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014 10.0 points An engine using 1 mol of an ideal gas ini- tially at 15.8 L and 267 K performs a cycle consisting of four steps: 1) an isothermal expansion at 267 K from 15.8 L to 30.6 L ; 2) cooling at constant volume to 96 K ; 3) an isothermal compression to its original volume of 15.8 L; and 4) heating at constant volume to its original temperature of 267 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. 015 (part 1 of 3) 10.0 points