A liquid placed in a closed container will evaporate until equilibrium is reached.

At equilibrium, which of the statements (A-D) is false?

A) The partial pressure exerted by the vapor molecules is called the vapor pressure of the liquid.

B) Liquid molecules are still evaporating.

C) The number of vapor molecules remains essentially constant.

D) The boundary (meniscus) between liquid and vapor disappears.

E) All of these are true.

(B) Liquid molecules are still evaporating.

Explanation:

Vapor Pressure is exerted by the vapor of the liquid, at equillibrium the partial pressure exerted by vapor molecules is called as vapor pressure by defition of vapor pressure the statement A is true.

Statement B, Liquid molecules are still evaporating this statement may not be true as equillibrium is reached no more liquid state molecules will pass in the vapor phase.

Since its an quillibrium the number of the moleciles in vapor and liquid phase remains constant hence the statement C is also true.

Statement D, The boundary (meniscus) between liquid and vapor disappears this statement is also true as the liquid evaporates the meniscus may fall down.