Consider a rigid, insulated box containing 0.400 mol of He(g) at 30.0°C and 1.00 atm in one compartment and 0.600 mol of N2(g) at 100.0°C and 2.00 atm in the other compartment. These compartments are connected by a partition that transmits heat. What is the final temperature in the box at thermal equilibrium? [For He(g), Cv = 12.5 J K-1 mol-1; for N2(g), Cv = 20.7 J K-1 mol-1.]