How do intermolecular forces affect evaporation?
The stronger the intermolecular interactions the higher the boiling point
Evaporation means the transformation of a substance from its liquid state to its gaseous state and for that you will need to break most of the intermolecular bonds that are holding the molecules together to form the liquid.
Therefore, the stronger these interactions the higher is the energy needed to break them and therefore the higher the boiling point.
Here is a video about Heating & Cooling Curve, where I discuss briefly