# What is the oxidation number of carbon in CO2?

Oct 25, 2015

$4 +$

#### Explanation:

Since oxygen is in group 6 on the periodic table, its valency is $2 -$ and hence so is its oxidation number.
But there are 2 oxygen atoms for each carbon atom so the total negative charge due the oxygen is $4 -$
But since a molecule must have a net charge of zero in the free form, it implies that the oxidation number of the carbon atom must then be $+ 4$

Oct 25, 2015

Two oxygens and one carbon; carbon clearly has $I {V}^{+}$ oxidation state.

#### Explanation:

What is the oxidation state of carbon in methane, ethane, and carbon monoxide?