which of the following elements has the lowest melting point? (A) Helium (B) Potassium (C) Tungsten (D) Sulphur

Answer 170

(A) (SSC CHSL 2016) Exp: Helium is a noble gas (inert gas) so it has lowest melting point. Noble gases have low melting point and boiling point compared to other elements

Question 171

141.The chemical formula of Ammonia is _____ . (A) NH4 + (B) NH (C) NH2 (D) NH3

Answer 171

(D) (SSC CHSL 2016) Exp: Chemical formula of ammonia is NH3. It is manufactured in Lab by Haber process.

Question 172

143. Who discovered Fullerene (an allotrope of carbon)? (A) K Scheele (B) Richard Smalley (C) Faraday (D) Heisenberg

Answer 172

(B) (SSC CHSL 2016) Exp: In 1985, a third crystalline allotrope of carbon called fullerene was discovered collectively by three scientists namely R.E. Smalley, R.F. curl and H.W. Kroto shared the 1996 Noble prize in chemistry.

Question 173

144.Which of the following is not a Halon gas? (A) Methane (B) Carbon tetra chloride (C) Iodomethane (D) Bromomethane

Answer 173

(A) (SSC CHSL 2016) Exp: Halons are the gases which contains halogen atom as an essential element. It is used for fire suppression & refrigeration. Carbon tetra chloride, Iodomethane, and Bromomethane are Halon as they contain Halogen atom.

Question 174

145.Which of the following elements has the lowest melting point? (A) Tin (B) Hydrogen (C) Carbon (D) Sodium

Answer 174

(B) (SSC CHSL 2016) Exp: In the given options, Hydrogen is a gase

Question 175

us non metal so it has the lowest melting point. 146. The Chemical formula of Ammonium chloride is ___________. (A) (NH(D)2Cl (B) NH4Cl3 (C) NH4Cl2 (D) NH4Cl

Answer 175

(D) (SSC CHSL 2016) Exp: Ammonium ion = NH4 + Chloride ion = Cl- Chemical formula of Ammonium chloride - NH4Cl

Question 176

146.Which of the following elements has the lowest melting point? (A) Iron (B) Nitrogen (C) Iodine (D) Lead

Answer 176

(B) (SSC CHSL 2016) Exp: In the given options, Nitrogen is gaseous nonmetal so it has the lowest melting point. Iron and lead are metals while Iodine is solid nonmetal having higher melting point than the melting point of nitrogen.

Question 177

147.Filament of electric bulb is made of _____. (A) Magnesium (B) Lead (C) Tin (D) Tungsten

Answer 177

(D) (SSC CHSL 2016) Exp: Filament of electric bulb is made of Tungsten metal. Tungsten metal has highest melting point (3,422ºC).

Question 178

148.Chemical formula of Ammonia is _______. (A) PH3 (B) NO2 (C) AlN (D) NH3

Answer 178

(D)Exp: Chemical formula of Ammonia - NH3 Phosphine - PH3 Nitrogen dioxide - NO2 Aluminium nitride - AlN

Question 179

149.Which of the following elements has the lowest melting point? (A) Oxygen (B) Platinum (C) Sodium (D) Tin

Answer 179

(A) (SSC CHSL 2016) Exp: In the given options, Oxyen is a gaseous nonmetal so it has the lowest melting point. Non- metals have low melting point compared to metals.

Question 180

150.Chemical Formula of Aluminium Nitride is (A) AN (B) AlN (C) AlNi (D) ANi

Answer 180

(B) (SSC CHSL 2016) Exp: Aluminium ion - Al+3 Nitride ion - N-3 So chemical formula of Aluminium nitride will be AlN.

Question 181

151.NaHCO3 is chemical formula for ___________. (A) Borax (B) Vinegar (C) Lime (D) Baking soda

Answer 181

(D) (SSC CHSL 2016) Exp: Baking soda is sodium bicarbonate. Its chemical formula is NaHCO3.

Question 182

152.Which of the following elements has the lowest melting point? (A) Chromium (B) Hydrogen (C) Zinc (D) Silver

Answer 182

(B) (SSC CHSL 2016) Exp: In the given options, Hydrogen is gas so it has lowest melting point. Order of melting point:- Solid > liquid > gas.

Question 183

153.Which of the following elements has the lowest melting point? (A) Boron (B) Calcium (C) Neon (D) Gold

Answer 183

(C) (SSC CHSL 2016) Exp: In the given options, Neon is noble gas so it has lowest melting point. Noble gases have low melting point and boiling point compared to other elements.

Question 184

154.The Chemical formula of Ammonium nitrate is ___________. (A) (NHB)2NO3 (B) NH4NO3 (C) NH4(NOC)2 (D) NH2NO3

Answer 184

(B) (SSC CHSL 2016) Exp: Ammonium ion - NH4 Nitrate ion - NO3 - So chemical formula of ammonium nitrate will be NH4NO3.

Question 185

155.Which of the following elements has the lowest melting point? (A) Xenon (B) Iodine (C) Barium (D) Magnesium

Answer 185

(A) (SSC CHSL 2016) Exp: In the given options, Xenon is a noble gas (inert gas). So it has the lowest melting point. Noble gases have low melting point and boiling point compared to other elements.

Question 186

156.Which of the following elements has the lowest melting point? (A) Titanium (B) Sulphur (C) Argon (D) Zinc

Answer 186

(C) (SSC CHSL 2016) Exp: Argon is a noble gas (inert gas) so it has lowest melting point. Noble gases have low melting point and boiling point compared to other elements.

Question 187

157.Which of the following elements has the lowest melting point? (A) Oxygen (B) Gold (C) Silver (D) Manganese

Answer 187

(A) (SSC CHSL 2016) Exp: In the given options, Oxygen is a nonmetal so it has lowest melting point. Non- metals have low melting point compared to metals.

Question 188

158.What is washing soda? (A) Aluminium bicarbonate (B) Sodium bicarbonate (C) Aluminium sulphate (D) Sodium carbonate

Answer 188

(D) (SSC CHSL 2016) Exp: Washing soda is chemically known as sodium carbonate decahydrate (Na2CO3.10H2O).

Question 189

159.Which of the following elements has the lowest melting point? (A) Zinc (B) Titanium (C) Sulphur (D) Fluorine

Answer 189

(D) (SSC CHSL 2016) Exp: In the given options Fluorine is nonmetal so it has lowest melting point. Non- metals have low melting point compared to metals. Sulphur has higher melting point compared to fluorine.

Question 190

160.Which of the following is false? (A) Hydrogen atom is roughly a third of the mass of tritium (B) Deuterium is called heavy hydrogen (C) Deuterium atom has 1 neutron (D) Protium is the rarest isotope of hydrogen

Answer 190

(D) (SSC CHSL 2016) Exp: Hydrogen has three isotopes. These are called - (i) Protium or ordinary hyrdogen [1 1H]- it is most abundant isotope of hydrogen.(ii) Deuterium or heavy hydrogen [2 1H or D]. (iii) Tritium [3 1Hor T] :- It is the least abundant of all isotopes of hydrogen. Atomic properties of isotopes of Hydrogen. Property H D T Relative(%) 99.985 0.0156 10-15 Abundance Relative Atomic 1.007825 2.014102 3.016049 Mass(gmol-1)

Question 191

161.Zeolite is (A) Hydrated ferric oxide (B) Hydrated sodium aluminium silicate (C) Sodium hexametaphosphate (D) Sodium tetraborate

Answer 191

(B) (SSC CGL 2016) Exp: Hydrated sodium aluminium silicates, (Na2Al2Si2O8.xH2O) is known as Zeolite. It has property of exchanging Ca+2 and Mg+2 ions present in hard water with sodium present in it. Zeolite can be represented by the general formula Na2Z where Z = Al2Si2O8. xH2O.

Question 192

162.Helium is added to the oxygen supply of deep sea divers because it is_______ (A) Less poisonous than nitrogen (B) Lighter than nitrogen (C) Readily miscible with oxygen (D) Less soluble in blood than nitrogen at high pressure

Answer 192

(D) (SSC CGL 2016) Exp: Helium-Oxygen mixture is used by deep sea divers in preference to nitrogen oxygen mixture because of its very low solubility in blood.

Question 193

163.Water is used in a hot water bag because (A) It is easily available (B) It has high specific gravity (C) It has high specific heat (D) It is a liquid substance

Answer 193

(C) (SSC CGL 2016) Exp: Water is used in hot water bag because it has high specific heat. The specific heat of water is 1 calorie/ gramºC or 4.186 joule/gramºC which is higher than any other common substance.

Question 194

164.What is contained in Chlorophyll? (A) Sodium (B) Potassium (C) Manganese (D) Magnesium

Answer 194

(D) (SSC CGL 2016) Exp: Magnesium metal in the form of Mg+2 ions are present in chlorophyll a, the green colour pigment of plants, which absorb light and is essential for photosynthesis.

Question 195

165.What is the product formed when sodium bicarbonate is heated strongly? (A) Sodium carbonate (B) Sodium hydroxide (C) Sodium peroxide (D) Sodium monoxide

Answer 195

(A) (SSC CGL 2016) Exp: When sodium bicarbonate (NaHCO3) is strongly heated it gives sodium carbonate. 2NaHCO3 Na2CO3 + CO2 + H2O

Question 196

166.The most pure form of carbon among the options is (A) Anthracite (B) Lampblack (C) Graphite (D) Wood Charcoal

Answer 196

(C) (SSC CGL 2016) Exp: The most pure form of carbon among the options is graphite because other forms of elemental carbon like carbon black, coke and charcoal are all impure. Anthracite has 90-95% carbon content.

Question 197

167.Activated Charcoal is used to remove colouring matter from pure substances by ____. (A) Bleaching (B) Oxidation (C) Adsorption (D) Reduction

Answer 197

(C) (SSC CGL 2016) Exp: Charcoal is an amorphous allotropic form of carbon. Charcoal is highly porous substance and can adsorb many times their own volume of gases. Its adsorption capacity can be further increased by heating at 1273K in a current of super heated steam. Charcoal thus prepared is called activated charcoal.

Question 198

168.Silica gel is a (A) Moisturizer (B) Flavouring agent (C) Drying agent (D) Delicious food

Answer 198

(C) (SSC CGL 2016) Exp: Silica gel acts as drying agent. Silica gel is a amorphous form of silica or Silicon dioxide (SiO2). It is very porous and it contains about 4% water. To protect merchandise from moisture during storage, small packets of dry silica gel are placed in packing boxes.

Question 199

169.Silver gets corroded due to _______ in air. (A) Oxygen (B) Hydrogen sulphide (C) Carbon dioxide (D) Nitrogen

Answer 199

(B) (SSC CGL 2016) Exp: Silver gets corroded by reacting with hydrogen Sulphide in the air to form black Silver Sulphide compound.

Question 200

170.Which of the metals has the maximum thermal conductivity? (A) Iron (B) Aluminium (C) Silver (D) Copper

Answer 200

(C) (SSC CGL 2016) Exp: Silver metal has maximum thermal conductivity in the given options. Increasing order of thermal conductivity at 25ºC for various metals. Platinum < Iron < Tungsten < Aluminium < Gold < Copper < Silver.

