Experimental techniques & chemical analysis

Question 1

Soluble gases in water

Answer 1

• NH3
• Cl
• HCl
• SO2

Question 2

Slightly soluble gases in water

Answer 2

• O2
• CO2

Question 3

Insoluble gases in water

Answer 3

• H2
• CH4
• C2H6

Question 4

Denser gases than air

Answer 4

• Cl
• HCl
• SO2
• CO2

Question 5

Slightly denser gases than air

Answer 5

• O2
• C2H6

Question 6

Less dense gases than air

Answer 6

• NH3
• H2
• CH4

Question 7

Methods of collecting gases

Answer 7

• Displacement of water
• Upward delivery
• Downward delivery
• Gas syringe

Question 8

Displacement of water

Answer 8

insoluble / slightly soluble in water

Question 9

Upward delivery

Answer 9

less dense than air

Question 10

Downward delivery

Answer 10

denser than air

Question 11

Gas syringe

Answer 11

any gas irrespective of its solubility in water or density in air

Question 12

Collecting dry sample of gas

Answer 12

• drying agent -> H2SO4 , anhydrous CaO , anhydrous CaCl

Question 13

Separation of mixtures

Answer 13

• filtration
• decantation
• sublimation
• crystallisation
• simple distillation
• fractional distillation
• chromatography
• use of magnet
• use of separating funnel

Question 14

Solids that can sublime

Answer 14

• Ammonium chloride
• Iodine
• Solid carbon dioxide ( drikold )

Question 15

Fractional distillation

Answer 15

mixture of two / more miscible liquids with different BP can be separated

• only possible if they do not react with each other & have different BP

Question 16

Applications of fractional distillation

Answer 16

• alcohol distilleries
• oil refineries
• separation of nitrogen & oxygen from liquid air

Question 17

Uses of petroleum products

Answer 17

1) Natural gas -> fuel for cooking gas & light vehicles
2) Petrol -> fuel for light vehicles like cars
3) Naphtha -> feedstock in chemical properties
4) Kerosene -> fuel for aeroplanes
5) Diesel oil -> fuel for heavy vehicles
6) Motor oil -> lubricating oil
7) Bitumen -> road construction