- #1
Gianmarco
- 42
- 3
Homework Statement
A cylindrical container with rigid walls is divided in two sections by a barrier with negligible mass that is free to move without friction along the axis of the cylinder. The barrier is adiabatic and so is half of the cylinder while the other half let's heat through. The cylinder contains ##n = 2\:mol## of perfect monatomic gas distributed in the two sections. Initially the container is in contact with the environment at ##T_0=300\:K## and the barrier is at equilibrium in the center. The cylinder is then put in contact with a reservoir at ##T_f = 280\:K## and the barrier is at equilibrium in a place such that the ratio of the volumes of the two sections is ##R = \frac{10}{9}##. Calculate the initial temperatures in the two sections of the cylinder
Homework Equations
PV = nRT
The Attempt at a Solution
So we are not given the amount of moles in each section, but we know that since we are at equilibrium in both initial and final states, then ##P_{1i} = P_{2i}## and ##P_{1f} = P_{2f}##. So, since at the beginning the volumes are the same because the barrier is in the middle: ##P_{1i}V_{1i} =P_{2i}V_{2i} \rightarrow n_1T_{1i}=n_2T_{2i}\\ T_{1i}=\frac{n_2}{n_1}T_{2i}##
The final state is what confuses me. I wasn't able to find out the respective values of ##n_1,\:n_2## so I looked through the solutions and it says that ##T_{1f} = T_{2f}=280\:K## when the system reaches equilibrium in contact with the reservoir. How is this possible? Shouldn't only the non-adiabatic section be at T = 280 K?