Question 201

171.Which one of the following forms of phosphorous is most reactive? (A) Black Phosphorous (B) White Phosphorous (C) Voilet Phosphorous (D) Red Phosphorous

Answer 201

(B) (SSC CGL 2016) Exp: Three main allotropic form of Phosphorous are (A) White phosphorous, (B) Red phosphorous (C) Black phosphorous. White phosphorous is more reactive than the other because of angular strain in P4 molecule where the angles are only 60° in other forms.

Question 202

172.Magnesium is a constituent metal of ______________. (A) Chlorophyll molecule (B) DNA (C) Mitochondria (D) Ribosomes

Answer 202

(A) (SSC CGL 2016) Exp: Magnesium is a constituent metal of chlorophyll molecule.

Question 203

173.Name the gas used in preparation of bleaching powder (A) Oxygen (B) Hydrogen (C) Nitrogen (D) Chlorine

Answer 203

(D) (SSC CGL 2016) Exp:When chlorine gas is passed through dry slaked lime, bleaching powder (CaOCl2) is formed. It is also called chloride of lime. Its chemical name is Calcium OxyChloride. Ca(OH)2 + Cl2 CaOCl2+ H2O

Question 204

174.Phosphorous is kept in water because (A) Its ignition temperature is very high (B) Its ignition temperature is very low (C) Its critical temperature is high (D) Its critical temperature is low

Answer 204

(B) (SSC CGL 2016) Exp: White phosphorus (P4) has very low ignition temperature (303 K) and therefore it catches fire in air so it is generally stored in under water.

Question 205

175.In arc welding Argon is used because of its (A) Low reactivity with metal (B) Ability to lower the melting point of the metal (C) High flammability (D) High calorific value

Answer 205

(A) (SSC CGL 2016) Exp: Argon is used to protect metal surfaces from oxidation during the welding of steel. It is used to provide an inert atmosphere in metallurgical processes.

Question 206

176.Inert gases are (A) Miscible with water (B) Not stable (C) Chemically unreactive (D) Chemically very active

Answer 206

(C) (SSC CGL 2016) Exp: The group 18 consist of elements He, Ne, Ar, Kr, Xe, and Rn. These gases at ordinary temperature do not have chemical reactivity and therefore, they are called inert gases.

Question 207

177.Which of the following fuels causes minimum environmental pollution? (A) Diesel (B) Kerosene (C) Hydrogen (D) Coal

Answer 207

(C) (SSC CGL 2016) Exp: Hydrogen is used as an efficient fuel because It has many advantages over conventional fossil fuels. It does not produce any pollution and releases larger energy per unit mass of fuel in comparison to gasolene and other fuels. 2H2 + O2 2H2O

Question 208

178.Which of the following is the most important raw material for generation of power in India? (A) Mineral Oil (B) Natural Gas (C) Uranium (D) Coal

Answer 208

(D) (SSC CGL 2016) Exp: In India, coal is the bulk of primary energy contributor with 56.90% share.

Question 209

180. The purest form of water in nature is (A) Rain water (B) Lake water (C) River water (D) Sea water

Answer 209

(A) (SSC CGL 2016) Exp: The purest form of water in nature is rain water.

Question 210

181.Highest percentage of carbon is found in which form of coal? (A) Anthracite (B) Bituminous (C) Peat (D) lignite

Answer 210

(A) (SSC CGL 2016) Exp: Highest percentage of carbon is found in Anthracite coal. It contains 92-98% carbon.

Question 211

182.Which one of the following is a good electrical conductor? (A) Graphite (B) Diamond (C) Peat (D) Charcoal

Answer 211

(A) (SSC CGL 2016) Exp: Since only three electrons of each carbon are used in making hexagonal rings in graphite, fourth valence electron of each carbon is free to move. This makes graphite a good conductor of heat and electricity.

Question 212

183.Which of the following acts as best adsorbent? (A) Charcoal (B) Activated Charcoal (C) Activated Coconut Charcoal (D) Carbon black

Answer 212

(C) (SSC CGL 2016) Exp: In the given options, activated coconut charcoal acts as best adsorbent. It has predominantly pores in micro pore range. Almost 85-90% surface are of a coconut shell exist as micropores. These small pores match the size of contaminant molecules in drinking water and therfore are very effective in trapping them.

Question 213

184.Which of the following metal has the least melting point? (A) Gold (B) Silver (C) Mercury (D) Copper

Answer 213

(C) [SSC CHSL 2014] Exp: Mercury metal has the lowest melting point because it is found in liquid state at room temperature.

Question 214

185.Which of the following elements has the lowest melting point? (A) Iodine (B) Lead (C) Tin (D) Mercury

Answer 214

(D) (SSC CHSL 2016) Exp: Mercury metal has the lowest melting point because it is found in liquid state at room temperature.

Question 215

186.Which is the highest quality of hard coal? (A) Anthracite (B) Bituminous (C) Lignite (D) Peat

Answer 215

(A) (SSC CGL 2016) Exp: Anthracite coal is much harder than other forms of coal, so it is known as hard coal. It contains about 90- 95% Carbon.

Question 216

187.Which of the following metal is the heaviest? (A) Iron (B) Silver (C) Nickel (D) Osmium

Answer 216

(D) (SSC CPO 2017) Exp: Osmium is the heaviest element in periodic table as it has the highest density.

Question 217

188.Which of the following metal has the lowest density? (A) Lithium (B) Iron (C) Gold (D) Vanadium

Answer 217

(A) (SSC CPO 2017) Exp: Lithium is the lightest solid metal & has lowest density. Lithium is reactive alkali metal.

Question 218

189.Which of the following is the most reactive in nature? (A) Potassium (B) Calcium (C) Lead (D) Copper

Answer 218

(A) (SSC CPO 2017) Exp: Potassium is the most reactive in nature. So, it is not found naturally in its elemental form. Due to its reactive nature, it is kept under the Kerosene oil.

Question 219

190.Which of the following is not a property of a metal? (A) Hardness (B) Lustrous (C) Malleability (D) Poor conductivity of heat

Answer 219

(D) (SSC CPO 2017) Exp: Metals are hard, lustrous & malleable. Hardness:- Metals are hard due to Metallic bonding. Lustrous:- On exposure of light, metals emit electrons from its surface, so they are lustrous (shiny in appearance). Malleability:- Property of metals by which they can be converted into sheets. Conductor :- Metals are good conductor of heat & electricity due to free electrons.

Question 220

191.Which of the following is an Inert gas? (A) Hydrogen (B) Nitrogen (C) Oxygen (D) Argon

Answer 220

(D) (SSC CGL 2017) Exp: Helium (He), Neon (Ne), Argon (Ar), Krypton (Kr), Xenon (Xe) & Radon (Rn) are inert or noble gases due to completely filled stable configuration.

Question 221

192.Which of the following cannot be beaten into Sheets? (A) Gold (B) Silver (C) Potassium (D) Aluminium

Answer 221

(C) (SSC CGL 2017) Exp: Property of a metal by which it can be beaten into sheets is called as Malleability. eg:- Aluminium, Gold & Silver can be beaten into sheets while potassium cannot be beaten into sheets because of its high reactivity.

Question 222

193.Magnesium (Mg) + Oxygen (O) =? (A) Mg2O (B) MgO4 (C) O2Mg (D) MgO

Answer 222

(D) (SSC CGL 2017) Exp: 2 Mg + O2 2 MgO When Magnesium is burnt in presence of O2, a powder is formed i .e MgO (Magnesium Oxide)

Question 223

194.Metals react with sodium hydroxide to produce ___________. (A) Oxygen gas (B) Sodium (C) Water (D) Hydrogen gas

Answer 223

(D) (SSC CGL 2017) Exp: Amphoteric metals reacts with sodium hydroxide to produce hydrogen gas. 2Al Amphoteric metal + 2NaOH Sodium hydroxide + 2H O2 Water 2NaAlO + 3H 2 2 Sodium aluminate Hydrogen gas

Question 224

195.Magnesium oxide (MgO) + Water (H2O) =? (A) [Mg(OH)] (B) [Mg2(OH)] (C) [Mg(O2H)2] (D) [Mg(OH)2]

Answer 224

(D) (SSC CGL 2017) Exp: MgO + H2O Mg(OH)2 Mg(OH)2 is basic in nature & it is used as an antacid.

Question 225

196.What is formed when Magnesium is burnt? (A) Baking Soda (B) Calcium Carbonate (C) Ash (D) Vinegar

Answer 225

(C) (SSC CGL 2017) Exp: When Magnesium is burnt in air, it forms a white powder i.e. Magnesium oxide, which is called as Ash.

Question 226

197.The property of metal by which it can be drawn into wires is called _____________. (A) Malleability (B) Viscosity (C) Ductility (D) Tensile strength

Answer 226

(C) (SSC CGL 2017) Exp: Ductility is a property of a metal by which it can be converted into wires. Gold is the most ductile & malleable metal.

Question 227

198.The property of metals by which they can be beaten into thin sheets is called _______________. (A) Ductility (B) Malleability (C) Viscosity (D) Tensile strength

Answer 227

(B) (SSC CGL 2017) Exp: The property of metals by which they can be beaten into thin sheets is called Malleability. Gold is the most ductile & malleable metal.

Question 228

1.Which among the following is used in making liquors, medicines and as a fuel in aircrafts? (A) Propyl alcohol (B) Dimethyl alcohol (C) Ethyl alcohol (D) Methyl alcohol

Answer 228

(C) (SSC CHSL 2016) Exp: Ethyl Alcohol or Ethanol (C2H5OH) is used for making liquors, medicines and as a fuel in aircrafts. Note: 1. 100% pure alcohol is known as absolute alcohol.

Question 229

2.Power alcohol is a mixture of 20% Alcohol and 80% petrol. 2. Ethane gas has a slightly ______ taste. (A) Sweet (B) Bitter (C) Sour (D) Salty

Answer 229

(A) (SSC CHSL 2016) Exp: Ethane gas has a slightly sweet taste.

Question 230

3.The Chemical formula of Urea is (A) (NH)2CO2 (B) (NH)CO (C) (NH)2CO (D) (NH2) 2CO

Answer 230

(D) (SSC CHSL 2016) Exp: The chemical formula of Urea is NH2CONH2 or (NH2) 2CO. Urea was the first organic compound which is prepared by Friedrich Wohler in the laborary in 1828 from inorganic compound ammonium cyanate.

Question 231

4.Alkenes were earlier known as ______. (A) Paraffins (B) Titoffins (C) Olefins (D) Meloffins

Answer 231

(C) (SSC CHSL 2016) Exp: Alkenes were earlier known as Olefins (Greek: Olefiant = oil forming) since the lower members of alkenes forms oily product on reaction with halogens such as chlorine and bromine.

Question 232

5.Decane has how many hydrogen atoms? (A) 22 (B) 33 (C) 11 (D) 44

Answer 232

(A) (SSC CHSL 2016) Exp: In decane ‘Dec’ represent 10 carbon atoms while ‘ane’ represent it is an alkane. General formula of alkane is CnH2n+2 where ‘n’ represents no. of carbon atoms. Decane - C10H2×10+2 = C10H22 So, 22 hydrogen atoms are present in Decane.

