Discuss the importance of balancing redox react... - SS2 Chemistry Electrochemistry Question

Balancing redox reactions is crucial to ensure that the number of electrons gained and lost in the oxidation and reduction processes is equal. This balancing is achieved by adjusting the coefficients of the reactants and products in the chemical equation. Oxidation numbers play a significant role in balancing redox reactions by tracking electron transfers.

To balance a redox reaction, the following steps are generally followed:

1.    Assign oxidation numbers to all atoms in the reaction.

2.    Identify the species that undergo oxidation and reduction.

3.    Write half-reactions for the oxidation and reduction processes, showing the changes in oxidation numbers.

4.    Balance the atoms (except hydrogen and oxygen) in each half-reaction by adding water molecules (H2O) or hydroxide ions (OH-) as needed.

5.    Balance the charges in each half-reaction by adding electrons (e-).

6.    Multiply each half-reaction by appropriate coefficients to equalise the number of electrons gained and lost.

7.    Combine the balanced half-reactions to obtain the balanced overall redox equation.

Example of a balanced redox reaction using oxidation numbers:

In the reaction: Cl2 + 2NaBr → 2NaCl + Br2

●     Chlorine (Cl) has an oxidation number of 0 in Cl2 and -1 in NaCl.

●     Bromine (Br) has an oxidation number of -1 in NaBr and 0 in Br2.

Half-reactions:

Oxidation: Cl2 → 2Cl- (loses 2 electrons)

Reduction: 2Br- → Br2 + 2e- (gains 2 electrons)

Balanced equation:

Cl2 + 2NaBr → 2NaCl + Br2

By assigning oxidation numbers and following the steps for balancing redox reactions, we can achieve a balanced equation that satisfies the conservation of mass and charge.