Question

If a substance "X" boils at 145' Celsius, then 'X' was heated up to 750' Celsius, after which it was cooled to 500' Celsius at what temperature we can get the 'X' back in its liquid state?

1) 250' C
2)200' C
3)100' C
4)145'C​

Answer 1

Answer:

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.