Question

We have equal amounts of two identical ideal gases at the same temperature T but at different

pressures p1 and p2 in two containers. Containers are connected. Find the change in entropy.

Answer 1

Solution;

Since the gases are ideal;

$\Delta s=C_vln(\frac{T_2}{T_1})+Rln(\frac{v_2}{v_1})$

But $T_2=T_1$

Therefore;

$\Delta s=Rln(\frac{v_2}{v_1})$

The gases are ideal;

Pv=RT;

$v=\frac{RT}{P}$

$\Delta s=Rln(\frac{\frac{RT_1}{P_1}}{\frac{RT_2}{P_2}})=Rln(\frac{P_2}{P_1})$