Experiment 7: Ksp of Ca(OH)2
The primary objective in this experiment was to determine the solubility product constant of a calcium hydroxide that was very slightly soluble. At the conclusion of the experiment, the results determined that as the concentration of the medium increases, the solubility of the precipitate increases. Using the solubility product constant, it was determined that the solubility of calcium hydroxide precipitate decreased when dissolved in a medium possessing a common ion.
Experiment and Observation
For the first part of the experiment, 5 drops of 0.1 M calcium nitrate were placed in a 6-well row of a 24-well plate. 5 drops of distilled water were placed in wells 2 through 6. A toothpick was used to stir the calcium nitrate and contents of well 2. The calcium nitrate was added to halve the solution. This process was completed for the remaining wells to halve each from the initial well. 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. 5 drops of 0.10 M sodium hydroxide were placed in wells 1 and 2, and 5 drops of distilled water were placed in wells 2 through 6. A toothpick was used to stir the mixture in well 2, resulting in 0.05 M of sodium hydroxide. A pipet was used to extract the solution from well 2 and 5 drops were added to well 2. The dilution process was repeated for the remaining wells, as completed in part 1. After determining if a precipitation had occurred, the solutions were properly disposed of, all materials were cleaned and stored...