Question

The formal charges of $N_{\left(1\right)},N_{\left(2\right)}$ and O atoms in $:\ddot{\begin{array}{c}N\\ 1\end{array}}=\begin{array}{c}N\\ 2\end{array}=\ddot{O}:$ are respectively.

• A. +1, -1, 0
• B. -1, +1, 0
• C. +1, +1, 0
• D. -1, -1, 0

Answer 1

The correct option is B -1, +1, 0

Formal charge = [Total number of valence electrons in the free atom]
-[Total number of non-bonding (lone pair) electrons] - $\frac{1}{2}$ [Total number of bonding (shared) electrons]
In $:\ddot{\begin{array}{c}N\\ \left(1\right)\end{array}}=\begin{array}{c}N\\ \left(2\right)\end{array}=\ddot{O}:$ structure the formal charge on... the end N atom marked 1,
$=5-4-\frac{1}{2}\left(4\right)=5-4-2=-1$
the central N atom marked 2,
$=5-0-\frac{1}{2}\left(8\right)=5-4=+1$
the end O atom,
$=6-4-\frac{1}{2}\left(4\right)=6-6=0$