# What is the oxidation number of chlorine?

##### 1 Answer
Nov 1, 2015

The oxidation number of chlorine can be -1, 0, +1, +3, +4, +5, or +7, depending on the substance containing the chlorine.

The most common oxidation numbers are -1 (as in $\text{HCl}$ and $\text{NaCl}$) and 0 (as in ${\text{Cl}}_{2}$).

But chlorine can have other oxidation numbers, for example:

• +1 in $\text{NaClO}$
• +3 in ${\text{NaClO}}_{2}$
• +4 in ${\text{ClO}}_{2}$
• +5 in ${\text{NaClO}}_{3}$
• +7 in ${\text{NaClO}}_{4}$