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SPRAY FLAME SPECTROSCOPY STEM Collegian Center Project Presented by Njimikara Abianui and Leke Abondem Atabong 7 December 2007 Supervised by Prof. William A. Boyle THE FLAME TEST EXPERIMENT It is one of the earliest analytical techniques in chemistry. It identifies elements by the colors they produce in flames. There are many ways of performing this test; each of which has its pros and cons. Wooden splint, cotton swab, loop, spray bottle methods. This project considered two of these methods: the loop and the spray bottle methods. LOOP METHOD Involves the use of a wire inoculation loop (platinum wire is desirable), a Bunsen burner and solutions of salts containing the elements. The wire inoculation loop is cleaned between tests by keeping it in the flame until all the color due to the element is gone. Inadequate cleaning of the loop can make color identification difficult. SPRAY BOTTLE METHOD Introduces a mist of the element solutions directly into the flame. Time saving. No problems of color contamination from previous tests. MATERIALS 5% solutions of Li2CO3, NaCl, CuSO4, KCl Sr(NO3)2 60 mL spray bottles. Bunsen burner COMPARISON LOOP METHOD SPRAY BOTTLE METHOD High cost of platinum Affordable spray bottles. wires. Easy to clean and maintain. Difficult to eliminate element contamination Uses comparable amounts from nichrome-steel wire of solutions as the loop (a less expensive method. substitute for platinum). No flame color Flame color contamination. contamination. Time consuming. Faster to use. RESULTS LITHIUM SODIUM POTASSIUM COPPER STRONTIUM CONCLUSION The loop method was time-consuming and prone to errors in the colors produced. The spray bottle method is faster and produces the clean colors of each element. ACKNOWLEDGEMENTS The plastic spray bottles used in this experiment were kindly provided to PGCC courtesy of B.F. Ascher & Co., Inc., Lenexa, KS, USA. http://www.bfascher.com/ REFERENCES Dogancay, Deborah. "Flame Tests Performed Safely: A Safe and Effective Alternative to the Traditional Flame Test." The Science Teacher 72.6 (2005): 34-38. Science Resource Center. Thomso Gale. Prince George's Community College Library. 6 Dec. 2007 <http://galenet.galegroup.com>. Johnson, Kristin, and Rodney Schreiner. "A Dramatic Flame Test Demonstration." Journal of Chemical Education 78.5 (2001): 640-41. 6 Dec. 2007 <http://www.eric.ed.gov>.
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