Question

Which of the following gas is formed when an acid reacts with a metal carbonate or metal hydrogen carbonate?

• A. Hydrogen
• B. Carbon dioxide
• C. Carbon monoxide
• D. All of the above

Answer 1

The correct option is B

Carbon dioxide

Explanation for correct option:

B. Carbon dioxide

Reaction of acid with metal carbonate:

• When acid reacts with metal carbonate or metal hydrogen carbonate, it produces salt, and carbon dioxide$\left({\mathrm{CO}}_2\right)$ is liberated along with water$\left({\mathrm{H}}_2\mathrm{O}\right)$.
• The chemical reaction is depicted as:

$\mathrm{Acid}+\mathrm{Metal}\mathrm{carbonate}/\mathrm{Metal}\mathrm{hydrogen}\mathrm{carbonate}\to \mathrm{Metal}\mathrm{salt}+\mathrm{Carbon}\mathrm{dioxide}+\mathrm{water}$

Example of the reaction with acid with metal carbonate:

• When Sodium carbonate$\left({\mathrm{Na}}_2{\mathrm{CO}}_3\right)$ reacts with hydrochloric acid$\left(\mathrm{HCl}\right)$, sodium chloride$\left(\mathrm{NaCl}\right)$ is formed with water$\left({\mathrm{H}}_2\mathrm{O}\right)$ along with the liberation of carbon dioxide$\left({\mathrm{CO}}_2\right)$.
• The chemical reaction can be depicted as:

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

Explanation for incorrect options:

When an acid reacts with a metal carbonate or metal hydrogen carbonate, carbon dioxide is formed. Thus options A, C, and D are incorrect.

Hence, the correct option is B i.e. carbon dioxide.