R. W. R a m e t t e
Carleton coleae Northfield, MN 55057
II
Exocharrnic Reactions
When young Humphry Davy passed an electric current through potassium hydroxide and "saw the minute globules of pot&sium burst through t h e crust of potash and iake fire a s they entered t h e atmosphere, he could nut contain his joy-he actually hounded about t h e room in ecstatic delight; and some little time was required for him t o compose himself sufficientlv t o continue the exoeriment. An entrv in Davv's notebook ~"oncludeswith the statement, Capital ex>erimenintl" ( I 1. And further. "the little metallic globules alwavs a o ~ e a r e d a t t h e cathode, and these had a n astonishing w a i o f hirsting into flame when thrown into water. They skimmed about excitedly with a hissing sound and soon burned with a lovely lavender light" (2). Clearlv these chemical changes evolved not onlv several forms ofenergy, b u t also a great quantity of charm [M.E., charmer a trait t h a t fascinates, allures or delights. A combination of entirely attractive and delightful traits. Compelling attractiveness and appeal dispelling.any .~ . o s s i b l ereserved or antagonistic feeling:](3). T h e joy of chemical experimentation has been well recognized a t least from the early days of alchemy, and our appreciation of chemical charm probably dates hack t o t h e prehistoric discovery of ways t o make and control fire. Therefore i t seems useful to coin the term exocharmic reaction [Gk., exo-, turning out] and, particularly in our role as chemistryteacbers, t o seek and share techniques for liberating as much charm as possible from the chemical changes our students see in the lab and through classroom demonstrations. The Laws of Charmodynamics T h e controlled uses of chemical charm may involve as much artistry as formal science. However i t seems reasonahle to set down a t least four main assumptions: 1) Any chemical change, particularly one which is both thermo-
dynamically and kinetically spontaneous, is inherently exocharmic and may he considered to possess an indefinite amount of latent charm. 2) When thereaction mcurs the fraction of the latent charm evolved depends directly upon the technical and histrionic skills of the person oerformine the exoeriment. 3) The fraction of the evolved charm which is resorbed (the free charm) is d~rectlydependent upon the intellectual and psychological preparation of the person viewing the experiment. 4) Charm is not conserved in the transfer pmcess. Even though the amount liberated is restricted hy the second law, corh viewer absorbs acc. I:iO. IH) 1 l r i g y r . T S..and Hnuscher. W. C., .I. CHEM. EI)UC..SO.496 1197:31. 191 Hildebrand. d. H.. "Science in Lhe Mnkiny," C d a m l ~ i aUnirerrity Prers, psperlmek
Volume 57, Number 1, January
1980 1 69
