chemistry – Page 27

“Reactions with solid formation,
We classify precipitation:
Mix solutions (aq),
And the (s) formed anew
Will crash out to observer’s elation.”

The next few limericks address specific classes of chemical reactions and how to identify and interpret them: again, a common theme of many General Chemistry courses. The first, from 5 April 2019, is a reaction type that figures heavily in both introductory chem courses and my interdisciplinary course, Chemistry in Art.

“Reactions with solid formation,/ We classify precipitation:”
Much like balancing reactions, another intro-level skill is identifying types of reactions; chemical reactions often have tell-tale reactants or products that allow their classification. Reactions in different classes follow set patterns, so once we’ve done our classification, we can explore more interesting aspects of the pertinent chemistry.

For instance, a precipitation reaction involves the formation of a solid product called a precipitate; this product “falls” out of solution (parallelling the everyday definition of precipitation).

“Mix solutions (aq),/ And the (s) formed anew/
Will crash out to observer’s elation.”
To identify a precipitation reaction, we look for a process with two identifying characteristics. First, the reactants are aqueous solutions (compounds dissolved in water); they are designated as such by the (aq) abbreviation after their chemical formulas. Second, one product is a solid, which is designated by the (s) abbreviation after its chemical formula. The final line of the poem notes that precipitation reactions are fun to watch, as the solid product “crashes out” of the solution.

Here’s a sample reaction, in which aqueous solutions of potassium chloride (KCl) and silver nitrate (AgNO₃) yield a precipitate of silver chloride (AgCl) and a side product of aqueous potassium nitrate (KNO₃); we can see the pattern described in lines 3-5 of this limerick:
KCl (aq) + AgNO₃ (aq) → AgCl (s) + KNO₃ (aq)

Precipitation reactions have implications for the interdisciplinary overlap of chemistry and art. Silver chloride itself is light-sensitive and participates in reactions associated with black-and-white photography. Some solid precipitates formed in other precipitation reactions are brightly colored and can be used as pigments in mixing and using paints.

This virtual space: still uncharted;
My first few attempts have been thwarted.
But thoughts keep repeating:
The time here is fleeting;
Get moving; get writing; get started.

I’ve always thought of myself as both a chemist and a writer, but little evidence exists of the latter role, compared to the former. I’m hoping to change that in terms of my creative routine this year.

The last few years have brought some tentative steps in that direction. Most concretely, I greatly enjoyed a poetic experiment in April 2019, wherein I celebrated the overlap of the International Year of the Periodic Table and National Poetry Month, “five lines at a time,” with a set of thirty limericks over thirty days, shared on my Twitter account. I’ve been meaning for several months to go back and provide some additional context and content, so that the limericks could conceivably be useful/educational, as well as format-appropriate. That intent is my most specific and immediate aim, here. I plan to keep each of these initial entries constrained to 280 words, given their origin in Twitter’s 280-character limit: hoping to keep the discussion distinct and direct.

More generally, the “what I wish I’d known” list gets a bit longer every year, as it applies to both 2000 (as a chemistry student in college) and 2010 (as a new chemistry professor). I’ve thought for a while about attempting to compile and communicate some of that information, and this could be a space for that purpose.

And finally, at the risk of this entry’s becoming a bit of a Mobius strip, I’ve found the rediscovery of creative writing to be restorative during the past few years: writing about writing will be a third common topic here, I imagine. While the techniques or resources I’ve discovered are not remotely new, they have all at some recent point been new to me. I’d thus like to create my record of what has helped, in the hopes that it might conceivably someday help others.

As with so many things, it is daunting to try, but more daunting to consider not-trying! So: to be continued.