The calcium hydroxide experiment demonstrates that
A)there is a much lower concentration of O₂ in expired air than in atmospheric air.
B)there is a much higher concentration of CO₂ in expired air than in atmospheric air.
C)there is a much higher concentration of O₂ in expired air than in atmospheric air.
D)there is a much lower concentration of CO₂ in expired air than in atmospheric air.
E)the concentrations of CO₂ in expired air and atmospheric air are approximately equal.

Question

Quizplus · Accepted Answer

Calcium hydroxide is used as a chemical indicator to determine the presence of carbon dioxide (CO₂) in expired air as it reacts with CO₂ to form calcium carbonate. Thus, if the calcium hydroxide turns milky, it indicates a high concentration of CO₂ in expired air compared to atmospheric air. Therefore, the correct choice is B.

The Calcium Hydroxide Experiment Demonstrates That