Question

How many lone pairs are present in the $N_2{O}_4$?

Answer 1

The Lewis structure of $N_2{O}_4$ is as shown.

Here one $N$ atom is attached to another $N-$atom by single bond. Both $N$ atoms form $1$ double bond with $O$ atom and again both $N$ atoms is attached $O-$ atom by single bond.

Here the number of lone pairs $=2\times (2+3)=10$