Chemical Reactions and Equations

Question 1

Calcium oxide and water

Answer 1

CaO + H2O&raquo_space; Ca(OH)2

Question 2

Calcium Carbonate is heated

Answer 2

CaCO3&raquo_space; CO2 + CaO

Question 3

Calcium Hydroxide and Carbon Dioxide

Answer 3

Ca(OH)2 + CO2&raquo_space; CaCO3 + H2O

Question 4

Methyl Alcohol

Answer 4

CH3OH

Question 5

Potassium Chlorate

Answer 5

KClO

Question 6

Magnesium + Oxygen

Answer 6

2Mg + O2&raquo_space; 2MgO

Question 7

Sulphuric Acid

Answer 7

H2SO4

Question 8

Zinc + Sulphuric Acid

Answer 8

Zn + H2SO4&raquo_space; ZnSO4 + H2

zinc sulphate

Question 9

Iron(4) + Water

Answer 9

3 Fe + 4 H2O&raquo_space; Fe3O4 + 4 H2

Question 10

CaO + H2O

Answer 10

Ca(OH)2 + Heat

Question 11

Quick lime

Answer 11

CaO (s)

Question 12

Slaked Lime

Answer 12

Ca(OH)2 (aq)

Question 13

Observations when we add water to quick lime

Answer 13

Rise in the temperature, formation of bubbles

Formation of white ppt [Ca(OH)2 or slaked lime]

Question 14

Burning of coal

Answer 14

C + O2&raquo_space; CO2

Question 15

Formation of water

Answer 15

O2 + 2H2&raquo_space; 2H2O

Question 16

Burning of gas (Methane)

Answer 16

CH4 + 2O2&raquo_space; CO2 + 2H2O

Question 17

Is respiration exothermic

Answer 17

Yes, it releases energy from food molecules

Question 18

3 examples of exothermic reactions

Answer 18

1. Burning of natural gas
2. Respiration
3. Decomposition

Question 19

Ferrous Sulphate is heated

Answer 19

2FeSO4&raquo_space; Fe2O3 + SO2 + SO3

Ferric oxide
Sulphur Dioxide/Trioxide

Question 20

Ferrous Sulphate Crystals are heated

eqn + obs

Answer 20

FeSO4.7H2O&raquo_space; FeSO4

light green to white

Anhydrous Ferrous Sulphate

Question 21

Ferrous Sulphate is heated observations

Answer 21

reddish brown solid is left out (Fe2O3)

smell of a gas having the odour of burning sulphur

Question 22

Lime Stone

Answer 22

CaCO3

Question 23

Calcium carbonate is heated

Answer 23

CaCO3&raquo_space; CO2 + CaO

Question 24

Quick Lime uses

Answer 24

CaO

white washing

manufacturing of cement, paper
preparing bleaching powder

Question 25

calcium hydroxide uses

Answer 25

sewage treatment, paper production, food processing.

Question 26

Lead nitrate is heated

Answer 26

2Pb(NO3)2 >> O2 + 4NO2 + 2PbO nitrogen dioxide lead oxide

Question 27

Silver Chloride in sun

Answer 27

2AgCl >> Cl2 + 2Ag

Question 28

Silver Bromide in sun

Answer 28

2AgBr >> Br2 + 2Ag

Question 29

Silver bromide and chloride are used for

Answer 29

bnw photography

Question 30

Barium Hydroxide and Ammonium chloride

Answer 30

Ba(OH)2 + 2NH4Cl >> BaCl2 + 2NH3 + 2H2O endothermic

Question 31

Electrolysis

Answer 31

Process of decomposing ionic compounds into their elements by passing a direct electric current through the compound in a fluid form

Question 32

In electrolysis of water, which gas is formed where

Answer 32

oxygen at the anode hydrogen at the cathode

Question 33

Iron and copper sulphate

Answer 33

Fe + CuSO4 >> FeSO4 + Cu

Question 34

Iron and Copper sulphate: observations

Answer 34

Iron nail has red coating (Cu deposit) Blue CuSO4 becomes green (FeSO4)

Question 35

Zinc + copper sulphate

Answer 35

Zn + CuSO4 >> ZnSO4 + Cu

Question 36

Lead and copper chloride

Answer 36

Pb + CuCl2 >> PbCl2 + Cu

Question 37

sodium sulphate and barium chloride

Answer 37

Na2SO4 + BaCl2 >> 2NaCl + BaSO4

Question 38

sodium sulphate and barium chloride obs

Answer 38

white ppt is formed (BaSO4)

Question 39

Copper and oxygen eqn obs

Answer 39

Black substance on copper powder Copper Oxide (CuO) 2Cu + O2 >> 2CuO

Question 40

Copper oxide and hydrogen eqn obs

Answer 40

CuO + H2 >> Cu + H2O black turns brown (Cu)

Question 41

Redox

Answer 41

A reaction where one reactant gets oxidised, the other gets reduced simultaneously

Question 42

Zinc oxide and carbon

Answer 42

ZnO + C >> CO + Zn

Question 43

Manganese dioxide and Hydrochloric acid

Answer 43

MnO2 + 4HCl >> MnCl2 + Cl2 + 2H2O

Question 44

Potassium iodide + Lead nitrate

Answer 44

2KI + Pb(NO3)2 >> PbI2 + 2KNO3

Question 45

Potassium iodide + Lead nitrate obs

Answer 45

yellow ppt is formed (lead iodide)

Question 46

example of endothermic reaction

Answer 46

Ba(OH)2 + 2NH4Cl >> BaCl2 + 2NH3 + 2H2O