Berthelot equation of state: Difference between revisions

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:<math>b= \frac{v_c}{3}</math>
:<math>b= \frac{v_c}{3}</math>


and
and the critical [[compressibility factor]] is


:<math>\frac{RT_c}{p_cv_c} = \frac{8}{3} \approx 2.667 </math>  
:<math>\frac{p_cv_c}{RT_c} = \frac{3}{8} = 0.375 </math>  





Revision as of 15:09, 22 September 2010

The Berthelot equation of state [1][2] can be written as

.

At the critical point one has , and ,

which leads to (Eqs. 4.1 - 4.3 [3][4])



and the critical compressibility factor is


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

Low pressure variant

Berthelot also proposed an equation of state for use at low pressures:


References