Gas Tests

Question 1

Hydrogen test

Answer 1

Hydrogen ignites in air. If hydrogen is present in a test tube, a lighted splint held near its mouth ignites with a squeaky pop.

Question 2

Oxygen Test

Answer 2

Oxygen supports combustion. If oxygen is present in a test tube, a glowing splint relights when it is held inside.

Question 3

Carbon dioxide Test

Answer 3

Carbon dioxide reacts with calcium hydroxide solution to produce a white precipitate of calcium carbonate. Limewater is a solution of calcium hydroxide. If carbon dioxide is bubbled through limewater, the limewater turns milky or cloudy white.

Question 4

Chlorine Test

Answer 4

Chlorine is an acidic gas that also acts as a bleach. Damp litmus paper is bleached white when it is placed in chlorine.

Question 5

Summary of Gas Tests

Answer 5

Test Observation Inference
Glowing splint held in a test tube Splint relights Oxygen
Lighted splint held in a test tube Pop sound heard Hydrogen
Gas bubbled through limewater Limewater turns milky
or cloudy white Carbon dioxide
Damp litmus paper held
in a test tube Paper turns white Chlorine is present