Which of the following is $NOT$ a reversible process?

If a Van der Waals gas expands freely,then the final temperature is:

Which thermodynamic process is quasi-static and does not dissipate energy?

$A$ container with rigid walls is covered with perfectly insulating material. The container is divided into two parts by a partition. One part contains a gas while the other is fully evacuated (vacuum). The partition is suddenly removed. The gas rushes to fill the entire volume and comes to equilibrium after a little time. If the gas is not ideal,then

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

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