Question

Name two compounds that are covalent when taken pure but produce ions when dissolved in water.

Answer 1

Covalent compounds are molecular compounds i.e.; they do not have ions. But on dissolution in water, they furnish ions as shown below:

(1) Hydrogen chloride

$$\begin{gathered} \mathrm{HCl}+{\mathrm{H}}_2\mathrm{O}\rightleftharpoons {\mathrm{H}}_3{\mathrm{O}}^{+}+{\mathrm{Cl}}^{-} \\ (\mathrm{Hydrogen}\mathrm{chloride})\left(\mathrm{Water}\right)(\mathrm{Hydronium}\mathrm{ions})(\mathrm{Chloride}\mathrm{ions}) \end{gathered}$$

(2) Ammonia

$$\begin{gathered} {\mathrm{NH}}_3+{\mathrm{H}}_2\mathrm{O}\rightleftharpoons {\mathrm{NH}}_4^{+}+{\mathrm{OH}}^{-} \\ \left(\mathrm{Ammonia}\right)\left(\mathrm{Water}\right)(\mathrm{Ammonium}\mathrm{ions})(\mathrm{Hydroxide}\mathrm{ions}) \end{gathered}$$