Confirmatory test for hydrogen gas?

The confirmatory test for hydrogen gas is the "pop test." In this test, a small amount of hydrogen gas is collected in a test tube and a lit match or flame is brought near the opening of the test tube. If the gas is hydrogen, it will ignite with a "pop" sound. This test is used to confirm the presence of hydrogen gas.

Pop Test

Materials:

- Hydrogen gas sample
- Pop bottle with a small opening
- Matches or lighter

Procedure:

1. Collect a small sample of hydrogen gas in the pop bottle.
2. Fill a small area in the pop bottle (about 10-15%) with the collected gas sample.
3. Place a finger over the opening of the bottle and shake it vigorously for a few seconds to mix the gases.
4. Remove your finger and quickly light a match or lighter near the opening of the bottle.

Observations:

- If hydrogen gas is present, a sharp "pop" sound will be heard.
- The flame will produce a pale blue color.

Explanation:

When hydrogen gas is mixed with air and ignited, it reacts rapidly with oxygen. This reaction releases a significant amount of energy, creating a small explosion and a distinctive "pop" sound. The pale blue color of the flame indicates the presence of hydrogen and water vapor.