NEETChemistryThermodynamics (C)
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): For the reaction N ₂ (g) + 3 H ₂ (g) 2 NH ₃ (g) , the value of G becomes more positive as temperature increases. Reason (R): The synthesis of ammonia from its elements is an exothermic process. In the light of the above statements, choose the most appropriate answer from the options given below:
Options
- ABoth (A) and (R) are true and (R) is the correct explanation of (A)
- BBoth (A) and (R) are true but (R) is not the correct explanation of (A)
- C(A) is true but (R) is false
- D(A) is false but (R) is true
Correct answer
B. Both (A) and (R) are true but (R) is not the correct explanation of (A)
Step-by-step solution
Assertion (A) is true: For the Haber process, n_g = 2 - 4 = -2 . Since the number of gaseous moles decreases, the entropy change is negative ( S Reason (R) is true: The synthesis of ammonia is an exothermic process ( H However, the exothermic nature of the reaction explains why it is spontaneous at low temperatures, but it does not explain why G becomes more positive as temperature increases. The correct explanation for the temperature dependence is the negative entropy change ( S Answer: Both (A) and (R) are true