Which of the following processes is reversible?

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

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

$A$ closed container is fully insulated from the outside. One half of it is filled with an ideal gas $X$ separated by a plate $P$ from the other half $Y$,which contains a vacuum as shown in the figure. When $P$ is removed,$X$ expands into $Y$. Which of the following statements is correct?

$Assertion :$ Reversible systems are difficult to find in the real world.
$Reason :$ Most processes are dissipative in nature.

$A$ thermally insulated container is divided into two parts by a screen. In one part,an ideal gas is filled at pressure $P$ and temperature $T$. The second part is a vacuum. If a small hole is now created in the screen,the temperature of the gas will: