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gigi9
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Someone please give me a good explanation on how to "Balance Oxidation- Reduction Equations." Plz show me the steps and an example of how to do this type of equations. Thanks a lot.
An oxidation-reduction equation is a chemical equation that shows the transfer of electrons between reactants and products. It involves the oxidation of one substance (losing electrons) and the reduction of another substance (gaining electrons).
Balancing redox equations is important because it ensures that the number of atoms of each element and the total charge are the same on both sides of the equation. This follows the Law of Conservation of Mass and Charge, which states that matter and charge cannot be created or destroyed in a chemical reaction.
The steps for balancing redox equations are as follows:
1. Identify the reactants and products and determine the oxidation numbers of each element
2. Write half-equations for the oxidation and reduction reactions
3. Balance the atoms and charges in each half-equation
4. Balance the number of electrons transferred by multiplying the half-equations by appropriate coefficients
5. Add the two half-equations together and cancel out any common terms
6. Check that the atoms and charges are balanced on both sides of the equation
7. If necessary, add H+ or OH- ions to balance the hydrogen and oxygen atoms
8. Finally, neutralize any excess H+ or OH- ions by adding the appropriate number of H2O molecules.
Sure, let's take the reaction between permanganate ions (MnO4-) and iron (II) ions (Fe2+) in acidic solution to form manganese (II) ions (Mn2+) and iron (III) ions (Fe3+). The unbalanced equation is:
MnO4- + Fe2+ → Mn2+ + Fe3+
Step 1: Determine the oxidation numbers of each element
MnO4-: Mn = +7, O = -2
Fe2+: Fe = +2
Mn2+: Mn = +2
Fe3+: Fe = +3
Step 2: Write half-equations for the oxidation and reduction reactions
Oxidation: MnO4- → Mn2+
Reduction: Fe2+ → Fe3+
Step 3: Balance the atoms and charges in each half-equation
Oxidation: MnO4- → Mn2+ + 4H+ + 3e-
Reduction: 2Fe2+ → 2Fe3+ + 2e-
Step 4: Balance the number of electrons transferred by multiplying the half-equations by appropriate coefficients
Oxidation: 2MnO4- → 2Mn2+ + 8H+ + 6e-
Reduction: 3Fe2+ → 3Fe3+ + 3e-
Step 5: Add the two half-equations together and cancel out any common terms
2MnO4- + 3Fe2+ → 2Mn2+ + 3Fe3+ + 8H+ + 6e-
Step 6: Check that the atoms and charges are balanced on both sides of the equation
The atoms and charges are balanced, except for the hydrogen and oxygen atoms.
Step 7: Add H+ or OH- ions to balance the hydrogen and oxygen atoms
2MnO4- + 3Fe2+ + 8H+ → 2Mn2+ + 3Fe3+ + 4H2O + 6e-
Step 8: Neutralize any excess H+ or OH- ions
2MnO4- + 3Fe2+ + 8H+ + 6H+ → 2Mn2+ + 3Fe3+ + 4H2O
The final balanced equation is:
2MnO4- + 3Fe2+ + 8H+ → 2Mn2+ + 3Fe3+ + 4H2O
Some common mistakes to avoid when balancing redox equations include forgetting to check the