Friday, February 2, 2018

Homeschool Science: Process-Oriented Experimentation with Exothermic Reactions

The kids and I are using CK-12's 9th/10th grade Biology textbook as the spine for this year's biology curriculum--for Will, who is in the eighth grade but who is taking high school-level coursework, this will be recorded as Honors Biology on her transcript.

Chapter 2 of CK-12's biology textbook is entitled "The Chemistry of Life," and includes a section on biochemical reactions, including exothermic and endothermic reactions.

Exothermic reactions, in particular, are simple to create with household supplies, so this was a great chance for the kids to practice their scientific observation.

To begin, I set up a series of solids and liquids on our big table, with the proper measuring tool for each one, as well as a card that noted if one needed to wear gloves, goggles, and breathing mask before using it. I ended up with distilled water, vinegar, acetone, hydrochloric acid, baking soda, lye, potassium iodide, epsom salts, steel wool, yeast, and hydrogen peroxide. 

I also provided two large thermometers and supplies to clean them between uses.

The kids were required to write down the procedure in their science notebooks--

--and then were free to begin the experiments that were as much process-oriented play as scientific inquiry:

Hydrogen peroxide, lye, and hydrochloric acid all called for the use of the gloves, goggles, and breathing mask:

The straps of the breathing mask ALWAYS get caught in our hair...

I can't even tell you what combinations the kids tried, as I was more focused on standing guard and keeping them from pouring hydrochloric acid in their eyes or licking the lye. This reaction, though, is surely lye and water or lye and vinegar:

The kids loved the experience, and the more so, I think, because the loose format allowed for the element of play--of creating new possibilities and trying them out as they wished, with little worry about structure or product. Science needs more playfulness than we usually allow kids to have; so much of science is follow this specific method, record these results this particular way, do exactly this thing in order to see exactly the thing that you're supposed to see, etc.

That's important, sure, but you know what? Playing is important, too!

P.S. Want to create even more exothermic reactions? Check out what you can do with potassium nitrate and sugar, and hydrogen peroxide and potassium iodide.

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