Results and Discussion For the first part of the experiment (Part A), five different 100 mL volumetric flasks were each filled with 1,2,3,4 and 5 mL of iron (II) solution. Then 5 mL of YY ligand, were poured to each of the five flasks. Each flask had 5 mL of 2M sodium acetate and 4 mL of 3M NH2OH. Then the whole solution was diluted up to the 100 mL fill mark with distilled water. This was the solution that was used in order to obtain the absorption spectrum for each of the different iron (II) ligand examples different flasks.
Allow the mixture to cool for a few minutes then filter it, using either gravity or vacuum filtration. (We shall be using vacuum filtration.) Wash the residue in the funnel once with a little water and collect all the filtrate. 4. Pour all the filtrate and washings into a 250cm3 volumetric flask.
Next, 50 mL of distilled was placed into the 150 mL. Twenty drops of Bromothymol blue were added to the 150 mL beaker solution. The pH was then recorded. Five mL of this solution was transferred into three separate 100 mL beakers. In one of these beakers, 1 mL of HCl was added to the solution, making this the “Yellow” beaker.
Using another 125-mL flask, 60-mL of 0.3622 M potassium hydroxide in ethanol was deposited. Both flasks were clamped in a temperature-controlled bath regulated at 50.0˚C. The solutions were then set in the temperature bath for ten minutes to equilibrate. An empty 250-mL Erlenmeyer flask was also clamped in the same water bath. In another flask 50-mL of ice water was deposited with three-drop phenolphthalein.
After heating, the mixture was cooled to room temperature and filtered by vacuum filtration into a fritted funnel to yield a purple product. The product was washed 3 times with (5mL) portions of chilled 6M HCL, then Ethanol, and lastly with acetone. The resulting product was placed into a vial and left to dry in a vacuum desiccator for 1 week and weighed the next week. The yield was 6.029g. The second experiment, procedure 1, combined [Co(NH3)5 (H2O)]Cl2 (0.0060M, 1.52g) and (25mL) of distilled water to an 125mL Erlenmeyer flask.
2. A 250mL volumetric flask was washed three times with distilled water. 3. A funnel was used to wash the crystals in to the volumetric flask with the aid of the glass rod and the wash bottle. All the washings were placed into the volumetric flask.
5 drops of water and 5 drops of the calcium nitrate solution were pipetted for each well. For the second part of the experiment, 5 drops of 0.1 M sodium hydroxide were added to wells 1 through 6. The well plate was left for 5 minutes allowing the precipitates to form. Using Table 2 given in the lab manual, the solubility product was calculated and the experiment results were compared to the accepted values. For the third part of the experiment, the process of part 1 was repeated using sodium hydroxide.
When the liquid above the precipitate was clear, the solution was tested for completeness of precipitation when a few drops of BaCl2 solution were added from a pipette. Next, filter paper was place into the funnel and streamed with distilled water. A clean 400mL beaker is placed under the funnel and the precipitate was filtered through. When all the precipitate was filtered and removed from the beaker the residue is washed with distilled water. About 3mL of the wash water is collected in a small test tube.