Vapor Pressure

• It is the pressure exerted by the vapor when a liquid or solid is in equilibrium with its vapour phase.
• It’s a measure of a substance’s tendency to evaporate.

Factors Affecting:

• Temperature:

  • Higher temperature increases vapour pressure because more particles have enough energy to escape into the vapour phase.

• Nature of the Liquid:

  • Substances with weaker intermolecular forces have higher vapour pressure.

Dynamic Equilibrium:

• In a closed container, when the rate of evaporation equals the rate of condensation, the vapour pressure stabilizes.
• Example: A closed bottle of water eventually reaches a state where the water vapour in the air above the liquid exerts a constant pressure.

Importance of Vapor Pressure:

1. Weather and Climate: Influences humidity and the formation of clouds.
2. Industrial Applications: Important in processes like distillation and refrigeration.
3. Safety: High vapour pressure substances can be more flammable or pose evaporation-related hazards.

Example of Vapor Pressure:

• At 25°C, water has a vapour pressure of about 23.8 mmHg. If placed in a sealed container, water vapour will exert this pressure when equilibrium is reached.

Thank you for reading from Firsthope's notes, don't forget to check YouTube videos!