Which of the two ions from the list given below have the geometry that is explained by the same hybridization…

Which of the two ions from the list given below have the geometry that is explained by the same hybridization of orbitals: $NO_2^-$, $NO_3^-$, $NH_2^-$, $NH_4^+$, $SCN^-$?
A $NO_2^-$ and $NH_2^-$
B $NO_2^-$ and $NO_3^-$
C $NH_4^+$ and $NO_3^-$
D $SCN^-$ and $NH_2^-$

Detailed Solution

Find the steric number (σ bonds + lone pairs) of the central atom in each ion.
$NO_2^-$: N has 2 σ bonds + 1 lone pair = 3, so $sp^2$.
$NO_3^-$: N has 3 σ bonds + 0 lone pairs = 3, so $sp^2$.
$NH_2^-$: N has 2 σ bonds + 2 lone pairs = 4, so $sp^3$.
$NH_4^+$: N has 4 σ bonds + 0 lone pairs = 4, so $sp^3$.
$SCN^-$: C has 2 σ bonds + 0 lone pairs = 2, so sp.
Among the given pairs, only $NO_2^-$ and $NO_3^-$ have the same hybridisation ($sp^2$).

Hybridisation in past papers

4 questions from this chapter have appeared across 2 exam years.

Keep going

Practise Hybridisation All 4 questions This chapter in 2011 AIPMT-PRE