. PH3 exists but PH5 does not exist while
- In PH3 there is no hybridization.
- In PH5 there is no d-orbital contraction.
- PCl3 and PCl5 both exist as PCl3 and PCl5 both can expand their covalency, so hybridization is possible in both.
So, The correct option is C.
PH3 exists but PH5 does not exist while both PCl3 and PCl5 exist.
Reason- PH3 has sp3 hybridization.
PH3 exist but PH5 does not exist while both PCl3 and PCl5 exist.
The Assertion is true, Reason is false.