tic effect by comparison to solutions that do not exhibit the phenomenon.
tion below the cmc, which is 0.20 mM for a 1:l CTAB:KHP micelle. The effect of temperature on viscoelasticity has also been observed by other authors andis still under investigation (7). The temperature dependence of the rheological phenomenon can he illustrated by putting a CTAB:KHP sample lahove the cmc) in an ice hath and another in a 50 OC temperature hath; after allowing the samples time to equilibrate thermallv. remove them from the hath and demonstrate that th; elastic recoil has disappeared for the high temoerature sample. The rheological phenomenon, viscoelasiicity, discussed here, is of interest to chemical engineers and chemists in applications from tertiary oil recovery to detergent formulatibns. In summary, recent developments in the field of surface/ colloid chemistrv ~ ~ ~ can ~ he ~ utilized to stimulate the undermaduate to perceive the "due of learning physical c h e s s t r y beyond the mediocre goal of passing this course. The development of micellar catalysis can easily he related to new technoloeical hreakthrouahs " - ( 8 ) .The advancement of medical research can he directed tied to chemical separations utilizing electrophoresis techniques. A basis of these techniques involve the understanding of the free energies of complex formation. One of the simplest aggregate structures to he studied is the micelle. The thermodynamic theory for micellization is not trivial, hut the students can he exposed to the thermodynamics for the prescribed phenomena and he encouraged to learn the statistical mechanics. This system can he understood in a aualitative manner as prolate micelles, hut there are still numerous research questions on viscoelasticitv. The underaraduate can he inspired knuu,ing that their skiils can he utilized to solve future research problems.
univer&y of Florida Galnesvllle, FL 32611
Acknowledgment The author wishes to thank John 0. Edwards and Charles Marzacco for the positive encouragement and helpful suggestions throughout this research. The financial support of Rhode Island Collegeand the numerous hours of work by the undergraduate researcher, Robin Turhitt, involved in this research have allowed this project to he more successful than originally envisioned. The author gratefully acknowledges the suggestions of the reviewers that highlight the viscoelas-
We have oerfected a method for 6emonstrating metal flame tests in the classroom. An ordinary plant-leaf sprayer is filled with a 1 M solution of a metal salt. The atomizer is adjusted to make a fine mist. The solution is then sprayed into the flame of a large Fisher hurner. A darkened room enhances the demonstration. The flame color intensity is further enhanced by adding up to 10-40% methanol to the aqueous solution. A 1- X 1-m square of plastic placed under the burner prior to the demonstration allows for quick cleanup.
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Literature Clied 1. ~ y s e lK. , J. Infrnd~rtionto Colloid Chemiairy: Interscience: N e w York, 1959; pp 253273. 2. (a) Olwm, U.: Sodermen, 0 . ; Guering, P. J. Phys. Chsm 1986. 90, 5223-5232. ihl Wennerrtrorn, H.; Ulmius. J.; Johansron, L. B - A ; Lindblom, G.: Gravrholr. S. J. P h y s Chem. 197%83,2232-2236. 8. (a) lyer, R. M.; Rso. U. R. K.: Manahar. C.: Valauliksr. B. S. J. P h y s Chem. L987.91, a28&3291. (hl Gravsholt. S. J . Coil. & Istwfai. Sci. 1976.57.576-577. 4. Gravsholt.S. InPolymerColloids. Fiteh,R.. Ed.. Plenum: NewYork. 1979; Vol. 11, p i ] . 5 . is1 Rujimethabhe~.M.: Wilsirat, P. J. Chem Educ 1978.55, 342. !hi C o r k M. L.: Harkinr, W. D. J. Am. Chpm Sac. 1917.69.679-688. icl Flockhait. 5 . D. J. Call. & Inlsrfor.Sci. 1957.12,557-560. (dl Harkins. W. D.; Jordan. H. F. J.Am.Chem.Sor. l930,52.1751-1772. 6. (a1 5achofer.S. J.;Turhift,R. J. Coil &Interfoe. Sci. 1990,135, 325-334. ibl Jan~son. J. M.;Stilhs.P. J.Phys.Chem, 1987.91.Ll2-116.(c)Sesmehorn.J.F.;Rathmsn.J.F, Phys. ('hem. 1984. R8.5807-5816. 7. Hoffman". H ; Rehage. H.: Reidea". K.; Th",", H. I" Mac,". & Mzeroemulaions: Theory and Applicotionr. Shah.D. 0..Ed.: 1972; ACS Sympo~iumsoriesVol. 272, pp
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8. (a1 Cordes. E. H.. Ed. Reactions Kinetics in M~rdles;Plenum: N e w York. 1973. !hl Menger, F. M.: Portnoy,C. E. J.Am. Chsm. Soc. 1967,89,4698--1703. ic) Fendler. J. H.: Fendler, E, d. Cololysis in Micellar and Mocromoleculor Soluliuns; Academic: N e w York. 1975.
Spectacular Classroom Demonstration of the Flame Test for Metal Ions Suwlmo sr
Bruce M. Mattson, Roberl L. Snipp, and Gary D. Mlchels Creighton Unlverslly
Omaha, NE 68178 CHECKED BY
Kathrvn R. Wllllams
Eleventh Annual Fall Computer-Using Educators Conference The Eleventh Annual Fall Computer-UsingEducators Conference will be held October 18-20,1990 at the Santa Clara Convention Center and adjoining Doubletree Hotel, Santa Clara, CA. In keeping with the Conference theme, Global Technology: Connections for Educators, hundreds of open sessions will address bilingual education, distance learning, Enalish as a second lsnguage, foreign language, international studies, networks, and telecomputing. In addition, professional development wili be stressed in sessions on topics such as: administration, assessment, computer coordination, curriculum integration, subject-specific content and methodology, and teacher productivity tools. There will also be is required, field trips, and over 220 exhibit booths with the latest several hands-on worksho~sfor which Drereaistratian . educational hardware and software. Registration materials have already been sent to members of Computer Using Educators, Inc., the Conference sponsor. Others may join and receive more information about the Conference by writing or calling: CUE, 4655 Old Ironsides Drive, Suite 200, Santa Clara, CA 95054 (phone: (408)727-5165, FAX: (408) 432-9892.
Volume 67
Number 9
September 1990
791
