Q.Ionic solids conduct electricity in molten state but not in solid state. Explain.

Electrical conduction needs mobile charge carriers. In the solid state the ions are held in fixed lattice positions by strong electrostatic forces and cannot move, so no current flows. In the molten state the lattice breaks down and the ions become free to move, …

Step 1 – Requirement for conduction.

Electrical conductivity requires charge carriers that can move — in ionic solids these are the ions themselves.

Step 2 – Solid state.

In the solid, the cations and anions are held in fixed positions in the crystal lattice by strong electrostatic (ionic) forces. They can only vibrate about mean positions and cannot migrate, so there are no mobile carriers and the solid does not conduct.

Step 3 – Molten state. …

State the carrier requirement (mobile ions), then contrast fixed lattice positions in the sol …

• Saying ionic solids conduct via free electrons — in ionic solids the carriers are ions, not electrons.
• Not explicitly stating that ions are fixed in the solid but mobile in the melt. …