Entropy in an irreversible cyclic process: behavior over one complete cycle Evaluate how the entropy of the system changes over a full irreversible cycle. Choose the correct statement.

Concept
Entropy (S) is a state function. For any complete cycle (start and end at the same state), the change in entropy of the system is zero: ΔS_system = 0, even if the processes are irreversible.

Important nuance
Clausius inequality gives ∮ δQ/T < 0 for an irreversible cycle, but this integral is not equal to ΔS_system over the cycle (which is zero by definition of a state function). The inequality reflects entropy generation in surroundings/universe, not a net change of the system after completing the loop.

Common pitfalls
Mixing up entropy of the system with entropy of the universe. The latter increases for overall spontaneous irreversible processes.

Final Answer
Remains constant over the cycle