Testing for Different Gases

Question 1

How do we test for the presence of oxygen?

Answer 1

1. Oxygen supports combustion

2. A glowing splint will relight if oxygen is present

Question 2

How do we test for the presence of hydrogen?

Answer 2

1. Hydrogen ignites in air

2. If hydrogen is present, a lighted splint will make a squeaky pop when placed near the mouth of a test tube

Question 3

How do we test for the presence of carbon dioxide?

Answer 3

1. Carbon dioxide reacts with calcium hydroxide solution to produce a white precipitate of calcium carbonate.
2. Limewater is a solution of calcium hydroxide,
3. If CO2 is present, the limewater will turn milky

Question 4

How do we test for the presence of chlorine?`

Answer 4

1. Chlorine gas is acidic and acts as bleach
2. Will turn damp litmus paper white
3. Will turn damp BLUE litmus paper red then white