We’re four weeks into chemistry, and at least the labs are a hit. Oh, I’m sure they secretly enjoy scientific notation, significant figures, heat capacity equations, and dimensional analysis, but they hide their passion for those nuts and bolts well. Who’s fooling who? They’re in it for the labs.
As I’ve posted on my website for the course (and every course with two non-related students needs its own website), we’re using the Illustrated Guide to Home Chemistry Experiments: All Lab No Lecture as our lab guide. Robert Bruce Thompson’s comprehensive labs serve basic to AP chemistry learners, and, with legally obtainable chemicals and equipment, are quite doable at home. It’s also utterly real chemistry. No baking soda and red cabbage indicators here. Nope. This is the real deal, including they boys’ favorite lab to date: distillation. The assignment was to purify ethanol (70% solution) using distillation, taking advantage of the lower boiling point of the ethanol. They were successful (new solution was about 80%), after a bit of a false start that involved a bit of mess but no fire or explosions. But they weren’t satisfied.
They wanted to distill something else, and, given we’d acquired the equipment and knew they had some kinks to work out, I agreed. Hydrogen peroxide is feasible but not terribly safe. Water is certainly safe but rather boring. After much discussion and even more dissent, they agreed to distill the alcohol from some red wine that was aging not-so-gracefully in my fridge. Yeah, I let the boys make brandy (directions here). My older son regaled me and the other child’s mother with questions about the legality of the venture. We assured him that if we didn’t drink or sell it, we were fine. Somewhat comforted, he and his partner in this parent-sanctified federal offence began the process.
Distillation is boring. Well, boring unless you heat your original liquid too much, causing it to run into your condenser tubing (They did. Twice.). So, to make it more interesting, one should make it more technical. And my son’s buddy did just that. On the ethanol distillation, they filled the condenser with cold water, periodically draining it as the distillate warmed it and refilling it with a syringe. It was messy, slow, and totally not high-tech enough. So on the second run, they employed a windshield wiper pump hooked up to a 12V battery to do the periodic water exchange for them. It worked beautifully, saving much labor that could have, I felt, gone into attending to the ever-rising temperature of the original liquid, avoiding the aforementioned overheating. But I’m not 13.
And the brandy? Absolutely vile. A drop to the tongue was enough to make us decide that moonshine-making wasn’t a career option. And no worries about legalities: the distillate is all slated for using in an alcohol burner. The distillation itch is scratched for now, but I’m sure that down the line, the boys would be open to other (legal and safe, preferably) labs utilizing that distillation equipment and handy pump. Or perhaps they’d rather practice some more dimensional analysis. Dream on, Mom!