1.While studying the thermodynamic properties of perfect gases I saw that the change in internal energy for constant volume process is mCvdT. but it is also the same for const pressure, const temp, const entropy and other reversible non-flow processes. Why is it so?? why it is not mCpdT for const pressure process? The value of Cv and Cp are not same. And if we consider the same system working once for const volume and again for constant pressure then will the temp difference be same? I mean will both the process have same initial and final temperature? If the are same then how can be the value of dU be same as the values of Cv and Cp are different? does it work like if i heat CO2 at constant pressure then the value of change in internal energy and if i heat the same amount of CO2 at const volume or const entropy then the value of change in internal energy will be same? I mean has it been experimentally established? 2. dU=mCvdT Why not Cp for const pressure process?