Question

In the following electron-dot structure, calculate the formal charge from left to right nitrogen atom (shown).

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

Answer 1

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

Formal charge $=$ Total number of valence electrons $-$ Total number of nonbonding electrons $-\frac{1}{2}\times$ Total number of bonding electrons.
As for given structure,

For 1st and 3rd nitrogen atom
Formal charge $=5-4-\frac{1}{2}\times 4=-1$

For middle nitrogen atom
Formal charge $=5-0-\frac{1}{2}\times 8=+1$