A liquid placed in a closed container will evaporate until equilibrium is reached. At equilibrium, which of the following statements is not true?
A) Liquid molecules are still evaporating.
B) The number of vapor molecules remains essentially constant.
C) The partial pressure exerted by the vapor molecules is called the vapor pressure of the liquid.
D) The boundary (meniscus) between the liquid and the vapor disappears.
E) All of these statements are true.

Question

Quizplus · Accepted Answer

At equilibrium, the amount of liquid molecules and vapor molecules remains constant and the vapor pressure exerted by the vapor molecules equals the atmospheric pressure. However, the boundary (meniscus) between the liquid and vapor phases still exists, it just doesn't move anymore as the rates of evaporation and condensation are equal at equilibrium. Therefore, statement D is not true.

A Liquid Placed in a Closed Container Will Evaporate Until