Question

In the following structure of $C{O}_3^{2-}$ formal charges on carbon atom, double bonded oxygen atom and single bonded oxygen atom are respectively

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

Answer 1

Answer: (C)

Lewis structure of $C{O}_3^{2-}$ ion is

Formal charge = [valence electrons - lone pair electrons
$-\frac{1}{2}$ bonding electrons]
Formal charge on carbon atom$=4-\frac{1}{2}\times 8=0$
Formal charge on double bonded $O$ atom $=6-4-\frac{1}{2}\times 4$
$=0$
Formal charge on single bonded $O$ atom
$=6-6-\frac{1}{2}\times 2$
$=-1$