WAEC Chemistry 2017 Paper

Concept:Electric conduction requires charged particles, like ions or electrons, that are free to move.Explanation:Solid $\mathrm{KCl}$ is an ionic compound made of $\mathrm{K^+}$ and $\mathrm{Cl^-}$ ions.In the solid state, these ions are held tightly in fixed lattice positions by strong electrostatic forces.Because the ions are immobile, they cannot move to carry electric current.Therefore, solid potassium chloride does not conduct electricity.Answer:Option B.