What is vapour pressure? Explain the statement: "In an open vessel,the rate of vaporization is constant,yet equilibrium is not established."

(N/A) Vapour pressure is the pressure exerted by the vapour of a liquid in equilibrium with the liquid at a given temperature in a closed vessel.
Equilibrium is only possible in a closed vessel where the rate of vaporization equals the rate of condensation.
In an open vessel,the vapour molecules escape into the surrounding atmosphere. Consequently,the rate of vaporization $(Liquid \rightarrow Gas)$ is greater than the rate of condensation $(Gas \rightarrow Liquid)$.
Since the vapour is continuously lost to the surroundings,the reverse process cannot occur at the same rate as the forward process,and thus,equilibrium is never established.
Even though the rate of vaporization remains constant at a fixed temperature,the system cannot reach equilibrium because the condensation process is effectively absent or negligible.