(a) Step 1. The gas is expanded isothermally to 0.25MPa, absorbing a quantity of heat QH1; Step 2. The gas is cooled at constant volume to 375K; Step 3. The gas is compressed isothermally to the initial volume; Step 4. The gas is heated to the initial state at constant volume requiring heat transferQH2. Calculate U,Q,WEC for each step and for the cycle. Also calculate the thermal efficiency that is the ratio of total work obtained to heat furnished, (QH1+QH2)WEC,cycle. 3 One mole of propane gas held within a piston/cylinder, at an initial condition of 550 K and 4.5 MPa, undergoes the following reversible steps. Use a temperatureindependent heat capacity of CP=74J/(molK)