Calculate the formal charge on each atoms in nitrite ion.

Explanation

Lewis structure of `NO_(2)^(Θ)` ion is
(a) `FC` on N-atom:
No. of valence `e^(-)` on N-atom `=5e^(-')s`
Lone pair (lp) electrons on N-atom `=1 xx 2 =2 e^(-')s`
No. of bonding `e^(-')s = 3 xx 2 =6 e^(-')s`
Hence `FC` on N-atom `=5 -2-(1)/(2) (6) =0`
(b) `FC` on O-atom (marked 1)
No.of valence `e^(-')s` on O-atom ` 6e^(-')s`
Lone pair (lp) electrons on O-atom `=2 xx 2 =4e^(-')s`
No. of bonds O-atom forms `=2`
No . of bonding `e^(-')s =2 xx 2 =4e^(-')s`
Hence `FC` on O-atom (marked 1) `=6 -4- (1)/(2) (4) = 0`
(c ) `FC` on O-atom (marked2) No of valence `e^(-)` on O-atom `=6 e^(-')s`
Lone pair (lp) electrons on O-atom `=3 xx 2 =6`
No of bonds O-atom forms `=1`
No of bonding `e^(-')s =1 xx 2 =2e^(-')s`
Hence `FC` on O-atom (marked2) `=6 - 6- (1)/(2) (2) = -1`
(d) Sum of `FC' s = ` Net charge of `NO_(2)^(Θ) = -1`
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