Question

Bond angle in PH₄⁺ is higher than that in PH₃ Why?

Answer 1

In PH₃ , P is sp³ hybridized. Three orbitals are involved in bonding with three hydrogen atoms and the fourth one contains a lone pair. As lone pair-bond pair repulsion is stronger than bond pair-bond pair repulsion, the tetrahedral shape associated with sp³ bonding is changed to pyramidal. PH₃ Combines with a proton to form PH₄⁺, in which the lone pair is absent. Due to the absence of lone pair in PH₄⁺, there is no lone pair-bond pair repulsion.

Hence, the bond angle in PH₄⁺ is higher than the bond angle in is PH₃

PH₄⁺

PH₃