Answer to Question #55942 in General Chemistry for Lia

Question

What effect does (a) decreasing the pressure or (b) increasing the pressure above a liquid have on the liquid’s boiling point?

Answer 1

At boiling point the pressure of vapors of the liquid equals the pressure above the liquid. Also, the
pressure is directly proportional to temperature as shown by Gay-Lussac’s law: p = CT, where C –the
constant.
a) Hence, if the external pressure decreases the liquid boils at the lower temperature. Boiling point
decreases;
b) On contrary, increasing the pressure increases the boiling point.