Basic equations for Entropy in Thermodynamics

2. ENTROPY
Reporter:
KIM BURNS

3. What is Entropy?
?

4. Entropy is the
measure of disorder.

7. PROBLEM
What is the change of entropy of 1 kg of ice that
is melted reversibly at 0°C and converted to
water at 0°C? The heat of fusion of water is
𝐿 𝑓 = 3.34 x 105 J/kg.

8. Entropy in Reversible
Processes.

9. Integrate for the entire
process

10. PROBLEM
One kilogram of water at 0°C is heated to
100°C. Compute its change in entropy. Assume
that the specific heat of water is constant at
4190 J/kg.K over this temperature range.

11. PROBLEM
A gas expands adiabatically and
reversibly. What is its change in entropy?

12. Entropy in Cyclic
Processes.

16. PROBLEM
A Carnot engine takes 2000 J of heat
from a reservoir at 500 K, does some
work, and discards some heat to reservoir
at 350 K. What is the total entropy change
during one cycle?

18. Entropy in Irreversible
Processes.

19. PROBLEM
Suppose 1.00 kg of water at 100°C is placed in
thermal contact with 1.00 kg of water at 0°C.
What is the total change in entropy? Assume
that the specific heat of water is constant at
4190 J/kg.K over its temperature range.

20. FIN!
Any questions?