A liquid is placed in a closed container. Equilibrium is reached when
A) all of the liquid evaporates
B) when the rate of condensation equals the rate of evaporation
C) when the rate of condensation exceeds the rate of evaporation
D) when molecules cease to pass from the liquid state to the vapor state

Question

Quizplus · Accepted Answer

Equilibrium is reached when the rate of condensation equals the rate of evaporation, meaning there is a constant exchange of particles between the liquid and vapor phases, but the overall amount of each does not change. Option A is not possible as it would imply that the container is not truly closed or that the liquid has a very high vapor pressure. Option C is not correct as it would mean that the liquid is decreasing in volume, which is not characteristic of equilibrium. Option D is incorrect as molecules are still passing between phases, just at equal rates.

A Liquid Is Placed in a Closed Container