JEE MAIN - Chemistry (2012 - No. 17)
The molecule having smallest bond angle is :
NCl3
AsCl3
SbCl3
PCl3
Explication
All the members form volatile halides of the type $$A{X_3}.$$ All halides are pyramidal in shape. The bond angle decreases on moving down the group due to decrease in bond pair-bond pair repulsion.
$$\eqalign{ & NC{L_3}\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,PC{l_3}\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,AsC{l^3} \cr & {107^ \circ }\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,{94^ \circ }\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,{92^ \circ } \cr} $$
$$\eqalign{ & NC{L_3}\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,PC{l_3}\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,AsC{l^3} \cr & {107^ \circ }\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,{94^ \circ }\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,{92^ \circ } \cr} $$