Two cylinders $A$ and $B$ of equal capacity are connected to each other via a stop cock. Cylinder $A$ contains an ideal gas at standard temperature and pressure. Cylinder $B$ is completely evacuated. The entire system is thermally insulated. The stop cock is suddenly opened. The process is:

Two cylinders $A$ and $B$ of equal capacity are connected to each other via a stopcock. $A$ contains a gas at standard temperature and pressure. $B$ is completely evacuated. The entire system is thermally insulated. The stopcock is suddenly opened. Answer the following :
$(a)$ What is the final pressure of the gas in $A$ and $B$?
$(b)$ What is the change in internal energy of the gas?
$(c)$ What is the change in the temperature of the gas?
$(d)$ Do the intermediate states of the system (before settling to the final equilibrium state) lie on its $P-V-T$ surface?

$A$ container of volume $1 \ m^3$ is divided into two equal compartments by a partition. One of these compartments contains an ideal gas at $300 \ K$. The other compartment is vacuum. The whole system is thermally isolated from its surroundings. The partition is removed and the gas expands to occupy the whole volume of the container. Its temperature now would be ..... $K$.

$A$ process can be reversible if

In case of free expansion, which one of the following statements is $\underline{\text{WRONG}}$?

What is an irreversible process and what is a reversible process?