1. The problem statement, all variables and given/known data An Ideal Gas at 300K has a volume of 15L and a pressure of 15 atm. Calculate the change when the system goes under a reversible adiabatic expansion to a pressure of 10 atm. Gamma = 5/3. Cv = 1.5R. q = 0(definition of adiabatic processes). 2. Relevant equations dw = P DV (lowercase means squiggly d and uppercase means straight d) P = nRT/V 3. The attempt at a solution The answer in the book says w = 5130 J, which is the opposite of what I got for the internal energy. First, I calculated n: n = PV/RT = 15 atm * 15 L / .08206 (L*atm / K * mole) * 300K n = 9.14 moles Then, I calculated Vf: Vf = [(Pf * Vi ^ (5/3)) / (Pf)] ^ 3/5 Vf = 19.13 L dW = P DV dw = NRT (dw = P DV so then work = NRT * Integral [DV/V]) ****This is wrong since T changes temperature between states***** w = nRT ln(Vf/Vi) Plugged in everything and the answer didn't turn out.