|
A small amount of heat Q flows out of a hot system A (at T = 350K) into a cold system B (at T = 250K). The overall [AB] system is thermally isolated from the rest of the universe. (Q is small enough that the temperature changes of the objects can be ignored.)
B.1 Do you expect the entropy change of the [AB] system to be positive, negative, or zero? Explain why you think so.
B.2 If Q = 0.5 J, mA = 1.2 kg, and mB = 0.6 kg, find the total change in the entropy of the [AB] system, ΔSAB. B.3 Suppose we let the two objects come to a thermal equilibrium. Do you expect the total Gibbs free energy of the [AB] system to have increased, decreased, or remained the same? Explain why you think so. |
 |
Ben Geller 8/16/12