system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How does salt increase the boiling point of water, I know it does but how?
gpt
In any liquid the molecules are in motion. Even if the liquid is motionless, if you could look at the molecules with a powerful microscope you would see them moving around and bumping into each other.

The motion is due to thermal energy. Some molecules move faster than others. Some have enough energy to escape from the surface of the liquid and become vapor. Even if the liquid is not boiling, some vapor escapes from its surface.

When the temperature is raised high enough the pressure of the escaping vapor equals the pressure of the air over the liquid. Bubbles form inside the liquid because the vapor pressure is high enough to push the liquid out of the way.

If you add something to the liquid that dilutes it, the vapor pressure is decreased. That is because there are fewer liquid molecules per square inch on the surface because some of them have been replaced by the dilutant. Fewer molecules on the surface means fewer molecules escaping and less vapor pressure.

The dilutant can be anything that dissolves. The phenomenon does not depend on the molecular properties of the dilutant, it only has to dissolve.

Edit: this is a well known phenomenon in chemistry. Search "boiling point elevation".