Question

Lead bromide undergoes electrolytic dissociation in the molten state but is a non-electrolyte in the solid state.

Answer 1

The ions present in PbBr₂ in solid state are held by strong electrostatic forces of attraction and hence cannot move under the influence of applied electric field.

OR

In solid state only tiny electrons can move under the influence of applied electric field (e.g., in metals). Ions are too big to move in solid state.