by jasper » 11 July 2014, 08:03
In attached you can see that the water vapor pressure is fine, compared to 5 sources at NIST. As explained, you will not want to affect the phase equilibrium by changing the vapor pressure. The vapor pressure needs to describe properly pure water. And it does.
I also suggested that you turn to a simpler model, where Poynting factor and saturated vapor fugacity are ignored, as this simplifies the fit. This is the DECHEMA model for fugacity caclculations. You did not turn this on.
Furthermore, in attached you can see that reasonable values for A are:
A_water_sucrose 0.572640655
A_sucrose_water 3.190734798
This is not such a difficult exercise and I have the feeling I am doing your homework. You came up with values of
A_water_sucrose 119371138
A_sucrose_water 28035002
And then conclude that it does not work well. Have a look at the parity plot in the attached Excel if you use your suggested values.
While you are at it, also have a look at values of zero for both values of A, this would represent an ideal mixture. Then you see why that option did not work well.
Please properly look at the formulas before asking me to do your homework.
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