AIIMS 2018 Chemistry Isothermal Processes Assertion Reason Question
Assertion : For an isothermal process involving an ideal gas Gibbs and Helmholtz free energy changes are equal, i. e. .
Reason : In an isothermal process for an ideal gas system both and are zero.
Both assertion and reason are correct and reason is the correct explanation for assertion.
Both assertion and reason are correct but reason is not the correct explanation for assertion.
Assertion is correct but reason is incorrect.
Assertion is incorrect but reason is correct.
Correct Answer
Detailed Explanation
In an isothermal process involving an ideal gas, both the Gibbs free energy (G) and Helmholtz free energy (A) changes are equal because the internal energy (ΔE) and enthalpy (ΔH) changes are zero, leading to the relationship ΔG = ΔH - TΔS and ΔA = ΔE - TΔS. Since ΔE and ΔH are zero, the changes in G and A are indeed equal, making both the assertion and reason correct, with the reason providing a valid explanation for the assertion.
Option B is incorrect because, while both statements are true, the reason does explain the assertion. Options C and D are incorrect as they misrepresent the correctness of the assertion and reason.
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