Question

What is the hybridization of phosphorus in PCl5?

(a) sp^3

(b) sp^2

(c) sp^3d

(d) sp^3d^2

I got this question during an internship interview.

Origin of the question is P-Block Elements topic in chapter P-Block Elements of Chemistry – Class 12

Answer 1

Correct answer is (c) sp^3d

For explanation: In PCl5, phosphorus undergoes sp^3d hybridization and has trigonal bipyramidal geometry in gaseous and liquid states. It has three equatorial, P-Cl bonds and two axial, P-Cl bonds. Since two axial P-Cl bonds are repelled by three bond pairs while three equatorial bonds are repelled by two bond pairs, therefore, axial bonds are longer than equatorial bonds.