Question

Covalency and oxidation numbers of nitrogen in $N_2{O}_5$ is respectively

• A. 5, +5
• B. 4, +5
• C. 3, +3
• D. 3, +5

Answer 1

Answer: (B)

Covalency of $N$ is $4$ in $N_2{O}_5$ and its oxidation state is $+5$.

As clear from the structure of $N_2{O}_5$, covalency of nitrogen is 4 but the oxidation state is $+5$.
$x-2$
$N_2{O}_5$ is a neutral compound. Let the oxidation state of $N_2{O}_5$ be $x$.
$(2\times x)+(-2\times 5)=0$
$2x-10=10$
$x=5$