Question

Acetic acid was added to a solid X and kept in a test tube. A colorless and odorless gas Y has evolved. The gas was passed through lime water which turned milky. Name X and Y and write the chemical reaction.

Answer 1

• The solid X is Sodium bicarbonate (NaHCO₃).
• The colorless and odorless gas Y evolved is Carbon dioxide (CO₂).
• When we add acetic acid (CH₃COOH) to sodium bicarbonate, carbon dioxide gas is liberated. When this gas is passed through lime water, it turns milky due to the formation of a white precipitate- calcium carbonate (CaCO₃).

The chemical reaction is:

${\mathrm{CH}}_3\mathrm{COOH}+{\mathrm{NaHCO}}_3\to {\mathrm{CH}}_3\mathrm{COONa}+{\mathrm{CO}}_2+{\mathrm{H}}_2\mathrm{O}$

Acetic Acid + Sodium bicarbonate → Sodium Acetate + Carbon dioxide + Water