1. The problem statement, all variables and given/known data A mass of 0.45 kg of a perfect gas with a ratio of specific heats of 1.41 expands isentropically by means of a reversible non-flow process from an initial pressure of 10 bar and temperature 622oC to a temperature of 331 oC whilst generating 85 kJ of work. The specific heat at constant volume in J/kgK for the gas is? 2. Relevant equations 3. The attempt at a solution I really have no idea where to start. I have attended all of my lectures and read all of the notes, but I just do no know where to come at this problem from..?