$A$ 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 ..... $K$.

$Assertion :$ Thermodynamic processes in nature are irreversible.
$Reason :$ Dissipative effects cannot be eliminated.

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?

There is no change in internal energy of an ideal gas when it undergoes

For the free expansion of a gas,which of the following is true?

Write a short note on reversible and irreversible processes.