Alternative Flame Test Procedures The traditional use of a Nichrome wire during flame tests introduces a limited volume of solution into the flame, making i t more difficult to see the colors for some ions. This is particularly true during demonstrations, when the students may b; seated a t a distance from the flame. There are several better, inexpensive procedures available. Using a strip of folded, wet filter paper t o introduce a paste of the chemical into the flame gives an intense color that lasts until the Daoer becomes drv. This works well for demonstrations but is unsuitable for student use since any excess paste falls onto lab benches and durners. Alternatively, a solution may be dispensed with the aerosol propellants co&nonly used for chromatographic developers. Only a few of them are required for student use since they are easily cleaned by aspirating water into a flame. These propellant sprays are somewhat expensive for student use and some brands dispense the liquid a t such a high velocity that the flame is occasionally blown out, but they are readily available from chemical supply companies. A third alternative is the use of perfume atomizers or the pump-type spray dispensers commonly used with cosmetics. These pumps are easily cleaned by spraying water into a flame, and it is not necessary to use their reservoirs. Several types of these reusable dispensers are available a t variety stores for $1-4 apiece. They are more useful than some cleaning-agent dispensers because the sweep of the cosmetic bottle spray is smaller and contained in the flame, thus eliminating wet lab benches. If the cosmetic bottle reservoirs are used, solutions containing hydrochloric acid should not be stored in them since portions of the pump apparatus frequently are made of metal. ~~~~
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Zexla K. Barnes Morehead State University Morehead, KY 40351
248
Journal of Chemlcal Education
