A mass of \(10 \mathrm{~kg}\) of water at \(0^{\circ} \mathrm{C}\) is brought into contact with a large heat reservoir at \(100{ }^{\circ} \mathrm{C}\).

a. When the water has reached \(100^{\circ} \mathrm{C}\) what has been

- the change of entropy of the water;

- the change of entropy of the reservoir;

- the change of entropy of the universe?

b. If the water had been heated from 0 to \(100{ }^{\circ} \mathrm{C}\) by first bringing it into contact with a reservoir at \(30^{\circ} \mathrm{C}\) and then a reservoir of \(100^{\circ} \mathrm{C}\), what would have been the change in the entropy of the universe?

c. Explain how the water could have been heated to give no change in the entropy of the universe.

[13.11 kJ/kg K; \(-11.26 \mathrm{~kJ} / \mathrm{kg} \mathrm{K;} 1.85 \mathrm{~kJ} / \mathrm{kg} \mathrm{K;} 1.070 \mathrm{~kJ} / \mathrm{kg} \mathrm{K}\); infinite number of reservoirs]