Berthelot equation of state: Difference between revisions

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The '''Berthelot equation of state''' <ref>[http://dx.doi.org/10.1051/jphystap:018990080026300 D. J. Berthelot "Sur Une Méthode Purement Physique Pour La Détermination des Poids Moléculaires des Gaz et des Poids Atomiques de Leurs Éléments", J. Phys., '''8''' pp. 263-274 (1899)]</ref> can be written as
The '''Berthelot equation of state''' <ref>[http://dx.doi.org/10.1051/jphystap:018990080026300 D. J. Berthelot "Sur Une Méthode Purement Physique Pour La Détermination des Poids Moléculaires des Gaz et des Poids Atomiques de Leurs Éléments", J. Phys., '''8''' pp. 263-274 (1899)]</ref> can be written as


:<math>RT = \left( p + \frac{a}{Tv^2} \right) \left( v - b\right)</math>
:<math>RT = \left( p + \frac{a}{Tv^2} \right) \left( v - b\right)</math>.


where
At the [[critical points | critical point]] one has <math>\left.\frac{\partial p}{\partial v}\right|_{T=T_c}=0 </math>, and <math>\left.\frac{\partial^2 p}{\partial v^2}\right|_{T=T_c}=0 </math>, which leads to (Eqs. 4.1 - 4.3 <ref>[http://dx.doi.org/10.1021/ed039p464 Antony F. Saturno "Daniel Berthelot's equation of state", Journal of Chemical Education '''39''' (9) pp. 464-465 (1962)]</ref><ref>  [http://www.ucm.es/info/molecsim/Berthelot_EOS.sws SAGE Notebook Worksheet] for use in the mathematics program [http://www.sagemath.org/ SAGE]</ref>)


:<math>a= \frac{27}{64}R^2 \frac{T_c^3}{P_c}</math>
:<math>a = 3T_cp_cv_c^2</math>
 
 
:<math>b= \frac{v_c}{3}</math>


and
and


:<math>b=\frac{RT_c}{8P_c}</math>
:<math>R = \frac{8p_cv_c}{3T_c}</math>  
 


where <math>p</math> is the [[pressure]], <math>T</math> is the [[temperature]] and <math>R</math> is the [[molar gas constant]]. <math>T_c</math> is the [[critical points | critical]] temperature and <math>P_c</math> is the pressure at the critical point.
where <math>p</math> is the [[pressure]], <math>T</math> is the [[temperature]] and <math>R</math> is the [[molar gas constant]]. <math>T_c</math> is the [[critical points | critical]] temperature and <math>P_c</math> is the pressure at the critical point.
==References==
==References==
<references/>
<references/>
'''Related reading'''
*[http://dx.doi.org/10.1021/ed039p464 Antony F. Saturno "Daniel Berthelot's equation of state", Journal of Chemical Education '''39''' (9) pp. 464-465 (1962)]
[[category: equations of state]]
[[category: equations of state]]

Revision as of 13:47, 21 September 2010

The Berthelot equation of state [1] can be written as

.

At the critical point one has , and , which leads to (Eqs. 4.1 - 4.3 [2][3])


and


where is the pressure, is the temperature and is the molar gas constant. is the critical temperature and is the pressure at the critical point.

References