Question

Explain the reason of different length of equatorial and axial bond in the structure of $PC{l}_5$.

Answer 1

Two axial $P-Cl$ bonds are longer than three equatorial $P-Cl$ bonds as the axial bond pairs suffer more repulsion as compared to equatorial bond pairs. The bond angle between two equatorial $P-Cl$ bonds (${120}^0$) is greater than the bond angle between one axial and one equatorial $P-Cl$ bond (${90}^0$).