I'm a third year chemical engineering major and this is my first real thermodynamics class, so I'm not entirely sure what I'm doing. Any help is greatly appreciated! 1. The problem statement, all variables and given/known data A rigid horizontal cylinder contains a freely moving piston. Initially, it divides the cylinder into equal volumes, and each side of the piston contains 1 mole of an ideal gas at 5°C and 1 bar. An electrical resistance heater is installed on side A (left side) of the piston, and is energized to slowly heat the gas on side A to 170°C. If the tank and the piston are perfect insulators, calculate the heat added to the system by the resistance heater. The molar heat capacities of the gas are: Cv = (3/2) R and Cp = (5/2)R. (Hint: choose your system wisely.) 2. Relevant equations [tex]PV=nRT[/tex] [tex]\Delta U = W + Q[/tex] [tex]\Delta U = nC_v\Delta T[/tex] [tex]P = P_i (v_i/v_f)^\lambda[/tex] 3. The attempt at a solution First I started off by converting the known data into the proper units and calculated the initial volume of each side using the ideal gas law. [tex]T_Ai = T_Bi = 278 K[/tex] [tex]P_Ai = P_Bi = 1*10^5 N/m^2[/tex] [tex]n_Ai = n_Bi = 1 mol[/tex] [tex]T_Af = 443K[/tex] [tex]V_Ai = V_Bi = 0.023 m^3[/tex] Now onto choosing a system. I'm torn on whether to choose A or B. Side B is adiabatic so I could use this equation [tex]P = P_i (v_i/v_f)^\lambda[/tex], but I don't know have a way to find the final volume of B. Side A is not adiabatic so I'm left with [tex]\Delta U = W + Q[/tex] and [tex]\Delta U = nC_v\Delta T[/tex], but like side B I don't have a way to find the final volume to calculate the work being done. A push in the right direction would be awesome. The assigned textbook for this class has proven to be very unhelpful.