Question 233

6.Carcinogenic chemicals cause (A) Heart diseases (B) Diabetes (C) Cancer (D) Asthma

Answer 233

(C) (SSC CHSL 2016) Exp: Carcinogenic are the agents or substances which causes cancer. Benzene and most of the polynuclear aromatic hydrocarbons are Carcinogenic. Examples: 1,2 - Benzopyrene, 1,2 - benzanthracene etc.

Question 234

7.Aromatic hydrocarbons contain at least ____benzene like ring in their molecules. (A) Four (B) Three (C) Two (D) One

Answer 234

(D) (SSC CHSL 2016) Exp: Hydrocarbons and their alkyl, alkenyl and alkynl derivatives which contain one or more-benzene rings either fused or isolated in their molecules are called aromatic hydrocarbons. They are also called arenes (Aromatic alkenes)

Question 235

8.Pentane has ____ structural isomers. (A) 1 (B) 2 (C) 3 (D) 4

Answer 235

(C) (SSC CHSL 2016) Exp: Pentane (C5H12) has three structural isomers. 1. CH3 - CH2 - CH2 - CH2 - CH3 2. CH - 3 CH - CH - CH 2 3 CH3 3. CH 3 C CH 3 CH 3 CH 3

Question 236

9. What is used to prevent freezing of fuel in space crafts? (A) Benzene (B) Glycol (C) Acetylene (D) Ester

Answer 236

(B) (SSC CHSL 2016) Exp: Ethylene Glycol is used to prevent freezing of fuel in space crafts.

Question 237

9.Which among the following is used to generate light, to weld metals? (A) Ethylene (B) Acetylene (C) Glycol (D) Oxalic acid

Answer 237

(B) (SSC CHSL 2016) Exp: Acetylene reacts with oxygen to produce oxyacetylene. Oxyacetylene flame is used to generate light, to weld metals.

Question 238

10._________ gets converted to phosgene, when exposed to sunlight. (A) Chloroform (B) Acetone (C) Benzene (D) Propylene

Answer 238

(A) (SSC CHSL 2016) Exp: Chloroform undergoes oxidation in the presence of light and air to form phosgene (carbonyl chloride) CHCl3 + 1 2 O2 O Cl C Cl || - - + HCl Chloroform is stored in dark bottles to prevent the formation of phosgene, as it is highly poisonous.

Question 239

11.Who discovered benzene? (A) Hal Anger (B) Michael Faraday (C) Bruce Ames (D) Nicolas Appert

Answer 239

(B) (SSC CHSL 2016) Exp: Benzene (phene), C6H6 was first discovered by Michael Faraday (1825).

Question 240

12.What is wood spirit? (A) Methyl Alcohol (B) Ethyl Alcohol (C) Butyl Alcohol (D) Propyl Alcohol

Answer 240

(A) [SSC CHSL 2011] Exp: Methyl Alcohol or Methanol (CH3OH) is known as wood spirit. It is also known as wood alcohol because it was formerly obtained by the destructive distillation of wood.

Question 241

13.The compound that has least value for octane number is- (A) N-Heptane (B) 2-Methyl heptane (C) Iso-octane (D) 2,2-dimethyl Hexane

Answer 241

(A) [SSC CGL Exam, 2014] Exp: The octane number of fuel is based on how two fuels ignite, under compression. Octane no of all fuels lies between n-Heptane and 2,2, 4- Tri Methyl pentane (Iso - octane). Octane number of n-Heptane is zero while isooctane has 100.

Question 242

14.Chloroform can be used as - (A) Analgesic (B) Anaesthetic (C) Antimalarial (D) Antibiotic

Answer 242

(B) [SSC CHSL Exam, 2012] Exp: The first time chloroform was used as anaesthetic by James Simpson. But it is rarely used for this purpose now because it causes extensive liver damage. Chloroform undergoes oxidation in the presence of light and air to form phosgene (carbonyl chloride).

Question 243

15.The process of conversion of sugar into Alcohol is known as- (A) Fermentation (B) Respiration (C) Photosynthesis (D) Excretion

Answer 243

(A) [SSC Steno Exam, 2005] Exp: The process of conversion of sugar into Alcohol (Ethanol) is known as Fermentation. C12H22O11 + H2O Invertase C6H12 O 6+ C6H12O6 (Sucrose) (Glucose) (Fructose) C6H12O6 Zymase 2C2H5OH+2CO2

Question 244

16.Denatured spirit or denatured alcohol is mixed with- (A) Petrol (B) Kerosene (C) Water (D) Pyridine

Answer 244

(D) [SSC Sec off. 2007] Exp: Denaturated spirit or denaturated alcohol is commercial ethyl alcohol to which small amounts of very poisonous substances like pyridine or methyl alcohol has been added.

Question 245

17.The chief source of naphthalene is - (A) Coaltar (B) Diesel (C)Charcoal (D) Camphor

Answer 245

(A) [SSC CHSL 2012] Exp: Naphthalene is the largest single constituent (6 to 10%) of coal tar. Naphthalene as ‘moth ball’ has been used to protect woolen goods from moths.

Question 246

18.Formalin is an aqueous solution of - (A) Methanal (B) Ethanol (C) Fructose (D) Nitric acid

Answer 246

(A) [SSC CGL Exam, 2006] Exp: 40% aqueous solution of formaldehyde (Methanal) is known as formalin. It is used as germicide, antiseptic and also for preserving biological specimens.

Question 247

19.Isomer of ethyl alcohol is - (A) Dimethyl ether (B) Diethyl ether (C) Acetone (D) Methylethyl ether.

Answer 247

(A) [SSC MTS 2006] Exp: Isomer of ethyl alcohol (C2H5OH) is dimethyl ether (CH3OCH3). Isomers are the compounds having same molecular formula but differ from each other in physical or chemical properties.

Question 248

20.Fermentation of starch gives - (A) Ethanol (B) Ethanal (C) Methanal (D) Methanol

Answer 248

(A) [SSC MTS 2006] Exp: Ethanol is obtained from the fermentation of starch. The process of conversion of starch, sugar to alcoholic products (Beer, Whisky and vodka etc.) in the presence of yeast or some bacteria is known as fermentation.

Question 249

21.Which one of the following is a Heterocyclic compound? (A) Benzene (B) Anthracene (C) Naphthalene (D) Furan

Answer 249

(D) [SSC CHSL 2013] Exp: Furan is a heterocyclic compound. Heterocycliccompounds are those cyclic compounds in which one or more of the ring carbons are replaced by another atom (hetero atom). Nitrogen, oxygen and sulphur are most common hetero atoms. eg. pyrrole, thiophene, pyridine, tetrahydrofuran etc.

Question 250

22.Bagasse is used in the manufacturing of- (A) Paper (B) Plastic (C) Paint (D) Varnish

Answer 250

(A) [SSC FCI 2012] Exp: Bagasse is sugarcane fibre waste left after juice extraction. It is used for production of paper.

Question 251

23.Aluminium carbide (Al4C3) on hydrolysis gives- (A) CH4 (B) C2H6 (C) C2H4 (D) C2H2

Answer 251

(A) Exp: Upon hydrolysis, Aluminium carbide gives methane gas. Al4C3 + 12H2O 3CH4+ 4Al(OH)3

Question 252

24.Which of the following gas is used for the artificial ripening of Fruits? Or Which gas is used for the artificial ripening of Green Fruits? (A) Ethyne (B) Ethylene (C) Ethane (D) Methane

Answer 252

(B) [SSC CPO, CGL 2005, 06, 08] Exp: Ethylene gas is used for the artificial ripening of fruits. It is only gaseous plant hormone.

Question 253

25.Ethanol containing 5% water is known as (A) Rectified spirit (B) Absolute alcohol (C) dilute alcohol (D) Power alchol

Answer 253

(A) Exp: Rectified spirit contains 95.6% of ethanol and 4.4% of H2O. It is purified by the means of repeated distillation called rectification.

Question 254

26.Which of the following is used as a test for aliphatic primary amines? (A) Pollen’s test (B) Fehling’s test (C) Isocyanide test (D) Azodye test

Answer 254

(C) Exp: On warming with chloroform and alcoholic solution of KOH, primary amines (both aliphatic and aromatic) form isocyanides or carbylamines with extremely unpleasant smell. 3 R - NH - 3 3 2 2 CHCl KOH R NC KCl H O

Question 255

27.The gas that usually cause explosion in coal mines is- (A) Hydrogen (B) Carbon Monoxide (C) Air (D) Methane

Answer 255

(D) [SSC CHSL 2010] Exp: The gas that usually cause explosion in coal mines is methane (CH4). The coal miners call it fire damp because it forms explosive mixture with air.

Question 256

28.The temperature of oxy-acetylene flame is around- (A) 2800ºC (B) 3200ºC (C) 4000ºC (D) 1500ºC

Answer 256

(B) [SSC CGL 2011] Exp: Acetylene burns in an atmosphere of pure oxygen to produce extremely high temperature (3200°C). This flame is used for welding.

Question 257

29.The correct order of increasing basic strength in aqueous solutions is (A) NH3 < CH3NH2 < (CH3) 2NH (B) CH3NH2 < (CH3)NH < NH3 (C) CH3NH2 < NH3 < (CH3) 2 NH (D) (CH3) 2NH < NH3< CH3NH2

Answer 257

(A) Exp: Order of basic strength in aqueous solution depends not only upon electron releasing effect but also upon steric effect & Hydration effect.

Question 258

30.Production of alcohol from organic compounds by micro-organism is known as- (A) Anaerobic respiration (B) Aerobic respiration (C) Combustion (D)Fermentation

Answer 258

(D) [SSC CHSL 2012] Exp: The process of conversion of carbon compounds (Organic) in alcohol by Micro organism is called fermentation.

Question 259

31.The pair of compounds used as anaesthetic in medicine is- (A) Nitrous oxide, Chloroform (B) Chloroform and Nitrogen Dioxide (C) Nitrogen Dioxide and ether (D) Ether and Ammonia

Answer 259

(A) [SSC CGL 2014] Exp: Nitrous oxide (N2O) & Chloroform (CHCl3) are used as anaesthetic in medicines. Note: Ether (Diethyl ether) is also used as anaesthetic.

Question 260

32.Which one of the following is the constituent of teargas? (A) Ethane (B) Ether (C) Ethanol (D) Chloropicrin

Answer 260

(D) Exp: Chloropicrin (CCl3NO2) or Nitrochloroform is the constituent of tear gas. It is currently used as fungicide, herbicide insecticide and broad spectrum antibiotics.

Question 261

33.Chemical name of Gammahexane is- (A) Toluene (B) Chlorobenzene (C) Aniline (D) Benzene Hexa Chloride

Answer 261

(D) [SSC CPO 2015] Exp: Benzene reacts with chlorine in the presence of ultraviolet light to form benzenehexachloride (BHC). BHC is a powerful insecticide. It is sold under the name Lindane.

Question 262

34.Which of the following known as ‘Marsh gas’? (A) CO (B) CO2 (C) CH4 (D) H2

Answer 262

(C) Exp: CH4 (Methane) is known as Marsh gas because it evolves as bubbles from marshy land by decaying of animals and plant materials.

