Question #18679

1 Answer
Jul 21, 2016

It is a different solvent; it is not necessarily a better one.


Ethanol is an excellent solvent for organic compounds as it contains both polar and non-polar functionalities. Organic solutes TEND to have some solubility in hot ethanol, but poor solubility in the cold solvent. This of course is the preferred scenario for the experimental chemist.

Ethanol also has a good temperature range; i.e. you can put it in the freezer, after heating it to boiling. And on this point, since ethanol is none too flammable you could use a heat gun to get the solvent hot. You cannot do this when you use hexanes as a solvent because of concerns of flammability; (and if you do you do not let your supervisor catch you doing so!).

Ethanol is also miscible with hexanes, so this non-polar solvent can be used to layer an ethanolic solution. You can't do this with methanol or water. Why not?

The other signal advantage that ethanol enjoys over water is that you do not have to dry your crystals so much. As an added bonus, ethanol smells nice and is gentle on the hands. Of course, you always have to use the solvent that works.