Solutions

Question 1

Alloy BRASS contains elements……/……

Answer 1

Copper
Zinc

Question 2

Statement I:German silver consists of elements Cu, Ni and Zn.
Statement II:Bronze consists of Cu and Au.

Answer 2

Statement I is correct and statement II is incorrect
Cu and Au form alloy TUMBAGA
BRONZE consists of Cu with Sn

Question 3

………….. part per million (ppm) of fluoride ions in water prevents tooth decay, while……….. ppm causes the tooth to become mottled.

Answer 3

1

1.5

Question 4

Sodium fluoride is used in………

Answer 4

rat poison

Question 5

The ………….. determines the physical state in which solution exists

Answer 5

Solvent

Question 6

Commercial bleaching solution contains 1.62 mass percentage of sodium hypochloride in water.
True or false?

Answer 6

False
commercial bleaching solution contains 3.62 mass percentage of sodium HYPOCHLORITE in water

Question 7

………..% (v/v) solution of ethylene glycol, an antifreeze, is used in cars for cooling the engine.

Answer 7

35

Question 8

At this concentration the antifreeze lowers the freezing point of water to……

Answer 8

255.4K

–17.6°C

Question 9

Another concentration unit which is commonly used in medicine and pharmacy is………

Answer 9

Mass by volume percentage

Question 10

A litre of sea water contains about 6 × 10–3 g of dissolved oxygen which can be represented as……..

Answer 10

5.8 ppm

Question 11

concentration of pollutants in water or atmosphere is often expressed in terms of………

Answer 11

microgm/L or ppm.

Question 12

Statement 1: naphthalene and anthracene dissolve readily in water
Statement 2: sodium chloride and sugar dissolve readily in benzene

Answer 12

Both are incorrect
naphthalene and anthracene dissolve readily in benzene
sodium chloride and sugar dissolve readily in water,

Question 13

Solute particles in solution collide with the solid solute particles and get separated out of solution. This process is called as………

Answer 13

Crystallisation

Question 14

Solution in which no more solute can be dissolved at the same……./……. is called a saturated solution.

Answer 14

temperature and pressure

Question 15

In case of solution of solid in liquid if dissolution is endothermic solubility……….. with temperature and for exothermic solubility………. With temperature

Answer 15

Increases
Decrease

Question 16

Assertion: Pressure does not have any significant effect on solubility of solids in liquids.

Answer 16

Reason: solids and liquids are highly incompressible and practically remain unaffected by changes in pressure.

Question 17

Assertion: The solubility of gases increase with increase of pressure

Answer 17

Reason: This will increase the number of gaseous particles per unit volume over the solution and also the rate at which the gaseous particles are striking the surface of solution to enter it.

Question 18

Henry’s law.

Answer 18

The law states that at a constant temperature, the solubility of a gas in a liquid is directly proportional to the partial pressure of the gas present above the surface of liquid or solution.

Question 19

Assertion: Aquatic species are more comfortable in cold waters rather than in warm waters.

Answer 19

Reason: KH value for O2 increase with increase of temperature indicating that the solubility of gases increases with decrease of temperature

Question 20

Applications of Henry’s law

Answer 20

1 increase the solubility of CO2 in soft drinks and soda water, the bottle is sealed under high pressure.
2 Prevent bends in scuba divers
3 Prevent anoxia at high altitudes

Question 21

Tanks used by scuba divers are filled with air diluted with helium having gaseous composition as……….

Answer 21

11.7% helium
56.2% nitrogen
32.1% oxygen

Question 22

For solution of gases in liquids dissolution is an………..process thus solubility shows……….with increase of temperature.

Answer 22

exothermic
decrease

Question 23

H2S,a toxic gas has……….. like smell

Answer 23

rotten egg like smell

Question 24

French chemist, Francois Marte Raoult 1886 gave the quantitative relationship known as …….

Answer 24

Raoult’s law

Question 25

At equilibrium, vapour phase will be always rich in the component which is more……..

Answer 25

volatile

Question 26

Raoult’s law becomes a special case of Henry’s law

Answer 26

Only the proportionality constant Kh differs from p0.

Question 27

Assertion:Decrease in the vapour pressure of water by adding 1.0 mol of sucrose to one kg of water is nearly similar to that produced by adding 1.0 mol of urea to the same quantity of water at the same temperature.

Answer 27

Reason: decrease in the vapour pressure of solvent depends on the quantity of non-volatile solute present in the solution, irrespective of its nature.

Question 28

Assertion: ethanol and acetone show positive deviation.

Answer 28

Reason: Due to weakening of interactions[ hydrogen bonds in ethanol] because of interference of acetone molecules, the solution shows positive deviation from Raoult’s law

Question 29

Assertion: Phenol and aniline show negative deviation.

Answer 29

Reason: Intermolecular hydrogen bonding between phenolic proton and lone pair on nitrogen atom of aniline is stronger than the respective intramolecular hydrogen bonding

Question 30

Assertion: Chloroform and acetone forms a solution with negative deviation

Answer 30

Reason: Chloroform molecule is able to form hydrogen bond with acetone molecule

Question 31

ethanol-water mixture (obtained by fermentation of sugars) on fractional distillation gives a solution containing approximately……….% by volume of ethanol. It forms azeotroe.

