Question

Which molecule has trigonal pyramidal molecular geometry?

• A. $H_2$
• B. $O_2$
• C. $N_2$
• D. $C{O}_2$
• E. $N{H}_3$

Answer 1

Answer: (E)

$N{H}_3$

In $N{H}_3$ molecule, there is one lone pair on the Nitrogen atom and the Nitrogen atom forms three single bonds with Hydrogen atom. Thus it is $s{p}^3$ hybridized. So, technically it should be a tetrahedral with an angle of about ${109}^o$ . But because of the presence of a lone pair on Nitrogen atom, the angle changes to ${106}^o$ and the molecule adopts a trigonal pyramidal geometry.