# How do you balance this redox reaction using the oxidation number method? Fe2+(aq) + MnO4–(aq) --> Fe3+(aq) + Mn2+(aq)

##### 1 Answer

**WARNING: This is a long answer.** The balanced equation is

#### Explanation:

You follow a series of steps in order:

- Identify the oxidation number of every atom.
- Determine the change in oxidation number for each atom that changes.
- Make the total increase in oxidation number equal to the total decrease in oxidation number.
- Place these numbers as coefficients in front of the formulas containing those atoms.
- Balance all remaining atoms other than
#"O"# and#"H"# . - Balance
#"O"# . - Balance
#"H"# . - Check that atoms and charges balance.

Here's how it works. Your unbalanced equation is

**1.** Identify the oxidation number of every atom.

Left hand side:

Right hand side:

**2.** Determine the change in oxidation number for each atom that changes.

**3.** Make the total increase in oxidation number equal to the total decrease in oxidation number.

We need 5 atoms of

**4.** Place these numbers as coefficients in front of the formulas containing those atoms.

**5.** Balance all remaining atoms other than

Done.

**6.** Balance

Add enough

We have 4

**7.** Balance

Add enough

We have 8

**8.** Check that atoms and charges balance.

On the left: :

On the right:

On the left:

On the right:

The balanced equation is