A Bancroft point is the temperature where an

azeotrope An azeotrope () or a constant heating point mixture is a mixture of two or more liquids whose proportions cannot be altered or changed by simple distillation.Moore, Walter J. ''Physical Chemistry'', 3rd e Prentice-Hall 1962, pp. 140–142 This ...

occurs in a

binary system A binary system is a system of two astronomical bodies which are close enough that their gravitational attraction causes them to orbit each other around a barycenter ''(also see animated examples)''. More restrictive definitions require that th ...

. Although vapor liquid azeotropy is impossible for binary systems which are rigorously described by Raoult's law, for real systems, azeotropy is inevitable at temperatures where the saturation

vapor pressure Vapor pressure (or vapour pressure in English-speaking countries other than the US; see spelling differences) or equilibrium vapor pressure is defined as the pressure exerted by a vapor in thermodynamic equilibrium with its condensed phases ...

of the components are equal. Such a temperature is called a Bancroft point. However, not all azeotropic binary systems exhibit such a point. Also, a Bancroft point must lie in the valid temperature ranges of the

Antoine equation The Antoine equation is a class of semi-empirical correlations describing the relation between vapor pressure and temperature for pure substances. The Antoine equation is derived from the Clausius–Clapeyron relation. The equation was presente ...

. Bancroft point is named after

Wilder Dwight Bancroft Wilder Dwight Bancroft (October 1, 1867 – February 7, 1953) was an American physical chemist. Biography Born in Middletown, Rhode Island, he was the grandson of historian and statesman George Bancroft and great-grandson of Aaron Bancroft. ...

External links

Separation of Azeotropic Mixtures
Phase transitions Thermodynamics Distillation Temperature {{thermodynamics-stub

See also

External links