chemistry laboratory report Experiment 9

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PROCEDURE FOR FLAME TEST

Nichrome Wire Clean-up Use the following procedure to clean the Nichrome wire before performing the flame test. Adjust the Bunsen flame to pure blue. Heat the wire to incandescence in the edge of the

flame. At first you will observe a coloration of the flame; this is due to the presence of the metal ions on the surface of the wire. The coioration should disappear in a few seconds. If it does not, remove the wire from the flame, let it cool for about 5 seconds, and then dip the wire into a few milliliters of concentrated hydrochloric acid in a test tube Reheat the wire and repeat these steps until no color emanates from the wire.

Flame Tests 1. Obtain seven (7) clean test tubes. 2. To each test tube add 1 mL of 0.1 M of solutions of NaCl, KCl, CaClz, SrClz, BaClz,

CuClz andZnClz. 3. Test each solution by dipping the cleaned Nichrome wire in the solution and then

transferring it to the flame. 4. Record the flame color in your notebook. 5. Clean the wire thoroughly by following the wire clean-up procedures each time you

change test solutions.

WASTE DISPOSAL Solutions of NaCl, KCl, and CaClzz Flush down the sink with rururing water. Solutions of SrClz, BaClz, CuClz and, ZnClz: Put in a waste bottle labeled Heavy Metals - Solutions. Conc. HCI solution: Add phenolphthalein and neutralize with 1 M NaOH (first appearance of pink color). Flush down the sink with running water.

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