Refrigerant-134a enters the expansion valve of a refrigeration system at 125 psia as a saturated liquid and leaves at 20 psia. Determine the temperature and internal energy changes across the valve. Use data from the steam tables.

An ammonia compressor has a 5% clearance volume and displacement rate of 80 l/s and pumps against a condensing temperature of 40°c. for two different temperatures of -10°c and 10°c, compute the mass flow rate of refrigerant assuming the clearance volumetric efficiency applies. discharge specific volume corresponding to-10°c and 10°c are 112.5 l/kg and 95 l/kg, respectively.