Test For Gases

Question 1

Test for H2 (Hydrogen)

Answer 1

Makes a pop sound in the presence of a lit splint

Colourless and odourless

No effect on moist indicator paper

Question 2

Test for O2 (Oxygen)

Answer 2

Relights a glowing splint

Colourless and odourless

No effect on moist indicator paper

Question 3

Test for CO2 (Carbon dioxide)

Answer 3

Turns Limewater cloudy white

Colourless and odourless

Turns damp blue litmus paper pink (weakly acidic)

Question 4

Test for NH3 (Ammonia)

Answer 4

Turns damp red litmus paper blue (only alkali gas)

Colourless but a very pungent smell

Question 5

Test for SO2 (Sulphur Dioxide)

Answer 5

Turns acidified potassium (VI) dichromate from orange to green
OR
Turns acidified acidified potassium (VII) manganate from purple to colourless

Colourless but very choking smell

Question 6

Test for Cl2 (Chlorine gas)

Answer 6

Bleaches damp litmus paper

Yellow-green and a very choking smell

Bleaches moist indicator paper after first turning pale pink

Question 7

Test for NO2 (Nitrogen(IV) Oxide)

Answer 7

Brown Colour + Turns moist indicator paper pink

Brown and a very choking smell

Turns damp, blue litmus paper pink (weakly acidic)

Question 8

Test for Water (H2O)

Answer 8

Turns blue cobalt chloride paper pink
OR
Turns anhydrous copper(II) sulfate from white to blue