Question

Sodium salt $\left(A\right)$ of a dibasic acid $\underset{}{\overset{HCl}{\to }}gas\left(B\right)$ and clear solution

Gas $\left(B\right)$ turns lime water milky. Identify $\left(A\right)$.

• A. Sodium carbonate
• B. Sodium sulphate
• C. Sodium oxalate
• D. Sodium nitride

Answer 1

The correct option is A Sodium carbonate

Option (A) is correct. Compound $A$ is sodium carbonate. It reacts with $HCl$ to liberate carbon dioxide gas.

$N{a}_{2}C{O}_3\left(A\right)$ $\underset{}{\overset{HCl}{\to }}$ $N{a}_{2}O+C{O}_2\left(B\right)$

$C{O}_2$ gas turns lime water milky due to formation of calcium carbonate.
$Ca(OH{)}_2+C{O}_2\to CaC{O}_3\downarrow +H_{2}O$