At a given temperature, the vapor pressure of liquid A is greater than the vapor pressure of liquid B. All of the following are true about liquid A except?

Liquid A has a higher boiling point
Liquid A has a lower boiling point
liquid A has weaker intermolecular forces than liquid B.
The freezing point of liquid A is lower than that of liquid B.

Question

At a given temperature, the vapor pressure of liquid A is greater than the vapor pressure of liquid B. All of the following are true about liquid A except?

Liquid A has a higher boiling point 
Liquid A has a lower boiling point 
liquid A has weaker intermolecular forces than liquid B.
The freezing point of liquid A is lower than that of liquid B.

matt101 · Answer

The first two answers are exact opposites, so one must be wrong. That means the second two answers must be right and we don't to worry about them.

A liquid boils when its vapor pressure matches atmospheric (or ambient) pressure. As you increase the temperature of a liquid, its vapor pressure increases, since the additional energy allows more particles to escape from the liquid phase. If Liquid A has a higher vapor pressure than Liquid B at a given temperature, it will boil sooner for this reason. That means Liquid A has the lower boiling point, and option A above is wrong.

photon336 · Answer

@matt101 Does that also have to do with intermolecular forces as well? b/c a liquid with weaker IMF would mean more molecules would escape into the gaseous phase sooner meaning higher vapor pressure. I guess that's how i thought of it. wouldn't weaker IMF imply higher vapor pressure?

photon336 · Answer

ah wait.. sorry

photon336 · Answer

it said all of the following EXCEPT so that means that i'm looking for the answer that's wrong.

photon336 · Answer

Thank you