Question

If substance X has stronger intermolecular attractions than substance Y, which of the following is most apt to be true?

Choose one of the following options:

	Y has the lower vapor pressure and higher boiling point.
	Y has the higher vapor pressure and higher boiling point.
	Y has the lower vapor pressure and lower boiling point.
	Y has higher vapor pressure and the lower boiling point.

Answer 1

Vapor pressure is the amount of gas in equilibrium with the liquid and solid phases
Intermolecular forces are the attractive interactions between molecules. For something to vaporize, you have to get enough energy together to break these interactions. As a result, you'll need more energy (due to higher temperature) to break apart stronger intermolecular forces
so,
The stronger the intermolecular forces, the stronger the interactions that hold the substance together, the lower the vapor pressure of a liquid at the given
hence, Y has higher vapour presssure

boiling point is directly propional to intermolecular attractions
so,
Y will have lower boiling point

Answer : Y has higher vapor pressure and the lower boiling point.