Question 263

35.What is Baeyer’s reagent? (A) Bromine water (B) Acidic Potassium Permanganate (C) Hydrogen peroxide (D) Alkaline Potassium Permanganate

Answer 263

(D) [SSC MTS 2013] Exp: 1% cold Alkaline potassium permanganate solution (KMnO4) is known as Baeyer’s reagent.

Question 264

36.Which one of the following reacts with Fehling’s solution? (A) HCHO (B) C2H5OH (C) CH3COOH (D) CH3COCH3

Answer 264

(A) [SSC MTS 2014] Exp: Carbon compounds of Aldehyde group reacts with Fehling’s solution and HCHO is a compound of Aldehyde group.

Question 265

37.The most extensive use of molasses after fermentation is to produce (A) Methanol (B) Sugar (C) Ethanol (D) Sugarcane

Answer 265

(C) (SSC CGL 2016) Exp: Molasses is a cheap source of glucose, fructose, and sucrose and it forms an excellent raw material for making ethyl alcohol. Today less than 10% of ethyl alcohol is made by this method. In India, molasses is still major source of ethyl alcohol.

Question 266

38.Which organism is responsible for alcohol fermentation? (A) Chlorella (B) Yeast (C) Agaricus (D) Puccinia

Answer 266

(B) (SSC CGL 2016) Exp: Yeast cells convert sugar solution into alcohol by fermentation. Invertase and zymase enzymes participate in this process. C12H22O11+H2O Invertase C6H12O6+C6H12O6 (Glucose) (Fructose) C6H12O6 Zymase 2C2H5OH+2CO2 Glucose Ethyl alcohol

Question 267

39.During fermentation of sugar, the compound which is always formed is (A) Methyl Alcohol (B) Ethyl Alcohol (C) Acetic Acid (D) Ethylene

Answer 267

(B) (SSC CGL 2016) Exp: During fermentation of sugar ethyl alcohol (ethanol) is always formed. Fermentation of sugar takes place in presence of yeast cells.

Question 268

40.What are Aldehydes? (A) Mild oxidising agents (B) Strong oxidising agents (C) Strong reducing agents (D) Mild reducing agents

Answer 268

(C) (SSC CGL 2016) Exp: Aldehydes are easily oxidised to corresponding acids with same no of carbon atoms with the help of oxidising agents such as acidified KMnO4 or acidified K2Cr2O7 solution. Reducing agents are easily oxidised itself and reduce other substances. Example. CH3CHO+|O| CH3COOH C6H5CHO + |O| C6H5COOH Since Aldehydes can be easily oxidized, they act as strong reducing agents.

Question 269

41.A lcoho l obtained by the process of Saponification is - (A) Ethyl alcohol (B) Methyl alcohol (C) Wood spirit (D) Glycerol

Answer 269

(D) [SSC CHSL 2013] Exp: Glycerol is obtained from the process of Saponification it’s a kind of sugar alcohol. Triglyceride+Sodium hydroxide Glycerol+3 Soap molecules

Question 270

42.Which of the following is also known as Carbolic Acid? (A) Phenol (B) Hydroxide (C) Sulphuric Acid (D) Ethanol

Answer 270

(A) (SSC CGL 2017) Exp: Phenol is also known as Carbolic acid. Its molecular formula is C6H5OH. It is used as anti-microbial agent.

Question 271

1._______ fibre is used in making bulletproof vests. (A) Nylon-66 (B) Terylene (C) Kevlar (D) Lexan

Answer 271

(C) (SSC CHSL 2016) Exp: Kevlar is a polyamide which is used to make bulletproof vests. 1,4-diaminobenzene and terephthaloyl chloride react to form kevlar.

Question 272

2.What is the full form of PVC? (A) Phosphonil vinyl Carbonate (B) Polyvinyl S Carbonate (C) Polyvinyl Carbonate (D) Polyvinyl Chloride

Answer 272

(D) (SSC CHSL 2016) Exp: Polyvinyl chloride (PVC) is polymerised product of vinyl chloride in the presence of benzoyl peroxide. PVC is a thermoplastic polymer. It is used for artificial floor covering.

Question 273

3.Which fibre is used for making bristles of brushes. (A) Kevlar (B) Nylon-66 (C) Terylene (D) Lexan

Answer 273

(B) (SSC CHSL 2016) Exp: Nylon-66 is used for making bristles of brushes. It is a polymerised product (polyamides) of adipic acid and hexamethylene diamine.

Question 274

4.Which among the following is false about natural rubber? (A) It is an elastomer (B) It is a monomer of cis-isoprene (C) Natural rubber is a polymer of chloroprene (D) It is heated with sulphur compounds to improve its properties

Answer 274

(C) (SSC CHSL 2016) Exp: Natural rubber may be considered as a linear polymer of Isoprene (2-methyl-1, 3 butadiene). Natural rubber possesses elastic properties so, it is also termed as Elastomer. To improve physical properties a process of vulcanisation is carried out. This process consist of heating a mixture of raw rubber with sulphur and additive.

Question 275

5.Which of the following is a Synthetic rubber? (A) Leoprene (B) Monoprene (C) Neoprene (D) Isoprene

Answer 275

(C) (SSC CHSL 2016) Exp: In the given options, Neoprene is a synthetic rubber. Neoprene or polychloroprene is polymer of chloroprene.

Question 276

6.Milbemycin is used in the eradication of _____. (A) Agricultural Fungus (B) Agricultural Pests (C) Agricultural Herbs (D) Agricultural Weeds

Answer 276

(B) (SSC CHSL 2016) Exp: Milbemycin is used as broad spectrum antiparasite. It is used in the eradication of agricultural pests.

Question 277

7.Plastic bottles are made of a polymer called PET. The expanded form of PET is (A) Polyethylene terephthalate (B) Polyethyl terelene (C) Polyethylene triphosphate (D) Polyethyl tetrachloride

Answer 277

(A) (SSC CHSL 2016) Exp: The expanded form of PET or PETE is Polyethylene terephthalate. Its commercial name is Terylene. It is also used for making clothes and helmets.

Question 278

8.In chemistry, soap is a salt of a ____. (A) Fatty acid (B) Glycol (C) Phosphorous (D) Ammounium Carbonate

Answer 278

(A) (SSC CHSL 2016) Exp: Saponification is a process that produces soap. In chemistry, soaps are sodium or potassium salts of higher fatty acids like stearic acid, palmitic acid, Oleic acid etc.

Question 279

9.The brand name Teflon represents which polymer? (A) Polystyrene (B) Polypropylene (C) Polytetrafluoroethylene (D) Polyethylene terephthalate

Answer 279

(C) (SSC CHSL 2016) Exp: Teflon represents polytetrafluoro ethylene (PTFE). It is a polymer of Tetrafluoro ethylene. It is used for making nonstick cooking utensils.

Question 280

10.Which is widely used in the plastic industry for manufacturing Bakelite? (A) Ethyl Alcohol (B) Phenol (C) Ortho-Cresol (D) Catechol

Answer 280

(B) [SSC See off. 2006] Exp: Bakelite is formed by condensation reaction of urea & formaldehyde. It is a thermosetting polymer (the polymer which becomes hard on heating).

Question 281

11.Which of the following is used as raw material for the manufacture of rayon? (A) Coal (B) Petroleum (C) Cellulose (D) Plastic

Answer 281

(C)Exp: Cellulose diacetate is also known as Rayon. It is obtained by the acylation of cellulose (natural polymer) with acetic anhydride in the presence of sulphuric acid. It is a semi synthetic polymer. Semisynthetic polymers are obtained from natural polymers by subjecting them to some chemical process.

Question 282

12.Barbituric acid and its derivatives are well known as- (A) Tranquilizers (B) Antiseptics (C) Antibiotics (D) Antipyretics

Answer 282

(A) Exp: Barbituric acid and its derivatives are well known as Tranquilizers (medical drug, which reduce tension or anxiety).

Question 283

13.The helical structure of protein is stabilized by(A) Dipeptide bonds (B) Hydrogen bonds (C) Ester bonds (D) Peptide bonds

Answer 283

(B) Exp: The helical structure of proteins has been confirmed by X-rays diffraction. In the helix structure, NH group of one unit is linked to CO group by hydrogen bonding. The hydrogen bonds hold the helix in position.

Question 284

14.The sugar which is not a disaccharide (A) Lactose (B) Galactose (C) Sucrose (D) Maltose

Answer 284

(B) Exp: Galactose (C6H12O6) is a monosaccharide. Monosaccharide have general formula (CnH2nOn). In monosaccharides, ratio of carbon, hydrogen and oxygen is 1: 2: 1. Disaccharide gives two molecules of monosaccharide on hydrolysis.

Question 285

15.Which one of the following is non-reducing sugar? (A) Glucose (B) Sucrose (C) Maltose (D) Lactose

Answer 285

(B) Exp: Saccharides which reduce fehling solution, Tollen’s reagent or Benedict’s solution are called reducing sugars while those which fail to respond to those reactions are termed as non reducing sugars. ex: Sucrose, Starch, Cellulose, Glycogen

Question 286

16.Which of the following is a biodegradable polymer? (A) Cellulose (B) Polythene (C) Polyvinyl chloride (D) Nylon-6

Answer 286

(A) Exp: The biodegradable polymer are the polymers which are degraded by the micro-organisms within a suitable period of time. Ex: Polyglycolic acid (PGA), polyhydroxy butyrate (PHB).

Question 287

17.Which of the following is related to the discovery of Nylon? (A) Louis Pasteur (B) John Cabot (C) J. Nicephore Niepce (D) Dr. Wallace H. Carothers

Answer 287

(D) [SSC MTS 2008] Exp: Nylon was discovered by American chemist Dr. wallac H. Carothers in 1935. Nylon is the material used in parachutes.

Question 288

18.PVC is obtained by the polymerization of - (A) Propane (B) Vinyl chloride (C) Styrene (D) Acetylene

Answer 288

(B) [SSC CPO 2012] Exp: PVC (Polyvinyl Chloride) is formed by the polymerization of vinyl chloride. It is a homopolymer. It is used for making rain coats, water pipes and hand bags.

Question 289

19.Polyethene is formed by - (A) Ethylene (B) Propylene (C) Acetylene (D) Annulene

Answer 289

(A) [SSC Sec. officer 2006] Exp: Polyethene (Polythene) is a polymer of ethylene. It is a thermoplastic.

Question 290

20.Which one of the following is a Natural Polymer? (A) Bakelite (B) Cellulose (C) PVC (D) Nylon

Answer 290

(B) Exp: Cellulose is a natural polymer. It is a polymer of glucose. Some other natural polymers are protein, silk, nucleic acid, rubber, polysaccharides.

Question 291

21.G lycogen, Cellu lose and starch are the polymers of- (A) Fructose (B) Glucose (C) Lactose (D) Maltose

Answer 291

(B) [SSC CGL 2012] Exp: Glycogen, cellulose and starch are the polymers of glucose. All are polysaccharides.

Question 292

22.Which of the following element is used for vulcanisation of rubber? (A) Sulphur (B) Bromine (C) Silicon (D) Phosphorous

Answer 292

(A) Exp: Sulphur element is used for vulcanization of the rubber. On vulcanisation, sulphur forms cross links at the reactive sites of double bonds and thus the rubber gets stiffened. 5% of sulphur is used for manufacturing of rubber tyres.

