Can you balance the equation using the oxidation states method MnO2+Al--->Mn+Al2O3?
1 Answer
You can find the steps for balancing redox equations at How do you balance redox equations by oxidation number method?
Your unbalanced equation is
MnO₂ + Al → Mn + Al₂O₃
Step 1. The oxidation numbers are:
Left hand side: Mn = +4; O = -2; Al = 0
Right hand side: Mn = 0; Al = +3; O = -2
Step 2. The changes in oxidation number are:
Mn: +4 → 0; Change = -4
Al: 0 → +3; Change = +3
Step 3. You need 3 atoms of Mn for every 4 atom of Al. This gives us total changes of +12 and -12.
Step 4. Insert coefficients to get these numbers.
3 MnO₂ + 4 Al → 3 Mn + 2 Al₂O₃
Every substance now has a coefficient. The equation should be balanced,
Step 5. Check that all atoms balance.
Left hand side: 3 Mn; 6 O; 4 Al
Right hand side: 3 Mn; 4 Al; 6 O
The balanced equation is
3MnO₂ + 4Al → 3Mn + 2Al₂O₃
