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

$\underset{\text{lateral overlapping}}{\underbrace{{\pi }_{p-p}}}<\underset{\text{head on overlapping of same shell }}{\underbrace{{\sigma }_{s-s}<{\sigma }_{s-p}<{\sigma }_{p-p}}}$

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