Vapor pressure is the pressure exerted by the gaseous form of a substance in equilibrium with its liquid or solid form at a given temperature. It is a measure of the tendency of a substance to escape from its liquid or solid state and enter the gas phase.
Vapor pressure can be determined experimentally by measuring the pressure of the gas above a liquid or solid at different temperatures. It can also be calculated using thermodynamic equations and physical properties of the substance.
The vapor pressure of a substance is affected by temperature, intermolecular forces, and molecular weight. Generally, higher temperatures, weaker intermolecular forces, and lower molecular weight result in higher vapor pressure.
Vapor pressure plays a crucial role in several industrial processes such as distillation, evaporation, and drying. It also helps in understanding the behavior of substances in different states, and is used to determine the purity of a substance.
Vapor pressure is directly related to the boiling point of a substance. At the boiling point, the vapor pressure of the liquid is equal to the atmospheric pressure, causing the liquid to boil and enter the gas phase. As the atmospheric pressure increases, the boiling point also increases.