Question

Which one of the following statements is correct?

• A. Hybrid orbitals do not form $\sigma$ bonds
• B. Lateral overlap of $p$ -orbitals or $p-$ and $d$ -orbitals produces $\pi$ -bonds
• C. The strength of bonds follows the order $\sigma_{p-p} < \sigma_{s-s} < \pi_{p-p}$
• D. s-orbitals do not form $\sigma$ bonds

Answer 1

Answer: (B)

(a) Hybridised orbitals show only head on overlapping and thus form only $\sigma$ bonds. They never form $\pi$ bonds.

(c) Head on overlapping is stronger than lateral or sideways overlapping. Therefore, the strength of bonds follows the order

$\underbrace{\pi_{p-p}}_{\text {lateral overlapping}}<\underbrace{\sigma_{s-s}<\sigma_{s-p}<\sigma_{p-p}}_{\text {head on overlapping of same shell }}$

(d) s-orbitals are spherically symmetrical and thus show only head on overlapping and form only $\sigma$ bonds.