A glass beaker of mass 400 g contains 500 g of water at 27 . The beaker is heated reversibly so that the temperature of the beaker and water rise gradually to 57 . Find the change in entropy of the beaker and water together.

A 0.50-kg piece of aluminum at 250 is dropped into 1.0 kg of water at 20 . After equilibrium is reached, what is the net entropy change of the system?

Give an example of a spontaneous process in which a system becomes less ordered and energy becomes less available to do work. What happens to the system's entropy in this process?

Which of the following is true for the entropy change of a system that undergoes a reversible, adiabatic process? (a) S 0 (b) S = 0 (c) S 0

The energy output of a heat pump is greater than the energy used to operate the pump. Why doesn't this statement violate the first law of thermodynamics?

In a diesel engine, the fuel is ignited without a spark plug. Instead, air in a cylinder is compressed adiabatically to a temperature above the ignition temperature of the fuel; at the point of maximum compression, the fuel is injected into the cylinder. Suppose that air at 20 C is taken into the cylinder at a volume V1 and then compressed adiabatically and quasi-statically to a temperature of 600 C and a volume V2 . If =1.4 , what is the ratio V1/V2 ? (Note: static. In an operating diesel engine, the compression is not quasi-

Two hundred joules of heat are removed from a heat at a temperature of 200 K. What is the entropy change of the reservoir?

An ice tray contains 500 g of liquid water at 0C. Calculate the change in entropy of the water as it freezes slowly and completely at 0C.

Check Your Understanding In Example 4.7, the spontaneous flow of heat from a hot object to a cold object results in a net increase in entropy of the universe. Discuss how this result can be related to an increase in disorder of the system.