Question

In the reaction between $\mathrm{HCl}$ and ${\mathrm{Na}}_2{\mathrm{CO}}_3$, what gas is formed?

Answer 1

Formation of ${\mathrm{Na}}_2{\mathrm{CO}}_3$:-

1. Sodium carbonate $\left({\mathrm{Na}}_2{\mathrm{CO}}_3\right)$ is actually a basic salt.
2. It is a salt of weak acid Carbonic acid $\left({\mathrm{H}}_2{\mathrm{CO}}_3\right)$ and a strong base Sodium hydroxide $\left(\mathrm{NaOH}\right)$.
3. The complete reaction is:-

$\underset{\mathrm{Sodium}\mathrm{hydroxide}}{2\mathrm{NaOH}\left(\mathrm{aq}\right)}+\underset{\mathrm{Carbonic}\mathrm{acid}}{{\mathrm{H}}_2{\mathrm{CO}}_3\left(\mathrm{aq}\right)}\to \underset{\mathrm{Sodium}\mathrm{carbonate}}{{\mathrm{Na}}_2{\mathrm{CO}}_3\left(\mathrm{aq}\right)}+\underset{\mathrm{Water}}{2{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)}$.

Reaction between $\mathrm{HCl}\mathrm{and}{\mathrm{Na}}_2{\mathrm{CO}}_3$:-

1. Hydrochloric acid is the strong acid whereas Sodium carbonate is the basic salt.
2. Both the Hydrochloric acid and Sodium carbonate will dissociate completely in solution.
3. The Hydrogen ions $\left({\mathrm{H}}^{+}\right)$ will bond with an Oxygen of the Carbonate leaving water, carbon dioxide, and dissolved $\mathrm{NaCl}$.
4. The chemical equation would be:-

$\underset{\mathrm{Sodium}\mathrm{carbonate}}{{\mathrm{Na}}_2{\mathrm{CO}}_3\left(\mathrm{aq}\right)}+\underset{\mathrm{Hydrochloric}\mathrm{acid}}{2\mathrm{HCl}\left(\mathrm{aq}\right)}\to \underset{\mathrm{Sodium}\mathrm{chloride}}{2\mathrm{NaCl}\left(\mathrm{aq}\right)}+\underset{\mathrm{Water}}{{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)}+\underset{\mathrm{Carbon}\mathrm{dioxide}}{{\mathrm{CO}}_2\left(\mathrm{g}\right)\uparrow }$

Therefore, In the reaction between $\mathrm{HCl}$ and ${\mathrm{Na}}_2{\mathrm{CO}}_3$, Carbon dioxide $\left({\mathrm{CO}}_2\right)$ gas is formed.