Concepts Of Physics MCQ Edition [Volume 2]PhysicsKinetic Theory of Gases
A closed bottle contains some liquid. The quantity of this liquid is continuously decreasing. The vapour present in the remaining space
Options
- Amay be saturated
- Bmust be unsaturated
- Cmust be saturated
- Dwill be completely absent
Correct answer
B. must be unsaturated
Step-by-step solution
In a closed bottle, if the vapour is saturated, a dynamic equilibrium exists between the liquid and its vapour, meaning the rate of evaporation equals the rate of condensation. In this state, the quantity of the liquid remains constant. Since the quantity of the liquid is continuously decreasing, the rate of evaporation must be greater than the rate of condensation. This net evaporation is only possible if the vapour pressure in the empty space is less than the saturated vapour pressure. Thus, the vapour present in