Question

Two cylinders $A$ and $B$ of equal volume are connected to each other via a stopcock. Cylinder $A$ contains an ideal gas at temperature $T$ and pressure $P$. Cylinder $B$ is completely evacuated. The entire system is thermally insulated. Now stopcock is suddenly opened. Then

• A. The process is an isochoric process
• B. The intermediate states before attaining equilibrium do not satisfy gas equation
• C. Temperature in final state will decrease
• D. Internal energy of the gas increases

Answer 1

The correct option is B The intermediate states before attaining equilibrium do not satisfy gas equation

Since the process (called free expansion) is rapid and cannot be controlled. The intermediate states are non-equilibrium states and do not satisfy the gas equation. In due course, the gas does return to an equilibrium state.