014 10.0 points An engine using 1 mol of an ideal gas ini- tially at 18.2 L and 375 K performs a cycle consisting of four steps: 1) an isothermal expansion at 375 K from 18.2 L to 41.8 L ; 2) cooling at constant volume to 249 K ; 3) an isothermal compression to its original volume of 18.2 L: and 1) heating at constant volume to its original temperature of 375 K. Find its efficiency. Assume that the theat capacity is 21 J/K and the univer- sal gas constant is 0.08206 L - atm/mol/K - 8.314 .J/mol/K