Cation and Anion Testing for Unknown Chemicals Project 2, Section 506 Introduction It has been found that some pet food can be tainted with melamine, and cause serious illness in cats and dogs. The presence of melamine gives a false indicator of protein when tested. Since the compound melamine contains large amounts of nitrogen, we can test the pet food for nitrogen through cation and anion testing. Materials and Methods Part 1 The chemicals needed for this part of the experiment were K+, Fe3+, Zn2+, Cu2+, Co2+, 6 M NaOH, and 15 M NH4OH. These solutions should be in dropper bottles. Also concentrated HCl was be needed. The equipment need for this part of the experiment are 10 centrifuge tubes, a test tube rack, a distilled water bottle, medicine dropper, cobalt glass, Nichrome wire loop, striker, a 50 mL beaker, a stir rod, pipets, and a Bunsen burner. To begin the experiment, 5 centrifuge tubes were labeled for each of the 5 cations, K+, Fe3+, Zn2+, Cu2+ and Co2+. 10 drops of each solution was added to the appropriate centrifuge tube. 6 M NaOH was added drop wise to each solution until a precipitate was formed, or until 20 drops were added. Another 10 drops of 6 M NaOH were added to the solutions that formed a precipitate. Again, 5 centrifuge tubes were labeled for the same 5 cations and 10 drops of each solution were added to the appropriate centrifuge tube. The 15 M NH4OH was added drop wise until a color change occurred, or until 20 drops were added. An additional 10 drops of 15 M NH4OH were then added to each solution. Again, 5 centrifuge tubes were labeled for the same 5 cations and 20 drops of each solution were added to the appropriate centrifuge. HCl was also added to a 50 mL beaker. The Nichrome wire loop was dipped in the HCl solution and placed over the Bunsen burner to disinfect it. The wire loop was then dipped in the K+ solution and placed