Insert correct coefficients it is a redox reaction
Al2+MnO2=Al2O3+Mn
Al2???
To determine the correct coefficients for balancing the redox reaction between Al and MnO2 (manganese dioxide), we need to follow a step-by-step process:
1. Write down the unbalanced equation:
Al2 + MnO2 → Al2O3 + Mn
2. Assign oxidation numbers to each element:
Since there is no charge indicated for Al, we can assume it has an oxidation number of 0.
The oxidation number of O is always -2.
The sum of the oxidation numbers in a compound should be zero.
So, let's assign the oxidation numbers:
Al: 0
Mn: x
O: -2
3. Identify the elements undergoing changes in oxidation state:
In this case, we can see that Al goes from 0 to +3, while Mn goes from +4 to 0.
4. Balance the atoms that are not involved in the redox reaction:
In this reaction, we only need to balance oxygen and hydrogen, but there are none present.
5. Balance the atoms involved in the redox reaction:
Start by balancing the element that is changing its oxidation state with the highest oxidation number, in this case, Mn.
Mn: +4 → 0, it loses 4 electrons.
MnO2 + 4e- → Mn
Now, the equation becomes:
Al2 + MnO2 + 4e- → Al2O3 + Mn
6. Balance the electrons on the other side of the equation:
We can see that the total number of electrons lost (4e-) must be equal to the number of electrons gained. In this case, the coefficient for Al2O3 will be 4 since Al has an oxidation state of +3.
Al2 + MnO2 + 4e- → Al2O3 + Mn
7. Balance the remaining atoms:
The equation is now unbalanced in terms of aluminum (Al) atoms. Since we have 2 Al atoms on the left side, we need to put a coefficient of 2 in front of Al2O3.
Al2 + MnO2 + 4e- → 2Al2O3 + Mn
8. Check the overall balance of atoms and charges:
- Aluminum: 2 on both sides
- Manganese: 1 on both sides
- Oxygen: 6 on both sides
- Charges: 0 on both sides
The balanced equation is:
2Al2 + MnO2 + 4e- → 2Al2O3 + Mn