Problem 3: (2.5 Points)

Example 7.19 (a) 1 kg water at 0°C is brought into

contact with a heat reservoir at 90°C. When water has

reached 90°C, find

(i) Entropy change of water,

(ii) Entropy change of the reservoir,

(iii) Entropy change of the universe.

(b) If water is heated from 0°C to 90°C by first bringing

it in contact with the reservoir at 40°C and then with a

reservoir at 90°C, what will be the entropy change of the

universe?

(c) Explain how water might be heated from 0°C to 90°C

with almost no change in entropy of the universe?