LETTERS . ..
Hydrated Cations To the Editor:
Old Spectroscopists Never Die To the Editor:
On reading the article, "Hydrated Cations in the General Chemistry Course", by George B. Kauffman and John F. Baxter, Jr., I was struck by the familiarity of the material. Almost all of it occurred in the aualitative analvsis course. now largely discontinued: Use of hydrated ion formulas &hen writing correct equations for the reactions, insoluble hydroxides, amphiprotism, tendency of some salts to hydrolyze in solution, coordination numbers for complex ions, etc. Some general chemistry labs contain a few experiments on the cation scheme. If laboratory time for the complete course can no longer be provided, I suggest that the study of the scheme in the classroom could provide most of the material described by Kauifman and ~ a x w rplus , some useful inorganic chemistry. It could also he presented as an important part of the history of chemistry-a pn)cedurr that was taught, largely unchanged, t i x over one hundred years, which certainly is significant. I learned this by reading the first edition (1841) of "Guide to Qualitative Chemical Analysis, or System&: Methods for the Identification of Substances Freauentlv Occurring in Pharmacy, the Arts and Industry" by ~ a ; l Remegius Fresenius (title translated from the German). His original procedure is described in a half-semester text I have written for qualitative analysis. The experiments consist of the identification of indicators in mixtures by paper chromatography and color ranee and the identification of minerals by cation flame tests usinga filter, anion spot tests, and water determination, since some minerals differ only by water of hydration.
Part of the second vear (sophomore) course in our departmen1 includes a series of lectures on spectroscopy. It is in this context that a competition was held in order to test the feeling of our student body about just what might happen to old spectroscopists. Below is quoted the report of the adjudicator (AAD) in the hope that t h e results may be of interest to chemical educators and may stimulate further research into the fate of old practitioners of various chemical disciplines. Although many and varied suggestions were made as to where old spectroscopists go, on reading the entries there is very little doubt as to where the mind of most young spectroscopists goes. The large number of blatant Freudian allusions to "excite," "emission," "excitation" coupled with such choice terms as "stimulated" and "degenerate" leaves little douht as to what turns on our spectroscopy students. Faced with a wealth of inventiveness and many very good entries it was necessary to set criteria for judging the best entry. These are that
Frederick C. Strong Ill ProfessorTlldlar IFEAA) Un~ver%daaeEs1aa.d de Camp nas I3100 Campmas. SP. Bras11
To the Editor: We are both in agreement with the points raised by Professor Strong in his letter. We made no claim that any of the material used inour approach was new. but rather we impliell-or intended to imply -..that we advocated an at least partial return to the pre-Sputnik practice of including mure descriptive chemistry in the chemistry course. We merely chose the topic of hydrated cations as one example to illustrate how this might he accomplished with a unified approach using concepts that are usually dealt with in the introductorv course. ~ l t h o u g hmuch of the material that we presented.in our article can be found in eeneral chemistw texts. it is often scattered in several places. As ~rofesso;%rodg correctly points out, much of it was formerlv dealt with in the lareelv discontinued qualitative analysis course. Although one of us (GBK) considers himself an historian of chemistry, neither of us was aware that Fresenius made use of hydrated cation notation in his classic "Anleitung zur qualitatiuen chemischen Analyse" (Bonn, 1841). We are grateful to Professor Strong for drawing our attention to this interesting but little known fact. George B. Kauffman California State University. Fresno Fresna, CA 93740
John F. Baxter, Jr. Distinguished Service Professor of Chemistry, Emeritus Universily of Florida Gainesville, FL 32601
438
Journal of Chemical Education
1. Correct and appropriate use of spectroscopic terms should he
made;
2. Whether by euphemism, allusion, or simile the alternative fate of
the aging spectroscopists should be something fairly terminal; and :I. 'The play t l f wmds in thr wmning rntry should have that undefinable quality w h w h make< it inctantlv rrwynizat,lr as n wlnnrr by all. This last criterion. to mv mind. excluded some of the "double-barrel" entries althokh some were very good indeed. I quote one which qualifies as a place-getter because of the fir& part
.. .but their excitation frequency decays to six nanofeet below the ground state. Had the entrant put a full stop after ". . decay" it may well have been the winnine- entrv. The runner up is an entry which gets alphas fur criterion one and three but is weak in identifsinr - - the fate of ~rldsoectroscopists
. . . they just lose their resolution. Many people lose their resolution, not only old spectroscopists. Indeed I have come across mans irresolute young.sDectros. copists. The winning entry has an alpha minus for the first criterion but is excellent in all other respects they just reach a ground state. As the adjudicator's decision is final and unchal~en~eable there is no need to justify the excellence of the entry. I should, however. explain the aloha minus. The weakness lies in the use of the i;definite article "a." They just reach the ground state or their eround state would he more correct. T o sav "a" implies more than one ground state, i.e., a degenerate grhund state, and, for those who are familiar with the Jahn-Teller theorem, this is impossible unless the molecule is linear. I t is because the entrant assumed that old s~ectroscopistsare linear without stating it that the alpha minus was &en. A. A. Dlamantls
f. Kurucsev Department of Physical and Inorganic Chemistry The University of Adelaide, Adelaide, S.A.. 5001. Australia
