Boiling occurs when molecules have enough kinetic energy to separate
from each other.
Two forces hold molecules and atoms in a condensed state
Pulling forces from the intermolecular attractions.
Pushing forces from the pressure applied on all surfaces of the liquid
(from both the container and the gas above the liquid)
Below is an interactive graph that displays what happens when you alter
the temperature, pressure, and type of substance with varying intermolecular
forces. The red line depicts the amount of energy needed by a molecule to
break free from the liquid state. See if you can demonstrate two distinctly
different circumstances in which you have created the conditions for boiling.
Sketch these graphs and describe the boiling environment.
The boiling point occurs when enough molecules have enough
energy to break free from their intermolecular forces (van der Waals bonds)
and the external pressure keeping them together. This can be achieved in several
ways.
You can heat the substance so that enough molecules break free.
You can lower the pressure on a substance to make it easier for the
molecules to break free with the energy they already posses.