1 mole of an ideal gas initially at 100° C and 1 atm is expanded adiabatically against a constant pressure of 5 atm until equilibrium is re-established. Given that the temperature dependence of the heat capacity is CV = 4.50 + 0.005T calculate ?U, ?H and ?S for the change in the gas.
Not sure how to approach this question. Also I am not the most confident with entropy calculations