Preparing and Testing Oxygen

Oxygen can be produced by decomposing hydrogen peroxide. The reaction is sped up by a manganese(IV) oxide catalyst. The gas can be tested with a glowing splint, which relights in oxygen.

1. Place a small amount of solid manganese(IV) oxide (black powder) into a conical flask.
2. Pour hydrogen peroxide solution into the flask.
3. Collect the oxygen released using either a gas jar over water or a gas syringe.
4. Test the gas by placing a glowing splint into the collected sample. The splint will relight in oxygen.

Laboratory Preparation of Oxygen - The DIY Chemist:

To Prepare Oxygen and Examine its Properties - Simple Science and Maths:

📄 Oxygen - BBC Bitesize: https://www.bbc.co.uk/bitesize/guides/z7qw382/revision/5

• Use a gas syringe instead of a water bath and gas jar for cleaner collection.
• Try different catalysts (e.g., potassium iodide) and compare reaction speeds.
• Collect oxygen in balloons for demonstrations of combustion with other substances.

• Wear safety goggles and gloves.
• Hydrogen peroxide is an irritant — avoid contact with skin and eyes.
• Handle manganese(IV) oxide carefully; avoid inhaling dust.
• Ensure the splint is only glowing, not burning, to prevent accidents.

• What happens to a glowing splint in oxygen, and why? (It relights because oxygen supports combustion.)
• Why is manganese(IV) oxide added to hydrogen peroxide? (It acts as a catalyst to speed up decomposition.)
• What is the balanced chemical equation for this reaction? (2H2O2 → 2H2O + O2)
• Why is oxygen useful in medicine and welding? (It supports breathing for patients and increases flame temperature for cutting/welding metals.)