Question 293

23.The process of heating of Rubber with sulphur to increase its quality is known as- (A) Vulcanisation (B) Acceleration (C) Galvanization (D) Sulphonation

Answer 293

(A) [SSC CGL Exam, 2014] Exp: The process of heating of rubber with sulphur between 373K to 415K to increase it quality is known as Vulcanisation.

Question 294

24.Natural rubber is a polymer of- (A) Isoprene (B) Ethylene (C) Styrene (D) Butadiene

Answer 294

(A) [SSC MTS 2011, SSC CGL 2006] Exp: Natural rubber is a polymer of Isoprene (2- methyl - 1, 3- butadiene). All the double bonds in rubber are cis, hence natural rubber is cis-polyisoprene. Main source of rubber is Hevea brasiliensis tree.

Question 295

25.Bakelite is a polymer of Phenol and (A) Formaldehyde (B) Acetaldehyde (C) Benzaldehyde (D) Cinnamaldehyde

Answer 295

(A) [SSC Steno 2011] Exp: Bakelite are polymers of phenol and formaldehyde. It is a cross linked polymer. It is used for making combs electrical switches, handles of various utensils etc.

Question 296

26.Which one of the following is a synthetic polymer? (A) Silk (B) Protein (C) Polystyrene (D) Starch

Answer 296

(C) [SSC LDC Exam, 2005] Exp: Polystyrene is a synthetic polymer. It is a polymer of styrene. It is a thermosplastic polymer. It is used for making toys, radio & T.V. cabinets, wrapping material.

Question 297

27.Which among the following is a petroleum wax? (A) Honey Wax (B) Paraffin Wax (C) Jojoba Wax (D) Carnauba Wax

Answer 297

(B) [SSC CGL Exam, 2005] Exp: Paraffin wax is known as petroleum wax. It is a mixture of higher hydrocarbons. It is obtained from petroleum, coal or oil shale. Honey wax is obtained from honey bee. Carnauba also called Brazil wax and palm wax is obtained from palm leaves.

Question 298

28.Wax used for making candles is chemically a mixture of- (A) Aliphatic Hydrocarbons (B) Aromatic Hydrocarbons (C) Cyclic Hydrocarbons (D) Aliphatic and Aromatic Hydrocarbons

Answer 298

(A) [SSC Tax Asst. 2008] Exp: Wax used for making candles is chemically a mixture of aliphatic hydrocarbons.

Question 299

29.Petroleum is a Mixture of - (A) Carbohydrates (B) Carbonates (C) Hydrocarbons (D) Carbides

Answer 299

(C) [SSC CPO 2007] Exp: Petroleum is a mixture made up of mostly hydrocarbons. It consists alkanes (37-70%), cycloalkanes (16-64%) and aromatic hydrocarbons (8-15%). Its unpleasent odour is due to sulphur compounds.

Question 300

30.Which of the following could be used as fuel in propellant of Rockets? (A) Liquid Hydrogen + Liquid Nitrogen (B) Liquid Oxygen + Liquid Argon (C) Liquid Nitrogen + Liquid oxygen (D) Liquid Hydrogen + Liquid oxygen

Answer 300

(D) [SSC CGL 2011] Exp: A mixture of liquid hydrogen and liquid oxygen is used as a fuel in rockets.

Question 301

31.Glycol is added to aviation gasoline because it- (A) Prevents freezing of petrol (B) Reduces consumption of petrol (C) Reduces evaporation of petrol (D) Increase efficiency of petrol

Answer 301

(A) [SSC CGL 2011] Exp: Glycol is also called Ethylene Glycol, it is a dihydric alcohol. It is added to aviation gasoline because it prevents freezing of petrol. It can be used as an antifreeze compound in car radiators.

Question 302

32.Aqueous Hydrolysis of sucrose formed - (A) Only Lactose (B) Only Glucose (C) Glucose and Fructose (D) Glucose and Lactose

Answer 302

(C) [SSC MTS 2006] Exp: In the presence of enzyme invertase, Sucrose is converted into glucose and fructose by aqueous hydrolysis. Sucrose (C12H22O11) is a disaccharide sugar. It is known as sugar of sugarcane.

Question 303

33.Glucose is a type of - (A) Pentose Sugar (B) Hexose Sugar (C) Tetrose Sugar (D) Diose Sugar

Answer 303

(B) [SSC CHSL 2014] Exp: Glucose is a type of Hexose sugar. Its chemical formula is C6H12O6.

Question 304

34.The class of drugs used for the treatment of stress is or The drug which lowers anxiety and provide peace (A) Tranquilizer (B) Diuretics (C) Pain killer (D) Antihistamine

Answer 304

(A) [SSC CGL 2012] Exp: Tranquilizers are used for the treatment of stress and mild or even severe mental disease. They form an essential component of sleeping pills.

Question 305

35.The branch of medicine involving synthetic chemical compounds is- (A) Allopathic (B) Homeopathy (C) Unani (D) Ayurveda

Answer 305

(A) [SSC CGL 2014] Exp: Allopathy is a medical practice which involves the treatment of diseases by using synthetic drug or chemicals.

Question 306

36.Zinc Phosphide is commonly used as -(A) Fungicide (B) Herbicide (C) Rodenticide (D) None of these

Answer 306

(C)Exp: The substance which is used to kill rat is called rodenticide. Examples:- Zinc phosphide, Thallium sulphate, Sodium monochloroacetate, Sodium fluoroacetate.

Question 307

37.Which of the following gas is used to destroy the microbes? (A) Chlorine (B) Oxygen (C) Hydrogen (D) Neon

Answer 307

(A) [SSC Steno 2005] Exp: Chlorine in the concentration of 0.2 to 0.4 ppm in aqueous solution is disinfectant. Chlorine destroys the microbes present in water

Question 308

38.Substance which are used as a food preservative- (A) Sodium carbonate (B) Tartaric acid (C) Acetic acid (D) Sodium salts of benzoic acids

Answer 308

(D) [SSC Tax Asst., MTS 2002, 06 & 08] Exp: Food preservatives prevent spoilage of food due to microbial growth. Eg:- Sodium benzoate

Question 309

39.Which gas is used as a disinfectant in drinking water? (A) Hydrogen (B) Oxygen (C) Fluorine (D) Chlorine

Answer 309

(D) [SSC CGL 2006] Exp: Disinfectant are substances which are applied on the surface of non-living objects to destroy microbes. Chlorine in the concentration of 0.2 to 0.4 ppm in aqueous solution acts as disinfectant. Chlorine destroy the microbes present in water.

Question 310

40.Match the following- A. Copper 1. Fertilizer Sulphate B. Penicillin 2. Insecticide C. Urea 3. Antifungal D. Malathion 4. Antibiotic A B C D (A) 1 2 3 4 (B) 2 4 1 3 (C) 3 4 1 2 (D) 4 3 2 1

Answer 310

(C) [SSC CPO 2012] Exp: Coppersulphate (CuSO4) - Antifungal Urea (NH2CONH2) - Fertilizer Penicillin - Antibiotic Malathion - Insecticide

Question 311

41.’Saponification’ is a process by which- (A) Soap is prepared (B) Sulphur is extracted (C) Plastic is prepared (D) Protein is identified.

Answer 311

(A) [SSC CHSL 2012] Exp: Saponification is the alkaline hydrolysis of the fatty acid esters. Example: The chemical reaction between fatty acid and sodium hydroxide is a saponification reaction. Triglyceride + Sodium hydroxide Glycerol + 3 soap molecules.

Question 312

42.What is the by Product obtained in soap industry? (A) Caustic soda (B) Glycerol (C) Caustic Potash (D) Naphthalene

Answer 312

(B) [SSC Sec. off. - 2006] Exp: NaOH (Sodium Hydroxide) is a white solid crystal. Its aqueous solution is smooth as same as soap. It is also known as caustic soda. It is also used in the manufacturing of soap. Hydrolysis of fatty acids with caustic soda forms soap and glycerol and this process is known as ‘Saponification’.

Question 313

43.The process involved in the making of soap is- (A) Saponification (B) Hydrolysis (C) Polymerization (D) Liquification

Answer 313

(A) [SSC CPO 2008] Exp: Saponification is the alkaline hydrolysis of the fatty acid esters. Example: The chemical reaction between fatty and sodium hydroxide is a saponification reaction. Triglyceride + Sodium hydroxide Glycerol + 3 soap molecules.

Question 314

44.Glycol is used to manufacture which of the following? (A) Nylon (B) Artificial silk (C) Terylene (D) Rubber

Answer 314

(C) (SSC CGL 2016) Exp: Glycol (Ethylene glycol) and Terephthalic acid form condensation product is called Terylene or Dacron.

Question 315

45.Which of the following is used as non-stick coating for cooking utensils? (A) Perspex (B) Styrofoam (C) Polystyrene (D) Teflon

Answer 315

(D) (SSC CGL 2016) Exp: Teflon or Polytetrafluoro ethylene (PTFE) is prepared by the polymerisation of tetrafluoro ethylene in the presence of benzoyl peroxide. It is used for making nonstick surfaces of cooking p At high temperature (573K) it may crack.

Question 316

46.The antiseptic compound present in Dettol is- (A) Iodine (B) Cresol (C) Biothional (D) Enloroxylenol

Answer 316

(D) [SSC CGL 2013] Exp: Dettol contains the antiseptic compound enloroxylenol. Dettol is a mixture of chloroxylenol and terpineol dissolved in a suitable solvent.

Question 317

47.KMnO4 can be used as - (A) Fertilizer (B) Insecticide (C) Disinfectant (D) Pesticide

Answer 317

(C)Exp: KMnO4 (Potassium Permanganate) can be used as a disinfectant (germicide).It is used to purify well water. It is commonly known as Red Medicine or Lal dawa.

Question 318

48.Tincture of iodine is a solution of Iodine in - (A) Potassium iodide (B) Ethyl alcohol (C) Water (D) Sodium chloride

Answer 318

(A) [SSC Tax Asst. 2006] Exp: Tincture of iodine or Iodine tincture is an antiseptic. 2 - 7% elemental iodine along with potassium iodide or sodium iodide dissolved in mixture of ethanol & water.

Question 319

49.Terylene is a condensation polymer of ethylene glycol and which acid? (A) Benzoic Acid (B) Salicylic acid (C) Phthalic acid (D) Terephthalic acid

Answer 319

(D) (SSC CGL 2016) Exp: Terylene is also known as Dacron and it is the condensation product of ethylene glycol and terephthalic Acid. Terylene is used in the manufacture of terycot, terywool & terysilk, magnetic recording tapes, conveyer belts, aprons for industrial workers.

Question 320

50.Which of the following fibres is considered as the strongest natural fibre? (A) Cotton (B) Jute (C) Wool (D) Silk

Answer 320

(D) (SSC CGL 2016) Exp: Silk is natural protein fibre, made by silkworm. It is one of the strongest natural fibres. The rearing of silkworm is known as Sericulture.

Question 321

51.Which of the following is a natural polymer? (A) Bakelite (B) Nylon (C) Polythene (D) Starch

Answer 321

(D) (SSC CGL 2016) Exp: Natural polymers occur in nature mostly in plants and animals. Examples - Starch, cellulose, proteins natural rubber, nucleic acids etc.

