Question

Find the oxidation state of the halogen in the following compound:

Cl₂O

Answer 1

Let the oxidation state of Cl be x.

Oxygen (O) always has an oxidation state of –2 (except in peroxides or with fluorine, which is not the case here).

The formula is Cl₂O, so:

2 chlorine atoms → 2x

1 oxygen atom → –2

Total charge on the molecule = 0 (it’s neutral)

So the equation is:

2x + (−2) = 0

2x − 2 = 0

2x = +2

⇒ x = +1

∴ The oxidation state of halogen in Cl₂O is +1.