Question

Can you balance the equation using the oxidation states method MnO2+Al--->Mn+Al2O3?

Answer 1

Answer:

Explanation:

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