014 10.0 points An engine using 1 mol of an ideal gas ini tially at 20.4 L and 296 K performs a cycle consisting of four steps: 1) an isothermal expansion at 296 K from 20.4 L to 38.1 L; 2) cooling at constant volume to 140 K ; 3) an isothermal compression to its original volume of 20.4 L; and 4) heating at constant volume to its original temperature of 296 K. Find its efciency. Assume that the heat capacity is 21 J / K and the univer- sal gas constant is 0.08206 L - atm/mol/K = 8.314 J/mol/K. 021 10.0 points The interior of a refrigerator has a surface area of 4.1 m2. It is insulated by a 1.8 cm thick material that has a thermal conductiv ity of 0.0161 J/m - s - C. The ratio ofthe heat extracted from the interior to the work done by the motor is 8.5% of the theoretical maxi mum. The temperature of the room is 40.2'3C, and the temperature inside the refrigerator is 92C. Determine the power required to run the compressor. Answer in units of W