Metal Flame Emission — Lab Prep

Source: Smaa Koraym at Johns Hopkins University, MD, USA

  1. Lab Preparation for Metal Flame Emission Testing

    Here, we show the laboratory preparation for 10 students working in groups of 5, with some excess. Please adjust quantities as needed.

    • Put on a lab coat, safety glasses, and nitrile gloves.
    • Barium, copper, and strontium require special disposal, so place an appropriate waste container and a wash bottle of deionized water in the waste hood.
    • Prepare a spectrophotometer for each student group. Confirm that the devices are working and charged before distributing them to the student's fume hoods.
    • Set a Bunsen burner, a length of latex tubing, a striker, a sparkler in a 250-mL Erlenmeyer flask, and a 400-mL glass beaker in the main instructor's hood.
    • Prepare the metal salts. For each student group, place 6 small test tubes in a rack.
    • Label the 6 tubes as 'Na', 'K', 'Li', 'Ba', 'Sr', and 'Cu'. Prepare an extra rack as a backup.
    • Obtain the metal salts and a few paper towels to catch any spills. Use a small disposable spatula to fill each Na tube with NaCl to a depth of about 2 mm. Discard the spatula afterward.
    • Fill the remaining tubes in the same way using a clean spatula for each metal to prevent cross-contamination.
    • Place a rack of filled test tubes at each fume hood. Store the extra rack in the instructor's hood and clean up any traces of spilled salts.
    • Distribute a Bunsen burner and striker to each fume hood.
    • Lastly, just before the lab, fill a 400-mL beaker with deionized water for each student group and place 6 cotton-tipped applicators tip down in each beaker. Set one at each fume hood.