An engine using 1 mol of an ideal gas ini- tially at 23.5 L and 340 K performs a cycle consisting of four steps:
1) an isothermal expansion at 340 K from 23.5 L to 45.1 L;
2) cooling at constant volume to 225 K ;
3) an isothermal compression to its originalvolume of 23.5 L; and
4) heating at constant volume to its original
temperature of 340 K .
Find its efficiency. 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. Give your answer in the form of a percentage.