Which of the following orders regarding the electronegativity of hybrid orbital of carbon is correct?

Which of the following orders regarding the electronegativity of hybrid orbital of carbon is correct?

1. sp > sp² > sp³

2. sp < sp² < sp³

3. sp > sp³ > sp²

sp < sp³ > sp2

The correct answer : option : (1)                                    sp > sp² > sp³

Explanation:

Electronegativity of hybrid orbitals depend on their s-character percentage.   Since s-orbitals are closer to the nucleus than p-orbitals,  higher s-character  increasing the electronegativity. 

        The sp hybrid orbitals have 50% s-character, sp² orbitals have 33.3% s-character and sp³ orbitals have 25% s-character.

Therefore, sp is most electronegative, followed by sp², then sp³. It also explains why the acidity increases in the order:

 HC≡CH (sp) > H₂C=CH₂ (sp²) > H₃C-CH₃ (sp³).