Question 322

52.Synthetic detergents are prepared from (A) Potassium salts of higher fatty-acids (B) Sodium salts of higher fatty-acids (C) Hydrocarbons of petroleum (D) Glycerides

Answer 322

(C) (SSC CGL 2016) Exp: Synthetic detergents are normally prepared from petrochemicals, fats and oils.

Question 323

53.Which of the following gas is used in bulb? (A) Hydrogen (B) Carbon-dioxide (C) Carbon monoxide (D) Argon

Answer 323

(D) (SSC CPO 2017) Exp: Argon gas is used in bulbs because argon is an inert gas & doesn’t react even at higher temperatures.

Question 324

54.Chlorine gas is a major component of which of the following? (A) Water (B) Tear gas (C) Liquified Petroleum Gas (D) Gobar gas

Answer 324

(B) (SSC CPO 2017) Exp: Chemical formula of Tear gas is C10H5ClN2. So, chlorine is component of tear gas LPG is a mixture of flammable hydrocarbon gases including propane & butane while Gobar gas mainly consists of methane.

Question 325

55.In which of the following silicon is not used? (A) Solar Panels (B) IC manufacturing (C) Optical glass (D) Ink pen

Answer 325

(D) (SSC CPO 2017) Exp: Silicon is used in solar panels, optical glass & IC chips as silicon is a semi-conductor. But in ink, silicon is not present.

Question 326

56.Which among the following is used in fire extinguisher? I. Carbon dioxide II. Oxygen III. Sulphur dioxide (A) Only I (B) Only II (C) Only III (D) All options are correct.

Answer 326

(A) (SSC CPO 2017) Exp: Fire Extinguishers are the devices which are used to control fire. From the given options, Carbon dioxide is used in fire extinguisher.

Question 327

57.Bleaching action of Chlorine is due to which reaction? (A) Oxidation (B) Hydrolysis (C) Redox (D) Decomposition

Answer 327

(A) (SSC CPO 2017) Exp: Chlorine on reaction with water releases nascent Oxygen. Cl2 + H2O HCl + HOCl HOCl HCl + [O] This nascent oxygen reacts with coloured matter to make it colourless. Coloured matter + [O] Colourless matter + H2O. Thus, chlorine has its bleaching action due to Oxidation phenomenon.

Question 328

58.Which of the following is used for ripening of fruits? (A) Methylene (B) Ethylene (C) Acetone (D) Methane

Answer 328

(B) (SSC CPO 2017) Exp: Ethylene is a gaseous plant hormone. It is used for ripening of fruits. Ethylene is also called as ethene (CH2 = CH2).

Question 329

59.What is the major component of Gobar Gas? (A) Propane (B) Butane (C) Methane (D) Ethylene

Answer 329

(C) (SSC CPO 2017) Exp: Biogas is produced from cattle dung in a biogas plant i.e. commonly known as Gobar Gas. Gobar gas mainly consists of Methane (CH4).

Question 330

60.Rock Salt contains which mineral? (A) Gypsum (B) Sodium (C) Potassium (D) Magnesium

Answer 330

(B) (SSC CPO 2017) Exp: Rock salt is Sodium Chloride (NaCl). So, Rock salt contains sodium mineral.

Question 331

61.Which of the following elements are commonly found in most fertilizers? (A) Sodium, Potassium, Phosphorous (B) Sodium, Potassium, Calcium (C) Nitrogen, Potassium, Phosphorous (D) Nitrogen, Potassium, Calcium

Answer 331

(C) (SSC CPO 2017) Exp: Fertilizers are the substance which are added to soil to improve its nutrient quality (fertility). Nitrogen (N), Potassium (K) & Phosphorous (P) are the main three constituents of fertilizers. Therefore, they are called as NPK fertilizers

Question 332

62.What is a Vermicompost? (A) Organic fertilizer (B) Inorganic fertilizer (C) Toxic Substance (D) Type of soil

Answer 332

(A) (SSC CPO 2017) Exp: Formation of compost by using earth worms (Red Earth worms) is called as Vermicompost. It is a organic Manure or organic fertilizer.

Question 333

63.What is dry ice? (A) Solid Carbon dioxide (B) Solid Nitrogen dioxide (C) Solid Sulphur dioxide (D) Solid Water

Answer 333

(A) (SSC CGL 2017) Exp: Dry ice is solid CO2. At atmospheric pressure solid CO2 is converted directly into vapour without a liquid phase

Question 334

64.PET is a very familiar form of _____________. It is used for making bottles. (A) Nylon (B) Acrylic (C) Polyester (D) Rayon

Answer 334

(C) (SSC CGL 2017) Exp: PET refers to polyethylene terephthalate. It is a thermoplastic polymer. It is a condensation polymer of terephthalic acid & ethylene glycol. PET is used for making bottles, synthetic fibres and coating etc.

Question 335

65.Which acid is released when an ant bites? (A) Hydrochloric Acid (B) Formic Acid (C) Acetic Acid (D) Phosphoric Acid

Answer 335

(B) (SSC CGL 2017) Exp: Formic acid or Methanoic acid (HCOOH) is released when a red ant bites.

Question 336

66.Which of the following metal shown by its symbol is generally used for making filaments of bulb? (A) Fe (B) An (C) Ag (D) W

Answer 336

(D) (SSC CGL 2017) Exp: Tungsten is generally used for making filaments of bulb because it has very high melting point (3422oC). Symbol of tungsten is W.

Question 337

67.In which industry Potassium nitrate is used commercially? (A) Glass manufacturing (B) Electroplating (C) Fire cracker manufacturing (D) Leather industry

Answer 337

(C) (SSC CGL 2017) Exp: Potassium nitrate is used for manufacturing the fire crackers because it is a good oxidant. It helps in oxidation of fire work mixture.

Question 338

68.Which among the following is used to treat Indigestion? (A) Antacid (B) Antiseptic (C) Analgesic (D) Antibiotic

Answer 338

(A) (SSC CGL 2017) Exp: Antacids are basic substances which neutralise the stomach acidity on ingestion. They are used to treat Indigestion. eg:- Mg(OH)2

Question 339

69.Which base is present in soap? (A) Sodium hydroxide (B) Silicon dioxide (C) Calcium hydroxide (D) Ammonium hydroxide

Answer 339

(A) (SSC CGL 2017) Exp: Sodium hydroxide is found in soaps. Soaps are formed by reacting a base with fatty acid. Sodium hydroxide + Glycerol Tristearate Sodium stearate (soap) + Glycerol

Question 340

70.Which fibre is also called as artificial silk?(A) Nylon (B) Rayon (C) Polyester (D) Acrylic

Answer 340

(B) (SSC CGL 2017) Exp: Rayon is also known as Artificial silk because it resembles silk. Rayon is a synthetic fibre. It is cheaper than silk. Rayon is used for making fibres, clothes etc.

Question 341

71.Fire extinguishers emit which gas? (A) Carbon monoxide (B) Chlorine (C) Carbon dioxide (D) Nitrogen

Answer 341

(C)Exp: Fire extinguishers are used to stop the fire. From the given options, fire extinguishers contain CO2, i.e. heavier than oxygen which stops fire.

Question 342

72.___________ is obtained by evaporation of sea. (A) Sugar (B) Iron (C) Salt (D) Steel

Answer 342

(C) (SSC CGL 2017) Exp: Salt is obtained by evaporation of seawater as seawater contains sodium chloride, magnesium chloride etc.

Question 343

73.The rubbing surface of a matchbox has powdered glass and a little red ________________. (A) Antimony (B) Arsenic (C) Silicon (D) Phosphorous

Answer 343

(D) (SSC CGL 2017) Exp: Friction between match box surface & match stick lights up fire. Tip of match has potassium chlorate (an oxidant), sulphur, starch & glue. Striking surface has red phosphorous.

Question 344

74.A __________ thread is actually stronger than a steel wire. (A) Wool (B) Cotton (C) Jute (D) Nylon

Answer 344

(D) (SSC CGL 2017) Exp: A nylon thread is actually stronger than a steel wire because nylon thread can support more weight compared to steel wire of same thickness.

Question 345

75.Fabric made from_________ does not get wrinkled easily. (A) Cotton (B) Flax (C) Silk (D) Polyester

Answer 345

(D) (SSC CGL 2017) Exp: Fabric made from polyester does not get wrinkled easily because it has high wrinkle resistant.

Question 346

1.Ozone hole is caused by chemicals like _____. (A) Nitrogen oxide (B) Hydrogen sulphide (C) Chlorofluoro carbon (D) Carbon monoxide

Answer 346

(C) (SSC CHSL 2016) Exp: Chlorofluorocarbon and nitric oxide have been found to be the most responsible for depletion of ozone and creating ozone hole. Ozone hole was discovered in 1984 by British Antarctic survey scientist, Joseph Farman, Brain Gardiner and Jonathan shanklin.

Question 347

2.The poisonous gas accidentally released in Bhopal Gas Tragedy is (A) Methane (B) Nitrous Oxide (C) Methyl Isocyanate (D) Cyanogen

Answer 347

(C) (SSC CHSL 2016) Exp: Bhopal gas tragedy was caused by (MIC) methyl isocyanate (CH3NCO) on december 2, 1984 in Bhopal (M.P) in the Union Carbide factory. MIC is used for manufacturing the insecticide, Carbaryl.

Question 348

3.The Great Smog of 1952 was a severe air-pollution event which affected _______. (A) Paris (B) London (C) New York (D) Delhi

Answer 348

(B) (SSC CHSL 2016) Exp: The great smog of 1952 was a severe air pollution event which affected London. London smog or classical smog or sulphurous smog:- This type of smog was first observed in London in December 1952 which killed many people. It is formed due to presence of SO2 and humidity in the air which combine to form H2SO4. It is formed in the early morning hours of winter month. smoke + fog = smog

Question 349

4.Which of the following gases is produced due to incomplete combustion of fuel? (A) Carbon dioxide (B) Carbon monoxide (C) Methane (D) Ethane

Answer 349

(B) (SSC CHSL 2016) Exp: Carbon monoxide is formed by incomplete combustion of carbon and carbon containing fuels. 2C + O2 2CO This type of incomplete combustion occurs during burning of petrol or diesel in automobiles therefore CO is always present in automobile exhausts.

Question 350

5.Which of the following is not a green house gas? (A) Carbon dioxide (B) Water vapour (C) Carbon monoxide (D) Nitrous oxide

Answer 350

(C) (SSC CHSL 2016) Exp: Greenhouse gases are: Carbon dioxide (CO2)-60%, Methane (CH4)-20% Chlorofluoro carbon (CFC)-14%, Nitrous oxide (N2O)-6%

Question 351

6.Haemoglobin has the highest affinity with which of the following? (A) SO2 (B) CO2 (C) CO (D) NO2

Answer 351

(C) (SSC CHSL 2016) Exp: Haemoglobin has the highest affinity with CO. CO is able to form a complex with haemoglobin (carboxyhaemoglobin) which is about 300 times more stable than the oxyhaemoglobin.

Question 352

7.Which of the following types of water is known to be absolutely free from any impurity? (A) Mineral Water (B) Distilled Water (C) Spring Water (D) Boiled Water

Answer 352

(B) (SSC CHSL 2016) Exp: Distilled water has no impurity. Distillation is a method of water purification.

