The thermodynamic criterion for spontaneity of a process in a system under constant volume and temperature… · ABC26PH0858
Subject: Physical Chemistry · Chapter: Thermodynamics · Topic: Thermodynamics – General · Exam: JAM 2001-2022 · Marks: 2 · Difficulty: Medium
The thermodynamic criterion for spontaneity of a process in a system under constant volume and temperature and in the absence of any work other than expansion work (if any) is
(a)change in entropy is positive
(b)change in enthalpy is negative
(c)change in Helmholtz free energy is negative
(d)change in Gibbs free energy is negative
Answer
Answer: C ✓ checked by 4AB · confidence high
The source book printed no answer; this one was worked out and checked — see the explanation.
Explanation
At constant T and V (no non-expansion work) the criterion is dA ≤ 0: the Helmholtz energy decreases in a spontaneous process.