1. In analyzing real processes, when is the entropy balance helpful as opposed to merely being an additional equation with an additional unknown? 2. A “heat pump” is any cyclic device that uses work...

1. In analyzing real processes, when is the entropy balance helpful as opposed to merely being an additional equation with an additional unknown?

2. A “heat pump” is any cyclic device that uses work from the surroundings to move heat from a low-temperature reservoir to a high-temperature reservoir. For a specified amount of work, show that any real heat pump always removes less heat from the low-temperature reservoir than would a reversible heat pump between the same two reservoirs.