Porter's approach

(Complete?) Derivation with background, explanation, application cf. LIT and the two linked articles. This means that important information is still missing. Help Wikipedia by researching and pasting it .

The Porter approach , named after Alfred William Porter (1863–1939), is the simplest model for calculating activity coefficients and can be derived exactly from the Gibbs-Duhem equation . It has the advantage that it only requires a single parameter A.

G ^E _{= RTAx1x2}

${\displaystyle \ln(\gamma _{1})=(x_{2})^{2}\cdot A=(1-x_{1})^{2}\cdot A}$

${\displaystyle \ln(\gamma _{2})=(x_{1})^{2}\cdot A=(1-x_{2})^{2}\cdot A}$

However, it has the disadvantage that it represents a symmetrical function and has no meaning in reality because it is too imprecise. After all, this model can even be used for two liquid phases, i.e. H. Segregation, represent.

literature

• Alfred William Porter: The Vapor-Pressures of Mixtures , Trans. Faraday Soc. 16 (1920), p. 336
• Alfred William Porter: Thermodynamics , Methuen (1931)
• Dorothea Lüdecke, Christa Lüdecke: Thermodynamics: Physico-chemical basics of thermal process engineering. Jumper; Berlin, Heidelberg 2000, p. 506. ISBN 9783540668053

Individual evidence

1. ^ Library of Congress: Albert William Porter .