One mole of methane gas held within a piston/cylinder, at an initial condition of 600K and 5 MPa, undergoes the following reversible steps. Use a temperature-independent heat capacity of Cp=44J/mol-K.
Step 1: The gas is expanded to 3.92 MPa isothermally, absorbing a quantity of heat QH1.
Step 2: The gas is expanded adiabatically to 0.1 MPa. Step 3: The gas is compressed isothermally to 0.128 MPa. Step 4: The gas is compressed adiabatically to the initial state. Calculate dU,Q,Wec for each step and for the cycle. Also calculate the thermal efficiency for the cycle.