Chemistry Question: - RonO's Ramblings — LiveJournal
|Mar. 9th, 2009 08:21 pm Chemistry Question:10 comments - Leave a comment |
Heat, my boy.
When I used to make rock candy, I would boil me some water, and stir in sugar while it boiled, till it wouldn't take no more. Quickly pour boiling solution into jar, place lid with string hanging down into jar - DO NOT TIGHTEN LID.
Let cool - when room temp is reached you may already see crystals forming on string. you can then screw on the lid and let nature take it's course.
Why the hell are they having kids use Acetone when both salt and sugar are dissolvable in water? The vinegar i can understand but acetone is an extremely dangerous solvent.
Actually, the experiment was to see if by using a solvent with a higher evaporation point you could grow larger crystals. The problem being that salt and sugar do not dissolve well in acetone. So these solutions were affected by the saturation levels, not just solvent evaporation rates. There are salt crystals formed on the string above the vinegar level though.
I guess my point was - they could have done the evaporation test using something safer, like methyl alcohol.
Ahhh, but it was I who decided to use acetone - not the school - it was cheap and it was there. And, I'm sure kiddo would have wrinkled his nose just as hard at the smell of methanol and he did with the acetone.