# Thermodynamics, system of 2 gases

1. Mar 26, 2012

### fluidistic

1. The problem statement, all variables and given/known data
Two particular systems separated by a diathermic wall have the following equations of state:
$\frac{1}{T^{(1)}}=\frac{3}{2}R \frac{N^{(1)}}{U^{(1)}}$
$\frac{1}{T^{(2)}}=\frac{5}{2}R \frac{N^{(1)}}{U^{(2)}}$ where R=1.986 cal/mol K, $N^{(1)}=2$ and $N^{(1)}=3$.

2. Relevant equations
Euler relation in entropy representation: $S=\sum _j F_j X_j$. In energy representation: $U=TS+\sum _j P_j X_j$.
Gibbs-Duhem relation under the entropy and energy form respectively: $\sum _j X_j dF_j=0$, $SdT+\sum _j X_j dP_j =0$.

3. The attempt at a solution
I simply don't know what formula to use and how exactly. Here they don't give the pressure so this seems really hard to use any formula. I don't know if I can use the ideal gas relations $PV=nRT$ and $U=KT+U_0$, they don't say anything about the gases.
I realize that V is constant.
Any help on getting me started will be appreciated!