Entropy(3) + Flashcards
What equation must all reversible cycles (including Carnot) running between two temperatures obey?
Hint: Sum of thermal energy
What equation do we expect for irreversible cycles?
Hint: Thermal energy, T
We now think of an arbitrary reversible process as a collection of many infinitely small reversible/Carnot processes operating between two temperatures.
This implies the the integral is independent of the path taken from state A to state B and that dQrev/T is an exact differential.
What is the integral of an exact differential? What is the equation for a general reversible cycle?
What is dS equal to?
What is the thermodynamic definition of entropy?
Proof dS is an exact differential
What is the Clausius inequality? Why does the inequality arise?
We know that for a reversible cycle, the cycle sums to 0. For an irreversible cycle the inequality arises dQirrev is less than dQrev.
Prove using the Clausius inequality that the reverse cycle eq is greater than the cycle for a irr cycle. Irr A to B, R B to A
Using the fact that the reversible cycle eq is greater than the irr cycle equation, and that the reversible cycle = dS, show that dQirr/T is less than dS. For a closed system dQ = 0 what does this mean?
What is the enthalpy change for heat, dQ leaving object 1, being passed to object 2?
As heat leaving object 1, dS for 1 is -ve.
What is dE equal to in terms of dS and dW
This enables us to get rid of the inexact differential (dQ with the dash line- not shown in image)
What are the heat capacities in terms of dS?
What is the equation of latent heat?
