Question

Guaifenesin Extraction

Okay, during the extraction of Guaifenesin.

We added 5-mL of ethyl acetate to the crushed Guaifenesin and I knew it was added to solubilize that Guiafenesin

For the next 10 minutes if it was stirred then it was filtered.

The next step confused me. We added 10 mL of hexanes to the filtrate. The question is what was the reason for addition of hexanes to the filtrate?

Thanks

Answer 1

The answer is very simple: the haxne was added to crystallize the Guaifenesin.

I am assuming in your crushed Guaifenesin there was insoluble impurities that need to be separated from pure Guaifenesin.

In order to that you have dissolved Guaifenesin in ethyl acetate. please note that ethyl acetate is a polar solvent which are used to dissolve orhganic compound. then you filter the ethyl acetate soluntion to remove insoluble impurities.

hexane is a non polar solvent, adding it on a ethyl acetate filterate results in overall decrease in polar component of filterate.

let consider initial ethyl acetate has polarity of 100%.

but by adding 10 mL of hexane results in = 5/15*100 = 33%

means polarity of filterate soln decreases to 33%.

This will results in crystallization of pure Guaifenesin.