vapor pressure

pressure caused as a result of the power of vapors spreading

Vapor pressure, also known as vapour pressure, is the pressure of a vapor in equilibrium with its non-vapor phases. All liquids and solids have a tendency to evaporate to a gaseous form, and all gases have a tendency to condense back into their orignal form (either liquid or solid). At any given temperature, for a particular substance, there is a pressure at which the gas of that substance is in dynamic equilibrium with its liquid or solid forms. This is the vapor pressure of that substance at that temperature.
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Vapor pressure Occupational health The pressure exerted by a saturated vapor–the gaseous phase of a liquid, a function of the amount of vapor [more]Vapor pressure - Community and Resources

Noun
1. the pressure exerted by a vapor; often understood to mean saturated vapor pressure (the vapor pressure of a vapor in contact with its liquid form)
(synonym) vapour pressure
(hypernym) pressure, pressure level, force per unit area

A measure of a substance's propensity to evaporate, vapor pressure is the force per unit area exerted by vapor in an equilibrium state with surroundings at a given pressure. It increases exponentially with an increase in temperature. A relative measure of chemical volatility, vapor pressure is used to calculate water partition coefficients and volatilization rate constants.