Problem 1 b. Determine dU for an ideal gas using the expression in part a. Does dU depend on temperature or pressure or both? av c. Let O= and KI= Using the van der Waals equation of state aT ap RT a P = V-b /2, derive expressions for a and Kr. For a van der Waals gas, does du depend on temperature or pressure or both? au d. Derive an expression for av) in terms of P, T, a, and KT. T e. For a van der Waals gas, derive the expression for enthalpy change associated with an isothermal expansion from Vi to 12. How does this compare with the enthalpy change of an ideal gas undergoing isothermal expansion from Vi to V2