2.3 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). (b) Step 1. The gas is expanded 3.023MPa isothermally, absorbing a quantity of heat QH1; Step 2. The gas is expanded adiabatically to 0.1MPa; Step 3. The gas is compressed isothermally to 0.128MPa; Step 4. The gas is compressed adiabatically to the initial state. Calculate U,Q,WEC for each step and for the cycle. Also calculate the thermal efficiency for the cycle, (QH1)WEC,cyle