question_answer

The bond angle in\[\text{N}{{\text{H}}_{3}}({{107.2}^{o}}).\]is smaller than \[\text{N}{{\text{H}}_{3}}({{107.2}^{o}}).\]This is because of

A)  large size of F compared to H

B)  large size of N compared to F

C)  opposite polarity of N in the two molecules

D)  small size of H compared to N

Correct Answer: C

Solution :

 In \[N{{F}_{3}},N\]is less electronegative as compared to F but in \[\text{N}{{\text{H}}_{\text{3}}}\text{.}\]it is more electronegative than H And in case of same central atom, as the electronegativity of other atoms increases bond angle decreases. Thus, bond angle in \[\text{N}{{\text{F}}_{\text{3}}}\]Is smaller than that in NH3 because of the difference in the polarity of N in these molecules.