# What is the oxidation state of chlorine in KClO3?

Jul 14, 2014

$+ 5$

#### Explanation:

Excellent question! I love oxidation state questions.

First, let's look at the $\text{K}$ (potassium). In an ionic compound, the potassium's oxidation state is always $+ 1$.

Next, let's look at the chlorate , ${\text{ClO}}_{3}^{-}$. The charge on the polyatomic ion is $- 1$. You may be asking yourself, how do I know its charge will be $- 1$?

Since the entire compound ${\text{KClO}}_{3}$ has a charge of $0$ and the $\text{K}$ will have a charge of $+ 1$, the ${\text{ClO}}_{3}$ must balance the $\text{K}$'s $+ 1$ in the form of $- 1$ for a net charge of $0$.

When oxygen is with another element that is less electronegative than it is, the charge on the oxygen is $- 2$. There are $3$ oxygen atoms in the chlorate ion, for a total of $- 6$ charge on the total of the $3$ oxygen atoms.

Thus, $\text{charge of Cl}$ $+ \left(- 6\right) = - 1$. That means that the charge on chlorine in potassium chlorate is $+ 5$.

Have a great day!!