Question

Arrange the following in the increasing order of electronegativity.

(a) sp^2 < sp < sp^3

(b) sp^3 < sp^2 < sp

(c) sp <  sp^2 < sp^3

(d) sp^3 < sp < sp^2

I had been asked this question during an interview.

This intriguing question originated from Tetravalence of Carbon: Shapes of Organic Compounds topic in division Organic Chemistry – Basic Principles and Technique of Chemistry – Class 11

Answer 1

Right answer is (b) sp^3 < sp^2 < sp

To elaborate: Greater the s-character of the hybrid orbitals, greater is the electronegativity. Sp hybrid orbitals have 50% s-character, thereby, greater electronegativity. Sp^3 has only 25% s-character and sp^2 hybrid orbitals have only 33% s-character, making sp the greatest electronegative orbital among them.