Question

What is a Redox reaction? Explain with a balanced chemical equation.

Hint:

Remember: OIL RIG rule — Oxidation Is Loss (of electrons), Reduction Is Gain (of electrons).

Answer 1

Concept: A Redox reaction (Reduction-Oxidation reaction) is a chemical reaction in which oxidation and reduction occur simultaneously. These reactions involve the transfer of electrons between substances. Definitions:

• Oxidation: Loss of electrons or addition of oxygen or removal of hydrogen.
• Reduction: Gain of electrons or removal of oxygen or addition of hydrogen.

Since electrons lost by one substance are gained by another, oxidation and reduction always occur together in a redox reaction. Example with Balanced Chemical Equation: Consider the reaction between zinc and copper(II) sulphate solution: \[ \text{Zn} + \text{CuSO}_4 \rightarrow \text{ZnSO}_4 + \text{Cu} \] Explanation:

• Zinc loses electrons to form zinc ions: \[ \text{Zn} \rightarrow \text{Zn}^{2+} + 2e^- \quad (\text{Oxidation}) \]
• Copper ions gain electrons to form copper metal: \[ \text{Cu}^{2+} + 2e^- \rightarrow \text{Cu} \quad (\text{Reduction}) \]

Thus, zinc is oxidized and copper ions are reduced. Conclusion: A redox reaction involves simultaneous oxidation and reduction through transfer of electrons. Such reactions are common in corrosion, respiration, photosynthesis, and electrochemical cells.