Assertion :- Entropy of system increases for a spontaneous reactions.
Reason :- Enthalpy of reaction always decreases for spontaneous reaction.

Options

A. If both Assertion & Reason are True & the Reason is a correct explanation of the Assertion.
B. If both Assertion & Reason are True but Reason is not a correct explanation of the Assertion.
C. If Assertion is True but the Reason is False.
D. If both Assertion & Reason are false.

Answer

To analyze the given assertion and reason, we will break down the statements and evaluate their validity step by step.

### Step 1: Evaluate the Assertion
**Assertion:** Entropy of the system increases for spontaneous reactions.

- **Explanation:** The assertion states that the entropy of the system always increases during spontaneous reactions. However, this is not necessarily true. While many spontaneous processes do lead to an increase in entropy, there are cases where the entropy of the system may decrease, but the overall entropy of the universe (system + surroundings) still increases. Therefore, the assertion is **incorrect**.

### Step 2: Evaluate the Reason
**Reason:** Enthalpy of the reaction always decreases for spontaneous reactions.

- **Explanation:** The reason states that the enthalpy change (ΔH) for spontaneous reactions is always negative (indicating that the reaction is exothermic). This is also not true. Spontaneous reactions can be either exothermic (negative ΔH) or endothermic (positive ΔH). The spontaneity of a reaction is determined by the Gibbs free energy change (ΔG), which is given by the equation:

\[ ΔG = ΔH - TΔS \]

A reaction can be spontaneous even if ΔH is positive, provided that the term \(TΔS\) is sufficiently large to make ΔG negative. Therefore, the reason is also **incorrect**.

### Conclusion
Both the assertion and the reason are incorrect.

### Final Answer
Both the assertion and the reason are false.

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