Question

A liquid placed in a closed container will evaporate until equilibrium is reached. At equilibrium, which of the following statements 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 partial pressure of the vapor is constant.

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

Answer 1

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

B. Liquid molecules are still evaporating. (true, it is a dynamic system and molecules are always moving around. some are also condensing back to liquid.)

C. The number of vapor molecules remains essentially constant. (true as long as temperature and volume are held constant)

D. The partial pressure of the vapor is constant. (true as well as long as temperature and volume are held constant)

E. The boundary (meniscus) between liquid and vapor disappears (false. the assumption is that there is still liquid after equilibrium is reached. The only way this could be accurate is if ALL the liquid evaporated)

Answer 2

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

B. Liquid molecules are still evaporating.(FALSE)

C. The number of vapor molecules remains essentially constant. (TRUE)

D. The partial pressure of the vapor is constant.(TRUE)

E. The boundary (meniscus) between liquid and vapor disappears. (FALSE)

Answer 3

[REMOVED]