1. 1 kg of air is polytropically compressed reversibly from 5 bar to 10 bar from an initial temperature of 300°C. Find the transferred heat and the change in entropy. Take the polytropic index as 1.25.
2. 0.5 kg of dry air is expanded reversibly to a final temperature of 100 °C. The work done by the system is 1000kJ. Determine the change in entropy of the system. Take the polytropic index as 1.2.
3. Determine the change in entropy for 1.0 mole of an ideal gas originally confined to one-half of a 5.0-L container when the gas is allowed to expand to fill the entire container at constant temperature.