solution: (i) w = -2150 J, q = 4150 J, ΔU = 2000 J; (ii) w = -1573 J, q = 3573 J, ΔU = 2000 J. As U is a state function, irreversible expansion in case (i) would give the same ΔU for the same initial and final states. A gas phase reaction takes place in a bomb calorimeter. Assuming the total number of moles is conserved and perfect gas behavior, show that ΔH = (Ccalorimeter + nR) ΔT.