Question

What is the formal charge of the centre most $O$ in ozone?

• A. -1
• B. \N
• C. 1
• D. 2

Answer 1

The correct option is C 1

Formal charge ($F.C$) on an atom in a Lewis structure = [total number of valence electrons in the free atom] - [total number of non bonding (lone pair) electrons] - $\frac{1}{2}\times$[total number of bonding(shared) electrons]

The structure of ozone is given below:

The formal charge of the central $O_1$ $=6-2-\frac{1}{2}\times 6=+1$
$F.C$ of the $O_2$ $=6-4-\frac{1}{2}\times 4=0$
$F.C$ of the $O_3$ $=6-6-\frac{1}{2}\times 2=-1$
The total charge of ozone is zero.