Question

A substance X which is used as an antacid reacts with dilute hydrochloric acid to produce a gas Y which is used in one type of fire-extinguisher. Name the substance X and gas Y. Write a balanced equation for the chemical reaction which takes place.

Answer 1

Substance X is Sodium hydrogen carbonate (Baking soda).

Gas Y is Carbon dioxide (CO₂).

\[\ce{HCl_{(aq)} + NaHCO3_{(aq)} -> NaCl_{(aq)} + H2O_{(l)} + CO2_{(g)}}\]

Sodium hydrogen carbonate is a mild base that neutralises excess hydrochloric acid in the stomach. Their reaction produces carbon dioxide gas, which does not support combustion and is used to extinguish fires.