How come when the strength of intermolecular forces decreases, the vapor pressure of something increases?
- ?Lv 51 decade agoFavorite Answer
Vapor pressure depends on the kind of molecules that it is composed of. liquids that evaporate quickly like ethyl alcohol have smaller intermolecular attractive forces, so they show higher vapor pressures than something like ethylene glycol. Ethylene glycol has very low vapor pressure which is a reflection of the strong attractive forces between its molecules. The vapor pressure of the liquid is the pressure exerted by a vapor in equilibrium with its liquid at a given temp.So because a substance has smaller intermolecular attractive forces, more molecules in a shorter period of time will reach the surface creating an increase in pressure, Remember pressure is force per unit area.
- Anonymous1 decade ago
Vapor Pressure = Molecular mass / 2