# What are the oxidation states of copper?

Jun 24, 2017

This is too broad a question, you can't memorize its oxidation states, per se, but you can rationalize what it is by memorizing the rules for common anions it usually bonds with!

#### Explanation:

For instance,

$C u S {O}_{4}$ — copper (II) sulfate
$x + \left(+ 6\right) + \left(- 8\right) = 0$

We know sulfate's charge is 2-, and we also memorize that an oxide anion has an oxidation state of 2-, unless its a peroxide in which case its charge is 1-, but that's another question!

So, solving this 8th grade algebra problem, we get:

$x - 2 = 0$
$x = 2$

Thus, in this particular compound, copper's oxidation state is 2+!

Jun 24, 2017

-2, +1, +2, +3, +4

#### Explanation:

Copper can have any of the above oxidation states, however +1 and +2 are the most common.

An example of a +2 oxidation state is CuO, where oxygen has an oxidation number of -2 and therefore copper has the oxidation number of +2 to balance out the molecule.

An example of a +1 oxidation state is Cu2O, where, once again, oxygen's oxidation state is -2 and so to balance out the molecule, each copper atom is +1.