Question 353

8.Which rays cause skin damage? (A) X-rays (B) UV rays (C) Infrared rays (D) Yellow rays

Answer 353

(B) (SSC CHSL 2016) Exp: UV rays cause burning or tanning of skin. UV rays damage DNA of skin & cause cancer.

Question 354

9.Which of the following is a greenhouse gas or a gas which can deplete the ozone layer? (A) B2H6 (B) NF3 (C) CCl3F (D) C6H6

Answer 354

(C) (SSC CHSL 2016) Exp: CCl3F is Freon. Freons are the chlorofluorocarbon (CFCs) or hydrochlorofluorocarbons (HCFCs) compounds. They are used as refrigerants and as aerosol propellants. Freons are responsible for Ozone depletion

Question 355

10.The Ozone layer is present in which atmospheric layer? (A) Lithosphere (B) Ionosphere (C) Stratosphere (D) Biosphere

Answer 355

(C) (SSC CHSL 2016) Exp: Stratosphere is a second layer of Earth’s atmosphere, present above troposphere layer.

Question 356

11.Which of the following constitutes highest percentage of Green House gases?(A) Ethane (B) Methane (C) Carbon dioxide (D) Propane

Answer 356

(C) (SSC CHSL 2016) Exp: Greenhouse gases are: Carbon dioxide (CO2)-60%, Methane (CH4)-20% Chlorofluoro carbon (CFC)-14%, Nitrous oxide (N2O)-6%

Question 357

12.Which of the following is a greenhouse gas or a gas which can deplete the ozone layer? (A) Ar (B) HN3 (C) CO2 (D) C4H6

Answer 357

(C) (SSC CHSL 2016) Exp: Water vapour CO2, CH4, N2O, Ozone are Green House Gases which deplete Ozone layer.

Question 358

13.Which of the following is a greenhouse gas or a gas, which can deplete the ozone layer? (A) As (B) Kr (C) C4H8 (D) CH4

Answer 358

(D) (SSC CHSL 2016) Exp: Water vapour CO2, CH4, N2O, Ozone are Green House Gases.

Question 359

14.Which of the following is a greenhouse gas or a gas which can deplete the ozone layer? (A) B2H6 (B) Ne (C) C6H14 (D) O3

Answer 359

(D) (SSC CHSL 2016) Exp: Exp: Water vapour CO2, CH4, N2O, Ozone (O3) are Green House Gases.

Question 360

15.Which of the following is a greenhouse gas or a gas which can deplete the ozone layer? (A) BCl3 (B) Ni(CO)4 (C) CH3OH (D) CClF3

Answer 360

(D) (SSC CHSL 2016) Exp: CClF3 is Freon. freons are the chlorofluorocarbon (CFCs) or hydrochlorofluorocarbons (HCFCs) compounds. They are used as refrigerants and as aerosol propellants. Freons are responsible for Ozone depletion. Water vapour CO2, CH4, N2O, Ozone are Green House Gases.

Question 361

16.Which of the following is a greenhouse gas or gas which can deplete the ozone layer? (A) Br2 (B) OF2 (C) CHCl2F (D) CO

Answer 361

(C) (SSC CHSL 2016) Exp: CHCl2F is Freon. Freons are the chlorofluorocarbon (CFCs) or hydrochlorofluorocarbons (HCFCs) compounds. They are used as refrigerants and as aerosol propellants. Freons deplete Ozone layer.

Question 362

17.The common name of dichlorodifluoromethane is _____. (A) Galena (B) Freon (C) Gypsum (D) Borax

Answer 362

(B) (SSC CHSL 2016) Exp: Freons are the chlorofluorocarbon (CFCs) or hydrochlorofluorocarbons (HCFCs) compounds. They are used as refrigerants and as aerosol propellants. Freons deplete Ozone layer.

Question 363

18.Which of the following is a greenhouse gas or a gas which can deplete the ozone layer? (A) N2O (B) AsH3 (C) N2 (D) C5H12

Answer 363

(A) (SSC CHSL 2016) Exp: Water vapour CO2, CH4, N2O, Ozone are Green House Gases which deplete Ozone layer.

Question 364

19.Air has maximum proportion of which inert gas? (A) Carbon dioxide (B) Nitrous oxide (C) Argon (D) Carbon monoxide

Answer 364

(C) (SSC CHSL 2016) Exp: In the given options, Argon is an inert gas 0.93%. Argon is present in air. CO2 = 0.04%.

Question 365

20.Which of the following is a greenhouse gas or a gas which can deplete the ozone layer? (A) CH2ClF (B) C2H2 (C) PF5 (D) COCl2

Answer 365

(A) (SSC CHSL 2016) Exp: CH2ClF is freon. Freons are the chlorofluorocarbon (CFCs) or hydrochlorofluorocarbons (HCFCs). They are used as refrigerants and as aerosol propellants. Freons are responsible for Ozone depletion

Question 366

21.Methane an air pollutant is produced ______. (A) By action of ultraviolet light on nitrogenous compounds. (B) As a by-product of manufacturing ammonical fertilizers (C) By burning of coal in insufficient air (D) By digestion of food by animals

Answer 366

(D) (SSC CHSL 2016) Exp: Methane (CH4) is the simplest hydrocarbon. It is released into the air in large quantities by the anaerobic decomposition of organic matter in soil, water and sediments. Bacteria 2CH O CH CO 2 4 2 Domestic animals contribute a very huge amount of methane into the air.

Question 367

22.Dissolved oxygen in rivers is close to _________ parts per million. (A) 125 (B) 25 (C) 5 (D) 0

Answer 367

(C) (SSC CHSL 2016) Exp: DO in river is 3-5 ppm. (DO) Dissolved oxygen is used to check the pollution level. Greater the DO less will be the pollution.

Question 368

23.Sulphur dioxide pollution is indicated by an excessive growth of which of the following? (A) Algal Blooms (B) Lichens (C) Bryophytes (D) Protozoa

Answer 368

(B)Exp: Lichens show symbiotic relationship between algae and fungi. If air is very badly polluted with sulphur dioxide there may be no lichens present.

Question 369

24.What does BOD5 refer to? (A) Biochemical Oxygen Demand in 5 days (B) Biochemical Oxygen Demand in 5 hours (C) Biochemical Oxygen Demand in 5 minutes (D) Biochemical Oxygen Demand in 5 Months

Answer 369

(A) (SSC CHSL 2016) Exp: Determination of BOD of a sample of water requires 20-30 days for the complete decomposition of waste. Therefore usually we determine BOD5, i.e. the amount of oxygen consumed in 5 days. Pure water has 3-5 ppm BOD. The untreated municipal sewage has BOD5 of 100-400 ppm.

Question 370

25.Release of which among the following is the primary reason for depletion of the ozone layer? (A) Nitrous oxide (B) Hydrogen dioxide (C) Chlorofluoro carbon (D) Carbon monoxide

Answer 370

(C) (SSC CHSL 2016) Exp: Chlorofluoro carbon (CFC) i.e. compounds containing chlorine, fluorine and carbon commonly known as freon. Freons are responsible for Ozone depletion.

Question 371

26.Which gas contributes most to the Greenhouse effect? (A) Water vapour (B) Ozone (C) Oxygen (D) Nitrogen

Answer 371

(A) (SSC CHSL 2016) Exp: In the given options, only water vapour gas contributes more. But ozone contribution is negligible.

Question 372

27.Which atmospheric layer contains ozone layer? (A) Genosphere (B) Zonosphere (C) Stratosphere (D) Ionosphere

Answer 372

(C) (SSC CHSL 2016) Exp: In the stratosphere (11-50 km), the oxygen started partially being converted into ozone. Now at an altitude of 25 - 30 km, we have a layer in which the concentration of ozone is about 10ppm. It is called ozone layer.

Question 373

28.Which of the following gas was leaked in the Bhopal Gas tragedy in December 1984? (A) Methyl isocyanate (B) Methyl isochlorate (C) Methyl phosphate (D) Methyl isopropate

Answer 373

(A) (SSC CHSL 2016) Exp: Methyl isocyanate (CH3CNO) gas was leaked in the Bhopal gas tragedy in December 1984.

Question 374

29.What will be the form of Nitrogen in sewage water is completely oxidized? (A) Nitrite (B) Ammonia (C) Nitramine (D) Nitrate

Answer 374

(D) [SSC MTS 2013] Exp: If sewage water is completely oxidized then Nitrogen gets converted into nitrates.

Question 375

30.Catalytic Converters are generally made from- (A) Hydrogen (B) Carbon (C) Transition Metals (D) Alkaline Metals

Answer 375

(C) [SSC CGL 2015] Exp: Catalytic converters are generally made from transition metals which convert toxic gases to less toxic pollutants.

Question 376

31.The Gas causes acid rain in an industrial area is- (A) Sulphur dioxide (B) Methane (C) Carbon dioxide (D) Carbon monoxide

Answer 376

(A) [SSC CHSL 2013] Exp: The gas causes acid rain in industrial areas is sulphur dioxide (SO2). SO2 oxidation SO3 SO3 + H2O H2SO4

Question 377

32.Acid rain in the environment is caused by the higher concentration of - (A) CO and CO2 (B) SO2 and NO2 (C) Ozone and dust (D) H2O and CO

Answer 377

(B) [SSC FCI 2012] Exp: Acid rain in the environment is caused by the higher concentration of SO2 & NO2. Both gases react with water to form H2SO4 & HNO3. H2SO4 contributed 60-70% and HNO3 contributes 30-40%. When the pH of rain water falls below 5.6, it becomes acid rain.

Question 378

“33.Air pollution by ““Fly Ash”” is caused by- (A) Fertilizer plant (B) Coal Combustion in thermal power plant (C) Cement industry (D) Floor Mill”

Answer 378

(C) [SSC CPO 2012] Exp: Portland cement contains 35% of fly ash, which causes air Pollution.

Question 379

34.Acute Lead poisoning is also known as - (A) Itai-Itai (B) Plumbism (C) Neuralgia (D) Byssinosis

Answer 379

(B) [SSC CHSL 2010] Exp: Disease caused by lead poisoning is known as Plumbism. Abdominal pain, weight loss, delay in development are some symptoms.

Question 380

35.Maximum permissible concentration of copper in drinking water in mg/L is - (A) 0.01 (B) 0.05 (C) 1.0 (D) 2.0

Answer 380

(D) [SSC CHSL 2011] Exp: According to the notification published by WHO ‘Guidelines for drinking water quality’ in 2011 (4th edition), Maximum permissible concentration of Copper in drinking water is 2.0mg/L

Question 381

36.Brass gets discoloured in air due to the presence of which gas in air?(A) Nitrogen (B) Hydrogen sulphide (C) Oxygen (D) Carbon dioxide

Answer 381

(B) [SSC CGL 2013] Exp: Copper and Zinc combined to form Brass. Copper reacts with Hydrogen sulphide to form a black coloured compound copper sulphide and as a result of it brass gets discoloured

Question 382

37.Which one of the following is the Moto of Pollution controlling programme to reduce the disposal of waste in rivers? (A) Oxygen consumer (B) Oxygen producer (C) Carbon producer (D) Sulphur producer

Answer 382

(A) [SSC Steno Exam, 2015] Exp: The main Moto of pollution controlling programme is to reduce the disposal of oxygen consuming waste in rivers. The pollutant which decreases the amount of oxygen in water is known as Oxygen consumers.