Answer 31

95

Question 32

68% nitric acid and 32% water by mass, with a boiling point of 393.5 K. Forms …………. boiling azeotrope.

Answer 32

Maximum

Question 33

The osmotic pressure of a solution is the excess pressure that must be applied to the …….. side to prevent osmosis, i.e., to stop the passage of………… molecules through a semipermeable membrane into the solution.

Answer 33

Solution solvent

Question 34

Statement 1:Measurement of osmotic pressure provides another method for determining molar masses of solutes. Statement 2: This method is widely used to determine molar masses of proteins, polymers and other micro molecules.

Answer 34

Statement 1 is correct but statement 2 is incorrect This method is widely used to determine molar masses of proteins, polymers and other macromolecules.

Question 35

Assertion: Osmotic pressure method has an advantage over other methods.

Answer 35

Reason: Pressure measurement is around the room temperature and molarity of solution is used instead of molality. Particularly useful for Biomolecules which are unstable at high temperatures and polymers which have low solubility

Question 36

Osmotic pressure associated with the fluid inside the blood cell is equivalent to that of…….% (mass/volume) sodium chloride solution, called ……………….

Answer 36

0.9 normal saline solution

Question 37

In 1880 van’t Hoff introduced a factor i, known as the van’t Hoff factor, to account for the extent of……../………

Answer 37

dissociation or association.

Question 38

Ascending order of HENRY’s law constants table:

Answer 38

1. Formaldehyde: 1.83 \times 10^{-5} kbar 2. Methane: 0.413 kbar 3. Vinyl chloride: 0.611 kbar 4. CO₂: 1.67 kbar 5. O₂ (298 K): 34.86 kbar 6. O₂ (303 K): 46.82 kbar 7. Argon: 40.3 kbar 8. N₂ (293 K): 76.48 kbar 9. N₂ (303 K): 88.84 kbar 10. H₂: 69.16 kbar 11. He: 144.97 kbar

Question 39

Kb values in increasing order table:

Answer 39

• Carbon disulphide (319.4 K) • Diethyl ether (307.8 K) • Chloroform (334.4 K) • Carbon tetrachloride (350.0 K) • Ethanol (351.5 K) • Benzene (353.3 K) • Cyclohexane (353.74 K) • Water (373.15 K) • Acetic acid (391.1 K)

Question 40

Boiling point elevation constant[Kb values] order lowest to highest

Answer 40

From lowest to highest: • Water (0.52 K kg mol⁻¹) • Ethanol (1.20 K kg mol⁻¹) • Carbon disulphide (2.34 K kg mol⁻¹) • Diethyl ether (2.02 K kg mol⁻¹) • Acetic acid (2.93 K kg mol⁻¹) • Cyclohexane (2.79 K kg mol⁻¹) • Benzene (2.53 K kg mol⁻¹) • Chloroform (3.63 K kg mol⁻¹) • Carbon tetrachloride (5.03 K kg mol⁻¹)

Question 41

Freezing Point Depression Constant ( K_f ): From lowest to highest:

Answer 41

• Water (1.86 K kg mol⁻¹) • Ethanol (1.99 K kg mol⁻¹) • Diethyl ether (1.79 K kg mol⁻¹) • Benzene (5.12 K kg mol⁻¹) • Acetic acid (3.90 K kg mol⁻¹) • Carbon disulphide (3.83 K kg mol⁻¹) • Chloroform (4.79 K kg mol⁻¹) • Cyclohexane (20.00 K kg mol⁻¹) • Carbon tetrachloride (31.8 K kg mol⁻ ¹)

Question 42

When solute get precipitated solution is known as

Answer 42

supersaturated solution.

Question 43

Though the concentration of solution doesn’t affect the vant Hoff factor much but as per the NCERT table 1.4 the value of vant hoff factor ……………. With dilution.

Answer 43

Increases

Question 44

Chloroform is soluble in water True or false

Answer 44

False It is insoluble

Question 45

For solution with concentration less than………. It is considered dilute

Answer 45

10%

Question 46

Pressure of pure water if not given then considered as………..

Answer 46

760mmHg

Question 47

Positive deviation from roults law

Answer 47

Cyclobexasol and eyclobexane Ethyl alcohol & Acetone Carbon Disulphide & Acetone Methyl alcohol and water

Question 48

Negative deviation from raults law

Answer 48

CHCl3& benzene Phenol & Aniline CHCl3 & Acetone CACl3 & Et-O-Et Water & Acid

Question 49

Ziegler -Natta catalyst is a mixture of titanium tetrachloride and an alkyl derivative of aluminium i.e.

Answer 49

Al2(C2H5)6. TiCl3

Question 50

Statement 1: The addition of ethylene glycol to water raises the boiling point of the solution Statement 2: It helps in prevention of boil overs

Answer 50

Both are correct

Question 51

Berkeley Huntley method and funnel experiment is used for

Answer 51

Determining osmotic pressure

Question 52

Name one compound that doesn’t obey Henry’s law

Answer 52

Ammonia NH3

Question 53

Ascorbic acid

Answer 53

Vitamin C C6H8O6

Question 54

Nalorphene

Answer 54

C9H21NO3 Similar to morphine Used to combat withdrawal symptoms in narcotic users Dose given is generally 1.5mg

Question 55

…….. sprayed on snow makes it melt

Answer 55

CaCl2