# Entropy changes of pure substances heat 730c is a

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Unformatted text preview: a enters the coils of the evaporator of a refrigeration system as a saturated liquid–vapor mixture at a pressure of 200 kPa. The refrigerant absorbs 120 kJ of heat from the cooled space, which is maintained at 5°C, and leaves as saturated vapor at the same pressure. Determine (a) the entropy change of the refrigerant, (b) the entropy change of the cooled space, and (c) the total entropy change for this process. Entropy Changes of Pure Substances Heat 7–30C Is a process that is internally reversible and adiabatic necessarily isentropic? Explain. IDEAL GAS 40°C 30°C 200 kJ FIGURE P7–24 7–25 Air is compressed by a 12-kW compressor from P1 to P2. The air temperature is maintained constant at 25°C during this process as a result of heat transfer to the surrounding medium at 10°C. Determine the rate of entropy change of the air. State the assumptions made in solving this problem. Answer: 0.0403 kW/K 7–26 During the isothermal heat addition process of a Carnot cycle, 900 kJ of heat is added to the working fluid from a so...
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## This document was uploaded on 11/28/2012.

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