Equipment

• Data collection system
• Red Tide device
• Cuvette
• Sensor extension cable
• 6 Large test tubes
• Test tube rack
• 10 mL Graduated cylinder
• 10 mL 0.1 M Iron (III) Chloride
• 10 mL 0.1 M Copper (II) Chloride
• 10 mL 0.1 M Cobalt (II) Chloride
• 10 mL 0.1 M Nickel (II) Chloride
• 10 mL 0.1 M Sodium Chloride
• Color chart
• Wash bottle with distilled water
• Marking pen

Procedure

1.  Set up the data collection system and red tide machine.
2.  Add 10 mL of the 5 solutions into 5 different labeled test tubes. They are all strong electrolytes.
3.  Observe the colors in the solution and notice that the cations are responsible for the different colors seen.
4.  Display the Absorbance on the y-axis of the graph and wavelength on the x-axis and start the data recordings.
5.  Rinse the cuvette with a small portion of the first solution and then fill the cuvette two-thirds of the way full. It is important to rinse the cuvette with the solution being tested to make sure that there isn't any other solution present in the cuvette because that will interfere with the results.
6.  Dispose of the solution and rinse the cell with water.
7.  Repeat steps 5-6 for each solution.
8.  Stop recording the data, display all the runs and  then print the graph.
9.  Clean up according to instructions.