Question

Short answer questions
How will you test the presence of carbon dioxide in exhaled air?

Answer 1

1. The aim is to show that carbon dioxide is present in exhaled air.
2. The following materials are required:

• Limewater (a saturated calcium hydroxide solution)
• A disposable transparent glass with a hole in the top
• plastic straw

Procedure:
1. Add limewater into the glass and cover it with a lid.
2. Put a straw into the lid's hole. Make sure it's been dipped in limewater.
3. Using the straw, blow air into the lime water in the glass.

Observation:
The limewater in the glass turns milky.

Conclusion:
The exhaled air being blown into the lime water contains carbon dioxide. As a result, carbon dioxide is present in exhaled air.