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A rigid, well-insulated tank contains a two-phase mixture consisting of 0.07 lb of saturated liquid water and 0.07 lb of saturated water vapor, initially at 20 lbf/in.2 A paddle wheel stirs the mixture until only saturated vapor remains in the tank. Kinetic and potential energy effects are negligible. For the water, determine the amount of energy transfer by work, in Btu

Five kilograms of water, initially a saturated vapor at 100 kPa, are cooled to saturated liquid while the pressure is maintained constant. Determine the work and heat transfer for the process, each in kJ. Show that the heat transfer equals the change in enthalpy of the water in this case.