Richard Rodakovilz East Leyden High School 3400 Rose Street Franklin Pork, Illinois 60131
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To any teacher the symptoms are obvious: uninquisitive countenance, laconic incurious responses, and overall remissness in writing assignments. Bright sunshine and warm weather seem to aggravate the condition. The diagnosis is all too familiar also to any C.P. (Chemistry Practitioner): Second Semester Poisoning (SSP). When left untreated, Second Semester Poisoning can be contagious. The "disease" can spread to English, Mathematics, and Social Studies. An acute case may even be fatal to a promising young scholar's gradepoint average, leading to disappointment, a feeling of inferiority and total fmstration. all of which are lethal to a student's academic intea. rity-an essential element of a healthy educational diet. With the fond memories of early studenthood still fresh in our minds we sympathized with those afflicted with SSP and sought a cure for this dreaded ailment. A consensus showed that the symptoms of SSP were prevalent several days before and after a vacation, particularly amund Christmas time, and that laboratory experiments such as "Partial Thermal Degradation of Mixed Saccharides with Protein Inclusions"' (Peanut Brittle Synthesis) had transitory healing effects. Thus, a conference was called of all the prominent C.P.'s a t our school and a general ~rovhvlaxiswas ~rescrihed. ~e k p e r a t i n g measure consists of a demonstration. This demonstration, though, is not an ordinary one. Since warm sunny days are frequent in late May or early June, a time when SSP is a t a peak, the display is done outside, preferably in the bleachers of a football stadium. The "show" consists of a series of controlled combustion experiments which never fail t o light up the patient's eyes (if done carelessly the bleachers may also be lit up). While some may view this with disfavor, associating it with a fmworks display, a great deal of chemistry may he learned if conducted properly. One C.P. sits with the patients in the stands and speaks through a microphone, lecturing about the various reactions they will see shortly. Another C.P. administers the curative. With several fire extinguishers handy, a pair of asbestos gloves, safety shield erected, and safety glasses distributed, the show is ready to begin. A thundering bang pierces the air sending a cardboard ton. from a 5-lh can of calcium carbonate, 50 ft u ~ w a r d . 'I% show ; has hegun. What they just saw (and hea&) was the combustion of acetylene produced from calcium carbide and water. The crowd has stopped talking and is waiting attentively for the next dosage of medicine. As the C.P. explains
426 / Journal of Chemical Education
The SSP Syndrome the various flame tests used in qualitative inorganic analysis, piles of gunpowder are burned containing barium, ereen.. red.. and strontium. and calcium salts omducine.,.. yellow flamer, respectively. Accelerating oxidation is next. First iron in the form of filines is burned in the flame of a propane torch followed by t c e rather violent reaction hetween smoldering steel wool (also iron) in an oxygen-rich atmosphere produced from manganese dioxide and hydrogen peroxide. The C.P. now tells the patients that oxygen can be added to a fuel through an oxidizing agent. This is illustrated by adding-a little bit of concentrated sulfuric acid to a mixture of potassium chlorate and s ~ c r o s e . ~ Piles of magnesium metal and potassium nitrate are burned3 following warnings not to look directly at the burning magnesium. Various other "interesting" mixtures are burned. Already the morale of the patients has picked up. For safety's sake the proper use of a fire extinguisher is shown a t this point. For the budding organic chemists cotton is burned, immediately followed by cotton nitrated with HN03/H&04, guncotton. The treatment is ended with the spectacular displays of t h e ~ m i t eCrOa , ~ and acetone, and whistles.5 The applause from the patients indicates the regimen was successful. The prognosis is encouraging. To verify this, they are given handouts containing reactions just obSewed, which must be balanced, and definitions, which must be completed for homework. The homework is completed the next day and the students listen attentively to the lectures once again. The therapy worked. So, for those of you with ailing students, if you don't mind putting in a few extra hours, a little smoke and noise, and a warm sunny day outside the classroom, this little rejuvenating experiment should be tried. The industrial artists learn to respect acetylene, the fuel used in their oxyacetylene torches. The chemistry students gain knowledge of unusual reactions, the hazards of certain compositions, and safety procedures if confronted with a fire. Bear in mind, however, that safety is foremost when conducting this display. 'Adams, Richard C., J. CHEM. EDUC., 49,536 (1972). 2ALyea, H. N., and Dutton, F. B., "Tested Demonstrations in Chemistry."6thEd.. 1969, p. 17. 3Weingart, George, W., "Fyrotechnies," 2nd Ed., Chemical Publishing Co., New York, 1941, p. 137. 'Alyea, H. N., and Dutton, F. B., "Tested Demonstrations in Chemistry,"6thEd., 1969, p. 17. $Weingad, George W., "Fymtechnics," 2nd Ed., Chemical Publishing Co., New York, 1947, p. 180.
