Question

Explain why sodium chloride crystal does not conduct electricity but the molten or liquid state of sodium chloride conducts electricity.

Answer 1

Sodium chloride $\left(\mathrm{NaCl}\right)$ conducts electricity in its molten or liquid state due to the presence of freely moveable ions in the solution but in solid-state, the ions of sodium chloride are fixed i.e., not mobile ions (Na⁺ and Cl^-) to conduct electricity. So, sodium chloride crystals do not conduct electricity.

$$\begin{gathered} \mathrm{NaCl}\left(\mathrm{s}\right)\stackrel{{\mathrm{H}}_2\mathrm{O}}{\to }{\mathrm{Na}}^{+}\left(\mathrm{aq}\right)+{\mathrm{Cl}}^{-}\left(\mathrm{aq}\right) \\ (\mathrm{sodium}\mathrm{chloride})\left(\mathrm{cation}\right)\left(\mathrm{anion}\right) \end{gathered}$$