Question

When we bubbled our exhaled air into the test tube containing limewater, and it went from clear to cloudy, this reaction occurred because exhaled air contains:
Group of answer choices

carbon dioxide


oxygen


heat


water vapor

Answer 1

The reaction that occurred when exhaling air into limewater, causing it to go from clear to cloudy, is due to the presence of **carbon dioxide** in exhaled air. When carbon dioxide is bubbled through limewater (calcium hydroxide solution), it reacts to form calcium carbonate, which is insoluble and causes the solution to become cloudy.

So the correct answer is **carbon dioxide**.