Question

_____ gas is evolved when dilute hydrochloric acid reacts with carbonates of metal.

• A. $H_{2}S$
• B. ${Cl}_2$
• C. $H_2$
• D. ${CO}_2$

Answer 1

The correct option is D

${\mathrm{CO}}_2$

Explanation:

• Metal carbonate undergoes reaction with dilute hydrochloric acid or hydrogen chloride $\left(\mathrm{HCl}\right)$ to form metal chloride, water $\left({\mathrm{H}}_2\mathrm{O}\right)$, and carbon dioxide $\left({\mathrm{CO}}_2\right)$.
• Sodium carbonate $\left({\mathrm{Na}}_2{\mathrm{CO}}_3\right)$ reacts with dilute hydrochloric acid or hydrogen chloride $\left(\mathrm{HCl}\right)$ to form sodium chloride $\left(\mathrm{NaCl}\right)$ , water $\left({\mathrm{H}}_2\mathrm{O}\right)$ and carbon dioxide $\left({\mathrm{CO}}_2\right)$ gas. The balanced chemical equation is as follows:

${\mathrm{Na}}_2{\mathrm{CO}}_3\left(\mathrm{aq}\right)+2\mathrm{HCl}\left(\mathrm{aq}\right)\to 2\mathrm{NaCl}\left(\mathrm{aq}\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)+{\mathrm{CO}}_2\left(\mathrm{g}\right)$

• Therefore, the gas evolved in the reaction is carbon dioxide gas $\left({\mathrm{CO}}_2\right)$, a colorless gas.

Final Answer:

Hence, the correct option is D.