# Oxidation number question

## Homework Statement

The problem is:

Find the oxidation number of each element in the compound: Pb(O)2

I said oxidation number of Pb = x, O = -1 since this is a peroxide, therefore oxidation number of Pb is plus 2. However, the solution manual says O is -2 and thus Pb is 2.

But elsewhere, for the problem BaO2, they say the oxidation number of O is -1 and Ba is +2.

I'm confused.

## The Attempt at a Solution

Borek
Mentor
PbO2 is not a peroxide.

epenguin
Homework Helper
Gold Member
Not clear whether it is the manual or you who is saying Pb in PbO2 is +2 but now hopefully not.

I have a vague recollection that lead dioxide did sometimes get improperly and misleadingly called "lead peroxide",
probably before chemical nomenclature was formalised and the name still hangs around.

James Pelezo
Gold Member
Borek is 100% right, it ain't a peroxide ... Hint: Oxy = -2, Calculate oxidation state of Pb.