3 An ideal monatomic gas, consisting of 2.8 mol of
volume 8.6x10-2 m² , expands adiabatically. The
initial and final temperatures are 75 °C and -85
°C.
What is the final volume of the gas ?

6–43 a food department is kept at 2128c by a refrigerator in an environment at 308c. the total heat gain to the food department is estimated to be 3300 kj/h and the heat rejection in the condenser is 4800 kj/h. determine the power input to the compressor, in kw and the cop of the refrigerator.