Question

The formula charge on the nitrogen atoms from left to right the azide ion ${[N=N=N]}^{-}$ are:

• A. $+1,-1,-1$
• B. $-1,+1,-1$
• C. $-1,-1,+1$
• D. $-2,+1,0$

Answer 1

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

Formal charge= (Number of valence $e^{-}$ in free neutral atom) $-\frac{1}{2}$(Number of bonding $e^{-}$) $-$ (Number of non bonding $e^{-}$)

Using above equation we can calculate formal charge on

$N_I=5-2-4=-1$

$N_{II}=5-4-0=+1$

$N_{III}=5-2-4=-1$

$\underset{-1}{N_I}=\underset{+1}{N_{II}}=\underset{-1}{N_{III}}$