Question

Name the cation furnished by an acid in aqueous solution.

Answer 1

1. Acids

Acids are those substances that have a tendency to give Hydrogen ions $\left({\mathrm{H}}^{+}\right)$ when dissolved in an aqueous solution. In an aqueous solution, the Hydrogen ions combine with water and form Hydronium ion $\left({\mathrm{H}}_3{\mathrm{O}}^{+}\right)$. It is represented as:

${\mathrm{H}}^{+}+{\mathrm{H}}_2\mathrm{O}\to {\mathrm{H}}_3{\mathrm{O}}^{+}$

2. Example

Hydrochloric acid (HCl) when dissolved in water liberates the Hydronium ion $\left({\mathrm{H}}_3{\mathrm{O}}^{+}\right)$ and Chloride ion $\left({\mathrm{Cl}}^{-}\right)$.

$\mathrm{HCl}\left(\mathrm{aq}\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)\to {\mathrm{H}}_3{\mathrm{O}}^{+}\left(\mathrm{aq}\right)+{\mathrm{Cl}}^{-}\left(\mathrm{aq}\right)$

Hence, the cation that is furnished by acid in an aqueous solution is hydronium ion $\left({\mathrm{H}}_3{\mathrm{O}}^{+}\right)$.