2. A gas contained in a cylinder is isothermally compressed from 2 bar to 10 bar at 523 K. If the gas obeys the virial equation of state with B= -451.8 cm/mol, Determine the following: a) Find an expression of the change of internal energy in terms of measurable variables starting from U=U(T,P). b) Use the virial equation of state to determine the change of internal energy that occurs in the process