Question

Compare $x$ and $y$ bond lengths for the above given molecules.

• A. $x>y$
• B. $y>x$
• C. $x=y$
• D. None of these

Answer 1

The correct option is B $y>x$

In the first structure, more number of oxygen atoms are attached to $N$ than in the second structure. Oxygen is more electronegative than $N$. Hence, it will attract the bond pair electrons of $N-O$ bond towards itself. Hence, the positive charge on the $N$ atom in structure $I$ will be higher than in the structure $II$. hence, the $N$ atom will attract bond pair electrons of $N-O$ bond more strongly in $I$ than in $II$. Hence, the bond length $x$ will be shorter than the bond length $y$.
$x=175$ pm; $y=186.4$ pm.