Final answer:
Stronger intermolecular forces in a liquid result in a lower vapor pressure, whereas weaker intermolecular forces result in a higher vapor pressure.
Step-by-step explanation:
The relationship between intermolecular forces in a liquid and its vapor pressure is such that stronger intermolecular forces lead to a lower vapor pressure, while weaker intermolecular forces lead to a higher vapor pressure.
This is because stronger intermolecular attractions impede molecules from escaping the liquid phase to the vapor phase and facilitate the 'recapture' of gas-phase molecules, thus decreasing the vapor pressure.
In contrast, weaker intermolecular attractions present less of a barrier for molecules to escape into the vapor phase, resulting in a higher vapor pressure.
An example to highlight this relationship is water. Water has strong hydrogen bonding, an intermolecular force, which makes its vapor pressure relatively low compared to substances with weaker intermolecular forces.
This principle applies across different substances, where the vapor pressure at a given temperature will vary depending on the strength of the intermolecular forces present.