DRAFT: This module has unpublished changes.

Equipment:

- Data collection system

- Colorimeter

- Cuvette

- Sensor extension cable

- Beakers (2), 100-mL

- Test tubes (6), large

- Test tube rack

- Graduated cylinder, 50-mL

- Pipet with pump or bulb, 10-mL

-Glass stirring rod

- 0.40 M copper (II) sulfate (CuSO4), 30 mL

- Marking pen

- Wash bottle with distilled water


Method:

1. Measure 30 mL of 0.40 M copper(II) sulfate stock solution into a 100-mL beaker

2. Measure 30 mL of distilled water into another 100-mL beaker

3. Label four clean, dry test tubes "1" through "4" and place them into a test tube rack. Label the fifth test tube "Stock" and the sixth test tube "Unknown"

4. Pipet 2.0, 4.0, 6.0, and 8.0 mL of the 0.40 M copper(II) sulfate solution into test tube 1 through 4, respectively

5. Wash the pipet and use it to deliver 8.0, 6.0, 4.0, and 2.0 mL of distilled water into test tubes 1 through 4 so that each test tube has 10.0 mL of solution

6. Thoroughly mix each solution with a stirring rod

7. Pour the remaining 0.40 M copper(II) sulfate solution into the "Stock" test tube to use as the fifth data point for your calibration

8. Put 10 mL of a solution of unknown concentration, obtained from your instructor, in your test tube labeled "Unknown"

9. Start a new, manually sampled data set

10. Measure the absorbance of the six solution following the steps below

a. Rinse the cuvette twice with a small portion of the first solution and then fill the cuvette two-thirds full. Wipe the cuvette clean and dry and place it into the colorimeter

b. After the reading stabilizes, record a data point

c. Dispose of the solution appropriately and rinse the cell thoroughly with water

d. When you have recorded all of your data, stop the data set

11. Save your experiment and clean up according to your teacher's instructions

DRAFT: This module has unpublished changes.