Question

______ (Carbon dioxide/Carbon monoxide) gas dissolves in water to form carbonic acid.

Answer 1

• Acids when dissolved in water taste sour because of the formation of an acidic solution. In the same way, carbon dioxide when dissolved in water imparts a sour taste because of the formation of carbonic acid which in turn dissociates to produce proton (H⁺) and bicarbonate ion (HCO₃^-).

$\underset{\mathbf{Carbon}\mathbf{}\mathbf{dioxide}}{{\mathbf{CO}}_{\mathbf{2}}\mathbf{\left(}\mathbf{g}\mathbf{\right)}}\mathbf{}\mathbf{+}\underset{\mathbf{Water}}{\mathbf{}{\mathbf{H}}_{\mathbf{2}}\mathbf{O}\mathbf{\left(}\mathbf{l}\mathbf{\right)}}\mathbf{}\mathbf{}\mathbf{\rightleftharpoons }\underset{\mathbf{Carbonic}\mathbf{}\mathbf{acid}}{\mathbf{}{\mathbf{H}}_{\mathbf{2}}{\mathbf{CO}}_{\mathbf{3}}}\mathbf{}\mathbf{\rightleftharpoons }\mathbf{}\mathbf{}\underset{\mathbf{Proton}}{{\mathbf{H}}^{\mathbf{+}}\mathbf{\left(}\mathbf{aq}\mathbf{\right)}}\mathbf{}\mathbf{+}\mathbf{}\underset{\mathbf{Bicarbonate}\mathbf{}\mathbf{ion}}{{{\mathbf{HCO}}_{\mathbf{3}}}^{\mathbf{-}}\mathbf{\left(}\mathbf{aq}\mathbf{\right)}}$

• On the other hand, carbon monoxide (CO) is less soluble than carbon dioxide. It reacts with water at high temperatures, giving rise to the formation of carbon dioxide and hydrogen.

Thus,Carbon dioxide gas dissolves in water to form carbonic acid.