Oxygen gas at 3.0 atm and 30°C is diffusing through a membrane of Polyethylene 3.0 mm thick and Nylon 7.0 mm thick in series. The partial pressure at the other side of the
two films is 0.5 atm, assuming no other resistances, calculate the flux NA at steady state.

Refrigerant-134a enters the compressor of a refrigerator as superheated vapor at 0.14 mpa and -10°c at a rate of 0.05 ka/s and leaves at 0.8 mpa and 50°c. the refrigerant is cooied in the condenser to 0.72 mpa and 26'c. it is then throttled to 0.15 mpa. sketch the t-s diagram for the system and evaluate: 6) the rate of heat removai from the refrigerated space (kw), it) the power input to the compressor (kw), ii) the isentropic efficiency of the compressor (%), and iv) the cop of the refrigerator.