Question 383

38.The main cause of air pollution in big cities is- (A) Waste water (B) Suspended particles (C) Combustion of Fossil Fuel (D) Thermal power Plant

Answer 383

(B) [SSC Steno Exam, 2012] Exp: Small solid particles and liquid droplets suspended in air are collectively called as Suspended particles (Particulates). Sources of particulates- (A) Natural sources- Volcanic eruption, grinding, blowing of dust and soil by the wind spraying of salts by seas and oceans etc. (B) Man made sources - soot, flyash

Question 384

39.The word ‘Brown air’ is used for- (A) Acidic Smoke (B) Industrial Smoke (C) Photochemical Smog(D) Sulphur Smoke

Answer 384

(C) [SSC CGL Exam, 2015] Exp: Brown air word is used for photochemical smog Photochemical smog is obtained by the reaction of air pollutant and sunlight. Its main constituent gases are Hydrocarbon, Nitrogen oxide, PAN (Peroxyl acetyl Nitrate).

Question 385

40.Tajmahal is affected by which of the following? (A) SO2 (B) CO (C) NO (D) CO2

Answer 385

(A) [SSC Steno 2014] Exp: Taj Mahal is affected by acid rain which mainly contains H2SO4 & HNO3. SO2 & NO2 react with rain water to form H2SO4 & HNO3 respectively.

Question 386

41.Automob i le exhausted in the harmfu l compound- (A) Carbon dioxide (B) Carbon monoxide (C) Smoke (D) All of these

Answer 386

(D) [SSC Steno Exam, 2014] Exp: Automobile exhausts harmful compounds such as carbon dioxide, carbon monoxide, smoke, Nitrogen oxide, sulphur dioxide etc.

Question 387

42.Amount of sulphur dioxide can be reduced by the use of- (A) More efficient car engine (B) By using catalytic convertor in industry. (C) By using static electricity in chimneys of factories to attract it. (D) Fuel containing low sulphur

Answer 387

(D) [SSC MTS 2013] Exp: Sulphur dioxide pollution can be controlled in a number of ways as follows- (i) By using Low sulphur or sulphur free fuels like natural gas. (ii) By removing sulphur from the fuel (eg:- from fuel oil) before burning. (iii)By making sulphur-free Liquified gaseous fuel from coal.

Question 388

43.Burning Pyrites ore gives out- (A) Carbon dioxide gas (B) Sulphur dioxide gas (C) Nitrogen dioxide gas (D) Nitric oxide gas

Answer 388

(B) [SSC Steno 2011, SSC CHSL 2010] Exp: Pyrites ores are sulphide of metals. Burning of pyrite ore gives out sulphur dixoide gas. The SO2 produced, is ultilised for the manufacturing of H2SO4. e.g. Iron pyrite (FeS2), Copper pyrites (CuFeS2). 44. Disadvantage of using DDT as pesticide is - (A) It becomes ineffective after some time (B) Not easily degradable in nature (C) Less effective than others (D) Its High cost (B) [SSC CHSL 2012] Exp: As a pesticide DDT does not decompose easily in nature while its concentration goes on increasing from one level to another in a food chain is known as Bio Magnification.

Question 389

44.Example of macro pollutants are - (A) CH4 (Methane) (B) Cl2 (Chlorine) (C) CFCs (Chlrorofluoro carbons) (D) PAN (Peroxyl acetyl Nitrate)

Answer 389

(D) [SSC Steno 2012] Exp: PAN (Peroxyl acetyl Nitrate) is a macro pollutant. It is a pollutant present in photochemical smog.

Question 390

45.What is Peroxyl? (A) Acidic acid (B) Macro pollutant (C) Vitamin (D) Plant hormone

Answer 390

(B) [SSC CGL Exam, 2015] Exp: PAN (Peroxyl acetyl Nitrate) is a macro pollutant. It is a powerful eye & respiratory irritant present in photo chemical smog.

Question 391

46.Photochemical smog is the resultant of reaction among- (A) Higher concentration of NO2, O3, CO in the evening(B) CO, CO2, NO2 at Low temperature (C) CO, O2 and peroxyl acetyl Nitrate is the presence of sunlight (D) NO2, O3 and Peroxyl Nitrate in the sunlight.

Answer 391

(D) [SSC CGL Exam, 2015] Exp: Photochemical smog is the result of reaction of (NO2) Nitrogen dioxide and vapourised compounds in the presence of sunlight. Following conditions are necessary for its formation. 1. Sunlight 2. Nitrogen dioxide 3. Temperature greater than 18ºC By the result of this reaction toxic constituent peroxylacetyl Nitrate is produced.

Question 392

47.The toxic gas present in the smoke exhausted by cars is- (A) CO (B) CO2 (C) C2H4 (D) CH4

Answer 392

(A) [SSC MTS 2014] Exp: Car and other automobiles exhaust mainly contains CO, lead and SO2 and out of these CO is the most toxic.

Question 393

48.Pollutant from Motor car exhaust that causes mental disease is - (A) Lead (B) NO2 (C) SO2 (D) Hg

Answer 393

(A) [SSC CHSL 2010] Exp: Lead is the pollutant exhausted from motor car that causes mental disease.

Question 394

49.In which year Chernobyl nuclear power plant of the former USSR had accident that caused escape of radio nuclides into atmosphere? (A) 1979 (B) 1980 (C) 1984 (D) 1986

Answer 394

(D) [SSC CGL 2012] Exp: Accident at Chernobyl nuclear power plant occurs on April 26 in 1986.

Question 395

“50.Taj Mahal is said to be suffering from ““Marble Cancer””. What is marble Cancer? (A) Smokes Filling the Taj Mahal from adjoining industries. (B) Acidic rain which corrodes Marble (C) Large no of fungus in Taj Mahal Marbles (D) Yellowing of marble on account of soot particles.”

Answer 395

(B) Exp: The marble cancer refers to the corrosion of building and statues made up of marbles by the action of sulphuric acid and Nitric acid. Acid rain is the cause of ‘Marble Cancer’ of Taj Mahal. Marble cancer causes disintegration and yellowing of the building or statue. Taj Mahal is loosing its white shine because of marble cancer.

Question 396

51.Which one of the following gas is not a part of atmosphere? (A) Nitrogen (B) Helium (C) Chlorine (D) None of these

Answer 396

(C) [SSC CPO Exam, 2008] Exp: Nitrogen is present in 78%, oxygen is 21% and carbon dioxide, water vapour and Noble gases are 1%. Chlorine is not the part of atmosphere.

Question 397

52.Freon is used as a - (A) Insecticide (B) Herbicide (C) Fungicide (D) Coolant

Answer 397

(D) [SSC MTS 2006] Exp: The chlorofluoro carbon compounds of methane and ethane are collectively known as freon. They are used as refrigerants and as aerosol propellants. Freons are responsible for Ozone depletion. Freon -12 (CCl2F2) is one of the most common freon in industrial use.

Question 398

53.Black Lung disease occurs in people working in - (A) Electroplating industry (B) Organic solvent industry (C) Paint Manufacturing industry (D) Coal mines

Answer 398

(D) [SSC CHSL 2011] Exp: Black lung disease is caused by long exposure to coal dust. It is common in coal miners and others who works with in coal industry.

Question 399

54.Micro organism which monitor the air pollution- (A) Bacteria (B) Lichen (C) Alage (D) Fungi

Answer 399

(B) [SSC CHSL Exam, 2013] Exp: Lichens are indicator of air pollution mainly SO2 gas. A lichen consists of an Alga and a fungus living together in a symbiotic relationship. The Alga by photsynthesis produce food while the fungus protect the Alga and provides water and minerals to it. The fungus forms the main body of lichens.

Question 400

55.Main Gaseous pollutant of thermal power plants is- (A) H2S (B) NH3 (C) NO2 (D) SO2

Answer 400

(D) [SSC Tax Asst. Exam,2009] Exp: Combustion of sulphur containing coal and oil fuel in the thermal power plant produce SO2 gas. SO2 at a concentration of 5ppm causes throat and eye irritation resulting into cough tears and redness in eyes. It causes breath-lessness and affects larynx. (Voice box).

Question 401

56.Acid rain destroy vegetation because it contains- (A) Nitric Acid (B) Ozone (C) Carbon Monoxide (D) Sulphuric acid

Answer 401

(D) [SSC Tax Asst. 2006] Exp: Acid rain contains about 60-70% H2SO4 & 30-40% HNO3.

Question 402

57.A hard fluid present in smog which causes irritation in eyes is- (A) Nitric Acid (B) Sulphur dioxide (C) Peroxylacetyl Nitrate(D) Carbon dioxide

Answer 402

(C)Exp: Nitrous oxide reacts with volatile organic compounds (except methane) to form a Peroxylacetyl nitrates or PAN a third component of smog. PAN makes smog more irritating to eyes.

Question 403

58.Acid rain is caused by- (A) NO2 and O2 (B) CO and CO2 (C) SO2 and O2 (D) SO2 and NO2

Answer 403

(D) [SSC CGL 2014] OR

Question 404

Acid rain is caused due to pollution of atmosphere by- (A) Oxides of carbon and Nitrogen (B) Oxides of Nitrogen and Phosphorous (C) Oxides of Nitrogen and Sulphur (D) None of these

Answer 404

(C) [SSC CPO 2015] Exp: Acid rain is caused by the gaseous pollutant SO2 and NO2 present in atmosphere. In air, Sulphur dioxide (SO2) react with water (H2O) to form sulphuric acid (H2SO4) and Nitrogen dioxide (NO2) react with water to form Nitric acid (HNO3). Acid rain has pH less than 5.6.

Question 405

59.Photochemical smog occurs in warm, dry and sunny climate. One of the following is not amongst the components of photochemical smog. Identify it (A) NO2 (B) O3 (C) SO2 (D) Unsaturated hydrocarbons

Answer 405

(C) Exp: It is a mixture of a number of irritation causing compounds like NO2, O3, PAN, aldehydes, ketones, hydrocarbons and CO. It is oxidizing in character.

Question 406

60.Which one of the following gas is most toxic? Or Which of the following gas is exhausted by automobiles cause air pollution and Mainly Harmful. [SSC Tax Asst. 2007] (A) Carbon dioxide (B) Carbon monoxide (C) Sulphur dioxide (D) Chlorine

Answer 406

(B) Exp: Carbon monoxide gas is most toxic from the given options. It is produced by incomplete combustion of fuel such as natural gas, coal or wood. Vehicular exhausts are the largest source of carbon monoxide. It accounts for over 50% of the total air pollution. Another source of air pollution is cigarette smoke. It reduces the oxygen carrying capacity of blood.

Question 407

Chief pollution of smoke of cigarette contains- (A) Carbon monoxide and Dioxin (B) Carbon monoxide and Nicotine (C) Carbon monoxide and Benzene (D) Dioxin and Benzene

Answer 407

(B) [SSC Tax Asst. 2008] Exp: Carbon monoxide is main air pollutant. Carbon monoxide reduces the oxygen carrying capacity of blood and nicotine is Carcinogenic. (Cancer producing substance).