Cations And Anions Lab

Introduction: There is a very big importance in knowing a compounds identification. Throughout history, there have been errors in the identification of compounds in items such as pet foods leading to deadly effects. Part one and two of the project will require students to use chemical tests to identify cations and anions. In an ionic compound, there are cations and anions. Through the identifications of cation and anions, students will discover the unknown ionic compound that is given to them.

Materials and Methods: In part one of the experiment, materials were gathered: 10 centrifuge tubes, test tube rack, distilled water bottle, disposable pipets, cobalt glass, nichrome wire loop, striker, 50mL beaker, Bunsen burner and striker, ring stand,

Each solution was put in separate labeled test tubes. Original observations were recorded. 6M NaOH was added until a precipitate was formed (20 drops were not exceeded). Observations were then recorded into the lab manual. To the solutions that created a precipitate and addition of ten drops of NaOH was added. Observations were then recorded. Solutions were disposed into the proper waste container, and distilled water was used to rinse the contents into the waste container. HCl was used to clean the centrifuge tubes. In the labeled centrifuge tubes, ten drops of each metal cation solution were put in. 15 M NH4OH solution was added into each tube until a precipitate or color complex was created. Observations were then recorded. An additional 10 drops of NH4OH were added to the solution. Observations were recorded in the lab manual. Solutions and contents were properly disposed. In each centrifuge tube, twenty drops of metal solutions. The ring stand clamped the Bunsen burner in place, and the Bunsen burner was connected to desktop gas jet. Then, the Bunsen burner was lighted.

Elimination tests were performed at the same time for each of the four anions (chloride, carbonate, sulfate, and nitrate). Ten drops of the metal anion solution were added to centrifuge tubes. Original observations were recorded into the lab manual. 0.1 M AgNO3 was added to solution until precipitate was formed (no more than four drops were added). Observations were recorded into the lab manual. To the centrifuge tubes that formed a precipitate, 6 M HNO3 was added while mixing the solution. Observations were recorded in the lab manual, and the waste was disposed of properly. The first confirmation test was the chloride test. Ten drops of the chloride solution was added to a centrifuge tube. 6 M HNO3 was added in a dropwise fashion to acidify the solution. Blue litmus paper was used to check the acidity of the solution. Then, five drops of 0.1 M AgNO3 was added to the solution. The tubes were centrifuged for two minutes; the liquid above the precipitate was then discarded. Three to four drops of 6 M NH4OH was added to the precipitate. If the precipitate dissolved, 6 M HNO3 is used to acidify the solution. If the precipitate was formed again, it is chloride. Observations were recorded in the lab manual. The second confirmation test was