dogsoldier wrote:Interesting! Why can't we use acetone for the initial pulls from the lye soup then?
Acetone is miscible with water. This is due to its polar group, which creates hydrogen bonds with water.
The lye soup is an aqueous system. If you add acetone to it, it will mix with the water, which will make it impossible to pull anything. To pull anything you need two separate layers (e.g. two liquids, or a liquid and solids).
You can only pull with acetone from dry material, which is what you do in the second pull stage, after the sodium carbonate basing. If your acetone is not anhydrous (i.e. free from water), it will pick up some of the sodium carbonate, as well as sodium acetate (resulting from the neutralization reaction of the sodium carbonate with the acetic acid) and whatever other water-soluble things might be in there.
P.S. I'm not a chemist and I'm only learning and trying to understand this, so those more knowledgeable please feel free to correct me.