Balancing equations in acidic conditions

Spectator ions can be balanced separately but aren't...

oxidised or reduced

Acidic conditions:

H2O and H+

Alkali conditions:

H2O and OH-

Steps for acidic conditions:

1. Balance

2. Write oxidation states + electrons gained/lost

3. Add H+ and H2O

4. Balance electrons in half equations

5. Combine half equations -> .. ...?

ionic equation

Example:

MnO₄⁻ → Mn²⁺

?e⁻ + 8H⁺, 4H₂O

5

Example:

Cr₂O₇²⁻ → Cr³⁺

?e⁻ + 14H⁺, 7H₂O

6

Example:

Fe²⁺ → Fe³⁺

?e⁻?

1