SAFETY NOTES: The solutions being used are acidified. Be sure to wear your goggles and wash hands immediately if your skin begins to itch or tingle.
GENERAL INSTRUCTIONS: Each student will work with one partner. Before Starting make sure the Genesys-20 Spectrometer is turned on and set to 447 nm.
| Part 1: Making Solutions to Determine the Extinction Coefficient | |
 |
In clean dry 100 mL beakers, collect 50 mL of 0.200M acidified Fe(NO3)3 and 0.001M KSCN. |
 |
Using a Mohr pipet create the solutions A-E described in the background. Be very careful not to contaminate your stock solutions. If a rust color should form in the pipet it is contaminated. Clean it and remake the solution you were working on. Note: Each solution should have the exact same total volume. |
| Part 2: Measuring the Absorbance | |
 |
Collect a cuvette from the front counter. Make sure it is clean and dry. |
 |
Using a Blank of 0.200M Fe(NO3)3 Rinse the cuvette with the blank and then fill the cuvette with blank and zero the spectrometer. |
 |
Rinse the cuvette with the first solution and then fill it with the solution. Measure the Absorbance and record it in your notebook. Repeat the process until all the samples are measured |
| Part 3: Making Solutions to Determine the Equilibrium Constant | |
|
In clean dry 100 mL beakers, collect 50 mL of 0.002M acidified Fe(NO3)3 and 0.002M KSCN. |
|
Using a Mohr pipet create the solutions F-J described in the background. Be very careful not to contaminate your stock solutions. If a rust color should form in the pipet it is contaminated. Clean it and remake the solution you were working on. Note: Each solution should have the exact same total volume. |
| Part 4: Measuring the Absorbance | |
|
Collect a cuvette from the front counter. Make sure it is clean and dry. |
 |
Using a Blank of 0.002M Fe(NO3)3 Rinse the cuvette with the blank and then fill the cuvette with blank and zero the spectrometer. |
|
Rinse the cuvette with the first solution and then fill it with the solution. Measure the Absorbance and record it in your notebook. Repeat the process until all the samples are measured |
