An engine using 1 mol of an ideal gas ini-
tially at 22.3 L and 454 K performs a cycle
consisting of four steps:
1) an isothermal expansion at 454 K from
22.3 L to 40 L;
2) cooling at constant volume to 270 K ;
3) an isothermal compression to its original
volume of 22.3 L; and
4) heating at constant volume to its original
temperature of 454 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.