Chapter 18, Problem 54PCE

Predict/Explain (a) If the temperature in the kitchen is decreased, is the cost (work needed) to freeze a dozen ice cubes greater than, less than, or equal to what it was before the kitchen was cooled? (b) Choose the best explanation from among the following:

1. I.            The difference in temperature between the inside and the outside of the refrigerator is decreased, and hence less work is required to freeze the ice.
2. II.            The same amount of ice is frozen in either case, which requires the same amount of heat to be removed and hence the same amount of work.
3. III.            Cooling the kitchen means that the refrigerator must do more work, both to freeze the ice cubes and to warm the kitchen.