Chemistry: Lessons in Thin Air

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     Chemistry was always my favorite science growing up. It allowed me to do unsavory things with forbidden materials in a frightful manner, with often embarrassing results—all in the serious pursuit of discovery through experiment. I hope to make it your favorite science, too, by conveying some amazing facts.

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     The most amazing is this: the chemical reaction that Mother Nature plays with every day is every bit as frightening as what I did in my devious experiments. And she does it in thin air!

It’s called oxidation. It’s the most common reaction in nature, and it happens all around us. (It happens inside us as well, but that’s a later biology lesson.)

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     As you may have cleverly concluded, oxidation requires oxygen. A lot of it. But so do we—and every other animal. So, oxygen needs to be made all the time. And this brings us to the second most common reaction in nature: photosynthesis.

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     This is also done in thin air. Plants snatch carbon dioxide out of the air, along with water vapor, and use sunlight as a wand to create their own food: sugar. This is magic, of course, but the point is that a product of this reaction is oxygen! Plants don’t need it, so they expel it. You might think of oxygen as a botanical waste product. The magical formula, for anyone curious, is 6CO2 + 6H2O → C6H12O6 + 6O2↑.

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     So, with plenty of oxygen available, Mother Nature can play with oxidation. This can be fast or slow. When it happens slowly, things like rust and old age are the result. When it happens rapidly, we get combustion and hot-tempered youth.

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     The explosive oxidation of hydrogen produces water, the most abundant compound on Earth. This reaction is reversible: an electric current can separate water into hydrogen and oxygen. This is how fuel cells in future automobiles are made. The magic formula for this is 2H2 + O2 ↔ 2H2O.

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     Finally, if you enjoy wine you need to be aware that the oxidation of alcohol produces vinegar (C2H5OH + O2 → CH3COOH + H2O), which is why you should finish that whole bottle before sundown.

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Ron Wetherington