Question

Give reason for the following:

PCl₅ is ionic in the solid state.

Answer 1

1. In solid state, PCl₅ exists as [PCl₄]⁺ and [PCl₆]⁻ ions.
2. The formation of these ions leads to ionic bonding due to electrostatic forces between them.
3. This ionic structure provides greater stability in the solid form.
4. Hence, PCl₅ behaves as an ionic compound in the solid state, unlike the covalent molecular form in the gaseous state.