Question

Two liquids $A$ and $B$ boils at ${145}^{o}C$ and ${190}^{o}C$. Which of them has higher vapour pressure at ${80}^{o}C$?

Answer 1

Vapour pressure correlates with boiling point inversely. In this case liquid A has a lower boiling point and thus will have higher vapour pressure. Since liquid A has a lower boiling point you can assume that its inter-molecular forces are weaker. Therefore, it is much more likely to become a vapour at lower temperatures and more vapour means more pressure.