Question: Chemistry Lab Report: Experiment #11Chemical Equilibrium:Determination of an Equilibrium Constant

Equipment:

1. 6 cuvettes (1 for Blank, 4 for Part A, 1 for Part B)
2. Micropipette and tip.
3. SpectroVis Plus
4. Two 50ml beakers to hold Fe³⁺ and SCN^-
5. 50 ml beaker for distilled water

Setting up the SpectroVis Plus:

1. Use the black USB cable to connect the spectrophotometer to the computer
2. Open the LoggerPro program
3. Wait until the spectrum of color is observed on the screen (establish communication)

Experiment (Part A):

1. Fill an empty cuvette (2/3) with distill water
2. Place it on the spectrophotometer holder where the transparent surface should face the light (arrow)
3. Click on the experiment à calibration
4. Click on finish à ok
5. We will be filling 4 cuvettes with the following (Each cuvette should hold a total volume of 3ml) See steps 8/9/10/11:

6. Get your micropipette and fit it with the appropriate tip.
7. For your information:
   1. 1.5 ml corresponds to 750 micro liters twice
   2. 1.2 ml corresponds to 600 micro liters twice
   3. 0.6 ml corresponds to 600 micro liters once
   4. 0.3 ml corresponds to 300 micro liters once
8. For cuvette #1:
   1. Add 1.5ml of Fe³⁺ using the micropipette into the cuvette
   2. Rinse the tip with water by collecting water, then disposing it in the waste.
   3. Add 0.6ml of SCN^- using the micropipette into the cuvette
   4. Rinse the tip with water by collecting water, then disposing it in the waste.
   5. Add 0.9ml of H2O using the micropipette into the cuvette
9. For cuvette #2:
   1. Add 1.5ml of Fe³⁺ using the micropipette into the cuvette
   2. Rinse the tip with water by collecting water, then disposing it in the waste.
   3. Add 0.9ml of SCN^- using the micropipette into the cuvette
   4. Rinse the tip with water by collecting water, then disposing it in the waste.
   5. Add 0.6ml of H2O using the micropipette into the cuvette
10. For cuvette #3:
    1. Add 1.5ml of Fe³⁺ using the micropipette into the cuvette
    2. Rinse the tip with water by collecting water, then disposing it in the waste.
    3. Add 1.2ml of SCN^- using the micropipette into the cuvette
    4. Rinse the tip with water by collecting water, then disposing it in the waste.
    5. Add 0.3ml of H2O using the micropipette into the cuvette
11. For cuvette #4:
    1. Add 1.5ml of Fe³⁺ using the micropipette into the cuvette
    2. Rinse the tip with water by collecting water, then disposing it in the waste.
    3. Add 1.5ml of SCN^- using the micropipette into the cuvette
    4. DO NOT ADD WATER
12. Remove the blank (distill water) from the spectrophotometer and add cuvette #1.
13. Press Collect.
14. Remove cuvette #1 and add cuvette #2.
15. Press Collect.
16. Remove cuvette #2 and add cuvette #3.
17. Press Collect.
18. Remove cuvette #3 and add cuvette #4.
19. Press Collect.
20. Make sure you have four Curves.
21. Now export your data as CSV. (File -> Export as -> CSV.)

Experiment (Part B):

1. Press on Data -> Clear All data
2. Grab another empty cuvette and fill it with:
   1. Add 0.3ml of SCN^- using the micropipette into the cuvette
   2. Rinse the tip with water by collecting water, then disposing it in the waste.
   3. Add 2.7ml (900 micro liters three times) of CONCENTRATED Fe³⁺ using the micropipette into the cuvette.
3. Place it in the Spectrophotometer and press collect.
4. Now remove 750 micro liters (0.75ml) of the solution_­ out of the cuvette and add 750 micro liters (0.75ml) of Nitric acid into the cuvette.
5. Now close the cuvette with a cuvette lid and gently flip the cuvette upside down for mixing.
6. Put it back in the spectrophotometer and press collect à store latest run
7. Now remove 1000 micro liter (1ml) out of the cuvette and add 1000 micro liter (1ml) of Nitric acid in to the cuvette
8. Now close the cuvette with a cuvette lid and gently flip the cuvette upside down for mixing.
9. Put it back in the spectrophotometer and press collect à store latest run
10. Now remove 750 micro liters (0.75ml) of the solution  twice _­ out of the cuvette and add 750 micro liters (0.75ml) of Nitric acid  twice in to the cuvette.
11. Now close the cuvette with a cuvette lid and flip the cuvette upside down gently.
12. Put it back in the spectrophotometer and press collect à store latest run
13. Repeat step 10, 11, 12 one more time.
14. Make sure you have Five Curves.
15. Now export your data as CSV. (File -> Export as -> CSV.)

https://apaxresearchers.com/storage/files/2023/04/04/9667-eAi_08_24_44_samplelabreport.pdf

https://apaxresearchers.com/storage/files/2023/04/04/9667-8m1_08_24_36_experiment11-chem117.pptx

https://apaxresearchers.com/storage/files/2023/04/04/9667-FbX_08_24_27_lab11-2.xlsx