# How can I draw the Lewis structure for ClO2-?

Jul 15, 2014

Here's how I would do it.

#### Explanation:

You can find the procedure here.

For $\text{ClO"_2^"-", "Cl}$ is the less electronegative atom. So, $\text{Cl}$ is the central atom

The skeleton structure is $\text{O-Cl-O} .$

The trial structure is

You have 20 valence electrons in your trial structure.

The valence electrons you have available are: "1 Cl + 2 O + 1 e" = 1×7 + 2×6 + 1 = 20.

Hence, the trial structure has the correct number of electrons.

The formal charge on each atom is:

$\text{Cl" = 7 - 4 - ½(4) = +1; "O" = 6 – 6 - ½(2) = "-1}$

Every atom has a formal charge.

We can reduce the number of formal charges by moving a lone pair of electrons from $\text{O}$ to form a $\text{Cl=O}$ double bond.

This gives us two new structures in which one $\text{O}$ atom has $\text{FC = -1}$ and the other atoms have $\text{FC = 0}$:

The actual structure is nine of these. Rather, it is a resonance hybrid of them both