Smackdown.

Saving non-scientists at work, one e-mail at a time. It's comforting to know that I still have scientific smackdown potential despite my change of major.

The section-heading graphics in Lesson 8 display a beaker of water and a shaker of salt and are captioned “Neutralized Acid and Base,” as if the term “acid” refers to the water and “base” refers to the salt. I’m confused; water can act as both an acid and a base depending on its chemical environment, and table salt (NaCl) is neither an acid nor a base (incidentally, the chloride ion, dissociated, is considered one of the weakest and most negligible bases in chemistry thanks to the strength of its conjugate acid). I don’t get why the picture says “neutralized,” as this isn’t a buffer situation (which is what the lesson is about), except in the very least chemical sense—perhaps the artist is referring to the negligible reaction between the dissociated chloride ions and free hydrogen ions in water, but that’s pretty chemically sophisticated, and unless the artist is a pedantic chemist I don’t think that’s what he/she intends. I would definitely hesitate to label a picture of salt and water “Neutralized Acid and Base” unless you’re presenting a pretty detailed argument. I mean, the lesson itself is about titration, for heaven’s sake; avoid the controversy and just use H2SO4 and NaOH or something.

In Lesson 10, the section-heading banners read “Fe + O2 = picture of rusted car.” Though logical to a non-scientist, this is chemically untrue. FeO2 can’t even form; to satisfy the electronic requirements of the compound Fe would have to appear in a +4 oxidation state (which doesn’t happen). FeO can form (iron (II) oxide), but this is a very rare black powder, not rust. Fe2O4 can form (iron (II,III) oxide), but this is not rust either; it is the mineral magnetite. The artist is probably trying to depict Fe2O3 (iron (III) oxide, or traditional rust).

On a less this-is-wrong-science and a more this-is-good-scientific-practice note, the section-heading graphics for Lesson 3 feature the equation “R=0.0821=62.4=8.31.” This is untrue. 0.0821 does not equal 62.4 or 8.31, though those are all legitimate values of R. Those numbers are absolutely meaningless and totally unequal without correct units attached. This concept (which version of R to use, and where) confuses enough students as it is, and I think a graphic like that gives students the incorrect impression that those numbers are interchangeable and you just use whichever one you want.

Jessica Sagers