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Assertion (A): May endothermic reaction...

Assertion (A): May endothermic reactions that are not spontaneous at room temperature become spontaneous at high temperature.
Reason (R ) : Entropy of the system increases with increase in temperature.

A

If both the statements are TRUE and STATEMENT-2 is the correct explanation of STATEMENT-11

B

If both the statements are TRUE but STATEMENT-2 is NOT the correct explanation of STATEMENT-11

C

If STATEMENT-1 is TRUE and STATEMENT-2 is FALSE

D

If STATEMENT-1 is FALSE and STATEMENT-2 is TRUE

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AI Generated Solution

The correct Answer is:
To analyze the assertion and reason provided in the question, we can break down the concepts involved in thermodynamics, particularly focusing on Gibbs free energy and entropy. ### Step-by-Step Solution: 1. **Understanding the Assertion (A)**: - The assertion states that "may endothermic reactions that are not spontaneous at room temperature become spontaneous at high temperature." - An endothermic reaction is characterized by a positive change in enthalpy (ΔH > 0). For a reaction to be spontaneous, the change in Gibbs free energy (ΔG) must be negative (ΔG < 0). 2. **Gibbs Free Energy Equation**: - The relationship between Gibbs free energy, enthalpy, and entropy is given by the equation: \[ \Delta G = \Delta H - T \Delta S \] - Here, ΔS is the change in entropy. For an endothermic reaction, ΔH is positive. 3. **Conditions for Spontaneity**: - For an endothermic reaction to become spontaneous at high temperatures, we need to consider the term \(T \Delta S\). - If ΔS is positive (which is often the case for endothermic reactions that lead to increased disorder), increasing the temperature (T) will increase the value of \(T \Delta S\). 4. **Making ΔG Negative**: - As temperature increases, the term \(T \Delta S\) becomes larger and more negative (since ΔH is positive). - Therefore, at sufficiently high temperatures, it is possible for ΔG to become negative, making the reaction spontaneous. 5. **Conclusion on Assertion**: - Thus, the assertion is true: endothermic reactions that are non-spontaneous at room temperature may become spontaneous at higher temperatures. 6. **Understanding the Reason (R)**: - The reason states that "entropy of the system increases with increase in temperature." - While it is true that the entropy of a system tends to increase with temperature, this statement does not specifically explain why endothermic reactions can become spontaneous at high temperatures. 7. **Correct Explanation**: - The correct explanation involves the relationship between ΔH, ΔS, and temperature in the Gibbs free energy equation, rather than a general statement about entropy increasing with temperature. 8. **Conclusion on Reason**: - Therefore, while the reason is true, it does not correctly explain the assertion. ### Final Answer: - Assertion (A) is true, while Reason (R) is true but does not provide the correct explanation for the assertion.
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