1. The problem statement, all variables and given/known data A closed system contains 3 kg of R-134a at 10 °C and 90 kPa (state 1), and undergoes an internally reversible, isothermal process until the volume of the R-134a reaches 0.056 m3 (state 2). The system returns to state 1 by an irreversible process and the heat transfer for the return process is +3.2 kJ. Determine Q12, W12, W21 and the entropy change for each process. 2. Relevant equations 3. The attempt at a solution I do not know how to go about doing this. Any help will be appreciated. thanks.