Especially JCE: February 2017

“The common image of chemistry is in fact a rather wretched one, full of hazards, risks, and pollution. The word ‘chemicals’ has become synonymous with ‘dangerous substances’ in the popular culture. ‘Unfair,’ we chemists cry, ‘and so uninformed.’ But what is being done to improve the public’s perception of chemistry?”

Does the above Journal of Chemical Education (JCE) excerpt match your view of the general public’s perception of chemistry in 2017? If so, you may be interested to learn that these comments appeared over twenty years ago, on the pages of the September 1996 issue. Its author, Richard N. Zare, then the newly appointed Chair of the governing body of the National Science Foundation, linked his question with the results of a survey of science museums. The survey showed a distinct lack of chemistry in science museums—a missed opportunity to impact this negative perception.

Zare recognized that the pages of JCE are a good place to mine for ideas about exhibits and encouraged readers to share their successful experiences of working with science museums. Articles specifically related to this topic have cropped up here and there in the intervening twenty years, and the February 2017 issue of JCE offers another that could serve the high school teacher as well as science museum exhibit planners: Bringing Organic Chemistry to the Public: Structure and Scent in a Science Museum (available to JCE subscribers).

The authors describe an exhibit with several purposes: “to make organic molecules relatable to the general public,” “to make chemicals less intimidating,” and to communicate that “scents are chemicals, and molecular structure determines biological activity.” Visitors smell various “Scent Bottles” with a goal of identifying the scent. Each bottle has an associated molecular model that shows a related scent compound. The exhibit also provides molecular model kit pieces and handouts for hands-on building of scent molecules. Part of the exhibit shows pairs of molecules that are related to each other structurally. I was amused at one handout’s instruction to “Turn vomit into pineapple!” I can easily picture it appealing to some students, but also appreciate that it shows just how close the two structures are to one another. The molecular model materials and instructions can be reused from year to year.

Figure 4 – Reprinted with permission from Bringing Organic Chemistry to the Public: Structure and Scent in a Science Museum M. Kevin Brown, Laura C. Brown, Karen Jepson-Innes, Michael Lindeau, and Jeremy Stone. Journal of Chemical Education, 94 (2), 251-255. Copyright 2017 American Chemical Society.

For those who wish to create the Scent Bottles, I asked the corresponding authors for advice on locating and purchasing the various scents. Many of the chemicals they used were on hand in their department’s stockroom, or they ordered them from chemical companies. Other options were suggested:

Grocery store (these are items where the scent is basically the pure compound): microwave popcorn (diacetyl), almond extract (benzaldehyde), vanilla extract (vanillin), cinnamon extract (cinnamaldehyde), vinegar (acetic acid), menthol (menthol, not included in the paper), and spearmint extract (R-carvone; S-carvone is the characteristic smell of caraway - I see that extract is also available).

Internet: Butyric acid (vomit) is apparently available (quick google search), but the others might be more difficult to obtain. Pineapple and banana extracts are available, but I’m not sure what the exact compositions are. Amyl acetate (also banana) is available, and my guess is that they’d be able to find most of the fruit esters as well.

Other classrooms: Geosmin is expensive to buy, but if there is a biology teacher nearby who knows how to grow streptomyces bacteria, the characteristic smell that will emanate from the plates is geosmin. (L. C. Brown, personal communication, February 13, 2017)

How might chemical educators use the ideas from the article?

  • Turn the exhibit into a hands-on classroom activity for your students.

One possibility for adapting the “Scent Bottles” would be to use Jelly Belly brand jelly bean flavors (including the more disgusting ones offered with Bertie Bott’s Every Flavour Beans, such as dirt and vomit) for guessing, since the sense of smell plays a major role in how we perceive flavor. Or, the exhibit’s molecule building activities could be used as a first, directed attempt at general molecular model building, or as an introduction to organic molecules.

  • Use the exhibit as a hands-on activity for community outreach, such as at a science night event, a school open house, or during outreach to elementary schools.
  • Collaborate with a local science or children’s museum to offer such an exhibit, either as described or on a smaller scale.

More from the February 2017 Issue

Don’t miss Mary Saecker’s JCE 94.02 February 2017 Issue Highlights for further content from this month’s issue of the Journal. Lots of article titles sparked my interest this month.

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