1) Explain what is meant by the terms "isothermal expansion" and "adiabatic expansion". In each case derive an expression for the work done in expanding an ideal gas. Derive an expression for the change in temperature which occurs during adiabatic expansion.

2) Calculate the work done on a closed system containing 50 g of argon gas when it expands reversibly from a volume of 5 L to a volume of 10 L at a constant temperature of 298.15 K. Relative atomic mass of argon = 39.948

3) 5 L of argon gas at 100 kPa and 298.15 K expands reversibly and adiabatically to twice its initial volume. Calculate the final pressure, the work done and the change in temperature, given that Cp/CV = 1.67 for argon.