Question

Which of the following has $p\pi -d\pi$ bonding?

• A. $N{O}_3^{-}$
• B. $S{O}_3^{2-}$
• C. $B{O}_3^{3-}$
• D. $C{O}_3^{2-}$

Answer 1

Answer: (B)

$N,B$, and $C$ are the elements of second period. These elements cannot form $p\pi -d\pi$ bonds as they do not possess $d-$ orbitals in their valence shell. On the other hand, $S$, an element of third period has, $3d$ orbitals and, hence, can form $p\pi -d\pi$ bonds with oxygen. In this bonding, the $d-$ orbitals of S overlap with the $p$ - orbitals of the $O$ atom.