"in PCl5,axial two P-Cl bonds are longer than equatorial three P-Cl bond due to repulsion between 3 equatorial bond pair of electron and 2 axial bond pair of electron."i can not understand it,please explain in simple terms.
This means that 5 atoms of Cl can not be located around one atom of P and still have 5 equal bonds. This sterically impossible, because the size of five atoms is too large to be located around a& P equally. Therefore, some ties are longer and others are shorter.