Mixing rules: Difference between revisions

From SklogWiki
Jump to navigation Jump to search
m (Made a stub page)
 
m (Added an internal link)
 
(One intermediate revision by the same user not shown)
Line 1: Line 1:
{{stub-general}}
{{stub-general}}
'''Mixing rules'''
'''Mixing rules''' (see also [[Combining rules]]).
==van der Waals mixing rules==
==van der Waals mixing rules==
The [[van der Waals equation of state]] can be written as
:<math>\left(p + \frac{an^2}{V^2}\right)\left(V-nb\right) = nRT</math>
For mixtures one replaces <math>a</math> and <math>b</math> with expressions that depend on the composition:
:<math>a \rightarrow \sum_i^n \sum_j^n x_i x_j a_{ij}</math>
and
:<math>b \rightarrow \sum_i^n \sum_j^n x_i x_j b_{ij}</math>
where
:<math>a_{ij} = (1-k_{ij}) \sqrt{(a_{ii} a_{jj})} ~~~~~~~~    i\neq j</math>
and
:<math>b_{ij} = \frac{(b_{ii} b_{jj})}{2} ~~~~~~~~    i\neq j</math>
where <math>k_{ij}</math> is obtained from a fit.
See also <ref>[http://dx.doi.org/10.1039/TF9696502034 T. W. Leland, J. S. Rowlinson, G. A. Sather and I. D. Watson  "Statistical thermodynamics of two-fluid models of mixtures", Transactions of the Faraday Society '''65''' pp. 2034-2043 (1969)]</ref>
==References==
==References==
<references/>
<references/>
 
;Related reading
*[http://dx.doi.org/10.1016/0009-2509(86)87103-2 T. Y. Kwak and G. A. Mansoori "Van der waals mixing rules for cubic equations of state. Applications for supercritical fluid extraction modelling", Chemical Engineering Science '''41''' pp. 1303-1309 (1986)]
*[http://dx.doi.org/10.1016/0378-3812(93)85079-2 Kenneth R. Hall, Gustavo A. Iglesias-Silva, and G. Ali Mansoori "Quadratic mixing rules for equations of state: Origins and relationships to the virial expansion", Fluid Phase Equilibria '''91''' pp. 67-76 (1993)]


[[category: classical thermodynamics]]
[[category: classical thermodynamics]]
[[category: mixtures]]
[[category: mixtures]]

Latest revision as of 16:25, 25 February 2014

This article is a 'stub' page, it has no, or next to no, content. It is here at the moment to help form part of the structure of SklogWiki. If you add sufficient material to this article then please remove the {{Stub-general}} template from this page.

Mixing rules (see also Combining rules).

van der Waals mixing rules[edit]

The van der Waals equation of state can be written as

Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \left(p + \frac{an^2}{V^2}\right)\left(V-nb\right) = nRT}

For mixtures one replaces Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle a} and Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle b} with expressions that depend on the composition:

Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle a \rightarrow \sum_i^n \sum_j^n x_i x_j a_{ij}}

and

Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle b \rightarrow \sum_i^n \sum_j^n x_i x_j b_{ij}}

where

Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle a_{ij} = (1-k_{ij}) \sqrt{(a_{ii} a_{jj})} ~~~~~~~~ i\neq j}

and

Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle b_{ij} = \frac{(b_{ii} b_{jj})}{2} ~~~~~~~~ i\neq j}

where Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle k_{ij}} is obtained from a fit.


See also [1]

References[edit]

Related reading