A sample of hydrogen gas, which may be assumed to be ideal, is initially at 3.0 bar pressure and a temperature of 25.0 °C, and has a volume of 1.5 dm3. It is expanded reversibly and adiabatically until the volume is 5.0 dm3. The heat capacity Cp of H2 is 28.80 J K-1 mol-1 and may be assumed to be independent of temperature. Calculate: a. the final pressure and temperature (0.552 bar; 182.9 K) b. ∆U and ∆H for the process.