[Azmosis25]

Hi, i am a junior in high school doing a research paper on the extraction of valerenic acid from the valerian root.

One method in extracting this acid is using  EtOH/H₂O with a ration of 70% 30% respectively.

my question is, are there any ways of calculating the polarity of a dilute solvent- so in this case the polarity of this mixture of 70%Etoh and 30%H₂O

[voidSetup]

I"m not sure exactly on this, but I think one gets an idea of a solvent's polarity based on its dielectric constant.

[Azmosis25]

so if thats the case, is there any formula used to work out the dielectric constant?

[voidSetup]

Dielectric constants have to be measured experimentally.  It's just one way to get an idea of a solvent's polarity, there are more precise ways than that.  I'm not sure how it works though if it is a mixture, and not the pure solvent.