Question

Ionic solids do not conduct electricity, but will when the temperature is raised above the melting point. Which of the following explains why this is possible?

• A. The ionic solid dissociates and the resultant solution allows for conduction based on the solute-solvent interaction.
• B. The energy added to the system causes a breakdown in the crystalline structure which allows for free movement of the ions.
• C. The energy added to the system is actually absorbed in the form of an electrical charge, allowing the ionic compound to then conduct that charge.
• D. Ionic compounds can only conduct electricity when dissolved in water.

Answer 1

Answer: (B)

The energy added to the system causes a breakdown in the crystalline structure which allows for free movement of the ions.

When we supply energy to an ionic solid, the crystalline structure of the ionic solid fails and the ions are able to more freely in the liquid. This results in a charged liquid which can conduct electricity in its molten state.

$\to$ When the temperature is raised, ionic solids melts into molten pure ionic liquid, in which there is a free movement of ions and the conducts electricity.