Entropy and the Second Law of Thermodynamics

1. Entropy and the Second Law of Thermodynamics Entropy Second Law

2. Reading Question In preparing for today’s class I spent about ___ hours reading, doing homework, or looking over my notes. • ½ • 1 • 1 ½ • 2 • 2 1/3 • 3 or more

3. Reading Question The second law of thermodynamics says that 1. the entropy of an isolated system never decreases. 2. heat never flows spontaneously from cold to hot. 3. the total thermal energy of an isolated system is constant. 4. both 1 and 2. 5. both 1 and 3.

4. Reading Question The second law of thermodynamics says that 1. the entropy of an isolated system never decreases. 2. heat never flows spontaneously from cold to hot. 3. the total thermal energy of an isolated system is constant. 4. both 1 and 2. 5. both 1 and 3.

5. Reading Question In general, 1. both microscopic and macroscopic processes are reversible. 2. both microscopic and macroscopic processes are irreversible. 3. microscopic processes are reversible and macroscopic processes are irreversible. 4. microscopic processes are irreversible and macroscopic processes are reversible.

6. Reading Question In general, 1. both microscopic and macroscopic processes are reversible. 2. both microscopic and macroscopic processes are irreversible. 3. microscopic processes are reversible and macroscopic processes are irreversible. 4. microscopic processes are irreversible and macroscopic processes are reversible.

7. The Second Law of Thermodynamics Thermal Interaction and Heat Heat is the energy transferred via collisions between more energetic (warmer) atoms on one side and the less energrtic (cooler) atoms on the other.

8. The Second Law of Thermodynamics Thermal Interaction and Heat

9. The Second Law of Thermodynamics Reversible and Irreversible Processes

10. The Second Law of Thermodynamics Reversible and Irreversible Processes

11. The Second Law of Thermodynamics Second Law of Thermodynamics: The entropy of an isolated system never decreases. The entropy either increases, until the system reaches equilibrium, or, if the system began in equilibrium, stays the same.

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20. Class Question Systems A and B are interacting thermally. At this instant of time, • 1. TA = TB. • 2. TA > TB. • TA < TB. • Not enough information.

21. Class Question Systems A and B are interacting thermally. At this instant of time, • 1. TA = TB. • 2. TA > TB. • TA < TB. • Not enough information.

22. Class Question Two identical boxes each contain 1,000,000 molecules. In box A, 750,000 molecules happen to be in the left half the box while 250,000 are in the right half. In box B. 499,900 molecules happen to be in the left half the box while 500,100 are in the right half. At this instant of time, 1. The entropy of box A is smaller than the entropy of box B. 2. The entropy of box A is equal to the entropy of box B. 3. The entropy of box A is larger than the entropy of box B.

23. Class Question Two identical boxes each contain 1,000,000 molecules. In box A, 750,000 molecules happen to be in the left half the box while 250,000 are in the right half. In box B. 499,900 molecules happen to be in the left half the box while 500,100 are in the right half. At this instant of time, 1. The entropy of box A is smaller than the entropy of box B. 2. The entropy of box A is equal to the entropy of box B. 3. The entropy of box A is larger than the entropy of box B.