Vapor Pressure - Estimating Vapor Pressures With Antoine Equation

Estimating Vapor Pressures With Antoine Equation

The Antoine equation is a mathematical expression of the relation between the vapor pressure and the temperature of pure liquid or solid substances. The basic form of the equation is:

and it can be transformed into this temperature-explicit form:

where: is the absolute vapor pressure of a substance

is the temperature of the substance
, and are substance-specific coefficients (i.e., constants or parameters)
is typically either or

A simpler form of the equation with only two coefficients is sometimes used:

which can be transformed to:

Sublimations and vaporizations of the same substance have separate sets of Antoine coefficients, as do components in mixtures. The Antoine equation is accurate to a few percent for most volatile substances (with vapor pressures over 10 Torr).

Read more about this topic:  Vapor Pressure

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