- #1
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.
Originally posted by arcnets
gigi9,
photosynthesis might be a good example. Let's start from
H2O + CO2 -> C6H12O6 + O2.
First step, let's add what we have.
Left-hand side: 2H + 3O + 1C.
Right-hand side: 12H + 8O + 6C. So the formula is not balanced.
As a first step, we should look for an element that appears only in one component on each side. This is carbon. So, to balance carbon, we have to use 6 molecules of carbon dioxide:
H2O + 6CO2 -> C6H12O6 + O2.
Let's add what we have.
Left-hand side: 2H + 13O + 6C.
Right-hand side: 12H + 8O + 6C.
Is there another element which appears only once on each side? Yes, hydrogen! So we better use 6 molecules of water:
6H2O + 6CO2 -> C6H12O6 + O2.
Left-hand side: 12H + 18O + 6C.
Right-hand side: 12H + 8O + 6C.
We can balance this by adding more oxygen on the RHS:
6H2O + 6CO2 -> C6H12O6 + 6O2.
Now it's balanced.
Oxidation-reduction reaction, also known as redox reaction, is a type of chemical reaction that involves the transfer of electrons between reactants. In this reaction, one reactant loses electrons (oxidation) while the other gains electrons (reduction).
Balancing redox equations is important because it ensures that the number of atoms and the charge are conserved on both sides of the equation. This allows us to accurately predict the products of the reaction and determine the stoichiometry of the reaction.
The steps involved in balancing a redox equation are:
1. Identify the reactants and products
2. Separate the reaction into two half-reactions, one for oxidation and one for reduction
3. Balance the atoms other than hydrogen and oxygen in each half-reaction
4. Balance the oxygen atoms by adding water molecules
5. Balance the hydrogen atoms by adding hydrogen ions
6. Balance the charges by adding electrons
7. Make the total number of electrons equal in both half-reactions by multiplying one or both of the half-reactions
8. Combine the two half-reactions and cancel out any common terms
9. Double-check to ensure that all the atoms and charges are balanced.
Yes, for example, let's balance the following redox equation:
Fe + HCl → FeCl2 + H2
1. Separate the reaction into two half-reactions:
Oxidation: Fe → Fe3+
Reduction: HCl → H+ + Cl-
2. Balance the atoms (other than hydrogen and oxygen) in each half-reaction:
Oxidation: Fe → Fe3+
Reduction: 2HCl → 2H+ + 2Cl-
3. Balance the oxygen atoms by adding water molecules:
Oxidation: Fe → Fe3+
Reduction: 2HCl → 2H+ + 2Cl- + 2H2O
4. Balance the hydrogen atoms by adding hydrogen ions:
Oxidation: Fe → Fe3+
Reduction: 2HCl + 2H+ → 2H+ + 2Cl- + 2H2O
5. Balance the charges by adding electrons:
Oxidation: Fe → Fe3+ + 3e-
Reduction: 2HCl + 2H+ + 2e- → 2H+ + 2Cl- + 2H2O
6. Make the number of electrons equal in both half-reactions by multiplying the oxidation half-reaction by 2:
2Fe → 2Fe3+ + 6e-
Reduction: 2HCl + 2H+ + 2e- → 2H+ + 2Cl- + 2H2O
7. Combine the two half-reactions and cancel out any common terms:
2Fe + 2HCl → 2FeCl2 + 2H2
8. Double-check to ensure that all the atoms and charges are balanced.
Fe + 2HCl → FeCl2 + H2
Yes, there are a few shortcuts that can make balancing redox equations easier. Some of these tricks include:<