Vapor Pressure of Liquid Solution 1

[rkinga2]

If I have a solution of one liquid, say gasoline, of known vapor pressure,
dissolved in another liquid of known vapor pressure, say diesel fuel
- what's the vapor pressure of the solution?

 

[25362]

This is a very general "undetermined" question. The VP of the mixture would apparently be somewhere in between both original VP values. The true value depends on the amount and chemical type of the light and heavy components of both gasoline and diesel.

 

[rkinga2]

Thanks.

Would Raoult's law give a pretty good guess?

VPtot = X1*VP1 + X2*VP2

Where X's are molar %

 

[25362]

The chemical composition (aromatics, paraffins, etc.) of both fluids would bear effect. The "absorbing" power of the different -and polar- chemical species may affect results.

One shouldn't forget the huge amount of work that has been done to predict the VP of a gasoline (reformulated or not) depending on the blending VP values of the components (oxygenates and others) i/o to regulate the permissible amount of butanes.

The applicability of Raoult's law for large dilutions should better be checked by actual lab testing. Don't you think so ?

 

[rkinga2]

Thanks for the comments.

Obviously, testing would be best.