How Not to Do It: Chromium Trioxide

Note: this was a post on my old blog site, and never made the migration over to the current "In the Pipeline". I was reminded of it this morning, and thought I'd bring it more out into the light. There are reports (updated here - DBL) that Mars may have hexavalent chromium compounds in its surface dust, which is already being brought up as a concern for future human exploration. I agree with comments I've seen that this is putting the cart in front of the horse a bit, but it also means that I probably wouldn't be a good candidate for the expedition. I've already had my lifetime's exposure to Cr(VI). Back in grad school, I had an undergraduate assistant one summer, a guy who was pretty green. I'll refer to him by an altered form of his nickname, henceforth as Toxic Jim. I shouldn't be too hard on him, I guess: I was a summer undergrad in my time, too, and I wasn't a lot of help to anyone, either. But TJ did manage to furnish me with some of my more vivid lab stories in his brief time in my fume hood. One morning I showed him how to make PCC. That's pyridinium chlorochromate for the non-organic chemists out there, an oxidizing agent that doesn't seem to be used as much as it was 15 or 20 years ago. Even in '85, you could buy it, but the freshly-made stuff was often better. It certainly looked nicer. Like all the Cr(VI) salts, it has a vivid color, in this case a flaming orange. I shouldn't say "flaming;" that's getting ahead of the story. . . It's not hard to make. You t...
Source: In the Pipeline - Category: Chemists Tags: How Not to Do It Source Type: blogs