# What is the cofficient of Cr^2+?

##### 1 Answer

#### Explanation:

Start by finding what has been oxidized and what has bee reduced by inspecting the oxidation numbers:

In this case:

Is the oxidation

and

is the reduction

Start by balancing the half equations for oxygen by adding water:

(Only the reduction includes oxygen)

Now balance hydrogen by adding protons:

(again, only the reduction involves hydrogen)

Now balance each half-equation for charge by adding electrons to the more positive side:

And to equalize the electrons, multiply the whole half equation with the least electrons by an integer to equal the other half-equation in the number of electrons, thereby balancing the electrons on both sides of the equation:

Now combine everything and remove the electrons (as they in equal amounts on both sides they can be canceled in this step - otherwise just simplify as far as possible)

Now the equation is balanced and we can see that the coefficient to