In a refrigerator, ammonia enters a condenser at 50C and leaves at a saturation temperature of 0C at the same pressure. It is then throttled and the temperature drops to -10C. Finally, it passes through an evaporator at a constant pressure and leaves at -10C in a dry saturated condition. Determine: (a) the energy given up by the condenser (b) the dryness fraction after the throttling process (c) the energy absorbed by the evaporator