Question

Shamli took a piece of burning charcoal and collected the gas evolved in a test tube. The gas settled at the bottom of the test tube. Which of the following observations is correct?

• A. Gas evolved is acidic & heavier than air.
• B. Gas evolved is basic & heavier than air.
• C. Gas evolved is basic & lighter than air.
• D. Gas evolved is acidic & lighter than air.

Answer 1

The correct option is A

Gas evolved is acidic & heavier than air.

Burning charcoal in the presence of air produces carbon dioxide gas. $C{O}_2$ is denser than air and settles at the bottom of the test tube.
Carbon is a nonmetal, its oxide is acidic in nature. If a moist blue litmus paper is introduced, it will turn red confirming that $C{O}_2$ is acidic. The acid formed from $C{O}_2$ is carbonic acid ($H_{2}C{O}_3$).