Here's why:

* Entropy is a measure of disorder or randomness in a system.

* Liquids have a more ordered structure than gases. The molecules are closer together and have less freedom of movement.

* Gases have a much more disordered structure. The molecules are far apart and move around freely.

When a liquid changes to a gas (evaporation or boiling), the molecules gain more freedom of movement and spread out, leading to a significant increase in entropy.