Multiple choice

Why the appearance of lime water in a test tube changes when we blow into it for a few times?

  1. The test tube may contain impurities which changes the appearance

  2. Lime water contains carbon dioxide which changes its appearance upon blowing

  3. Carbon dioxide in our exhaled air changes the appearance of lime water

  4. Oxygen in our exhaled air changes the appearance of lime water

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

fact