1. The problem statement, all variables and given/known data Containers A and B hold the same gas. The volume of B is four times the volume of A. The two containers are connected by a thin tube (negligible volume) and a valve that is closed. The gas in A is at 300 K and pressure 1.0 * 10^ Pa. The gas in B is at 400 K and 5.0 * 10^5 Pa. Heaters will maintain the temperatures of A and B even after the valve is opened. After the valve is opened, gas will flow one way or the other until A and B have equal pressure. What is this final pressure? 2. Relevant equations 3. The attempt at a solution The part with the two different temperatures confuses me. Here's what I tried: Maybe this can be considered a constant temperature process P1V1=P2V2 Va = Volume of A Vb = 4Va (1.0 * 10^5 Pa)(Va) = (P2)(5Va) P2= 20000 Pa ---- I am quite sure this is not correct because if I choose the other gas, I get a different answer. Also, I think the number of moles is changing because the gas flows between the compartments. Could somebody give me a hint as to how to work in all of these factors into an equation? Thanks.