1. The problem statement, all variables and given/known data A piston-cylinder assembly contains air, initially at 2 bar, 300 K, and a volume of 2m3. The air undergoes a process to a state where it pressure is 1 bar, during which the pressure-volume relationship is pv = constant. Assuming idea gas behavior for the air, determine the mass of the air, in kg and the work and heat transfer, each in kJ 2. Relevant equations pv-nrt W = ∫p dv 3. The attempt at a solution I found the constant C to be: pivi = (200,000 Pa)(2m3) C = 400,000 Pam3 vf = C/pf Hence vf = 400,000 Pa m3/100,000 Pa vf = 4m3 W = ∫P dv = ∫24C/v dv W = 277258.9 kJ Mass of air: pv =nrt n = (200,000 Pa)(2m3)/(8.314 J/K mol)(300K) n = 160.372 Pa m3mol/J I'm a little fuzzy on moles and such, but unless I'm much mistaken, I should be able to find the mass of the air by dividing by Avogadro number, right? After this, I can calculate the heat transfer with Q = mcΔT in which I can find the ΔT with the relationship: pivi/Ti = pfvf/Tf Am I making sense?