What is the oxidation number of Carbon in Na_2C_2O_4Na2C2O4?

1 Answer
Jun 23, 2016

Each carbon in oxalate ion has an oxidation number of +III+III.

Explanation:

The sum of the oxidation numbers of the constituent atoms equals the charge on the ion. Oxygen normally has an oxidation number of -IIII in its compounds, and it certainly does here.

Thus 2xxC_"Oxidation number"+4xx(-2)=-22×COxidation number+4×(2)=2 (Of course, -22 was the charge on the ion.) It does not take too much algebra to determine that C_"Oxidation number"=+IIICOxidation number=+III. Carbon here is almost fully oxidized.