Chemical Education Today
Letters An Alternative Thermochemical Container I was intrigued with the JCE Classroom Activity: #59 “Some Like It Hot, Some Like It Cold” (1). I think that a polystyrene foam egg carton (or even multiple nested cartons) would be an adequate container for mixing the solutions and performing thermochemical measurements. These cartons are readily available and would not require potentially dangerous preparation methods such as knives and heat guns, as suggested in the Activity. Most of the cups in the typical egg
carton shown in the picture have a capacity of 15 mL (the end cups have a capacity of 10 mL). The quantities of reagent used in the Activity could simply be scaled up by factors of five to ten. A polystyrene foam form used to ship test tubes (such as the one shown in Figure 1) has wells with capacities of 2–3 mL. This would likely be an acceptable holder for mixing thermochemical reagents as well. Literature Cited 1. Silberman, R. G. J. Chem. Educ. 2004, 81, 64A–64B. Dean J. Campbell Department of Chemistry and Biochemistry Bradley University Peoria, IL 61625
[email protected] The author replies: Dean Campbell suggests a clever, readily available, and simple alternative to the calorimeters described in my article. I tried his suggestion and egg cartons work well with the appropriate scale up of materials. The only advantage I see to the calorimeter I described is somewhat greater durability and need for smaller amounts of chemicals. Robert G. Silberman
Figure 1. A typical polystyrene foam egg carton and a polystyrene foam form for shipping test tubes.
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[email protected] Vol. 81 No. 10 October 2004
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Journal of Chemical Education
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