Question

What is the entropy change for an ideal Carnot cycle? Explain your answer.

Answer 1

Entropy change for idea Carnot cycle is ZERO.

Because Carnot cycle consist of four process-

A) Reversible isothermal expansion

B) Reversible adiabatic Expansion

C) Reversible isothermal compression

D) Reversible adiabatic compression

And entropy change(∆S) = q_reversible/T

_{in B & D process entropy change is zero(adiabatic process (q) = 0)}

And in process A entropy change is positive as heat is absorbed

∆S = q/T is positive

And in C heat is released so entropy change is negative

∆S = - q/T

Both the entropy change is equal is magnitude so net entropy change is Zero.