6-150 Ml Beakers And DI Water

6 – 150 mL beakers were set up and a stir bar placed in each beaker. Each beaker was labeled with DI water, or the pH buffer that was going to be put in the beaker. 50 mL of each of the 5 assigned pH buffers and DI water were obtained using a graduated cylinder and placed in the corresponding beaker. Each of the beakers containing the pH buffer and DI water were placed on the stir plate and the stir plate turned on. A sample of salicylic acid was obtained in a weigh boat and taken back to the lab bench. While mixing the solutions with the magnetic stirrer, small amounts of salicylic acid were added to the solutions. Salicylic acid was added in small amounts to the solutions and stirred until a saturated solution was achieved. 3 – 100 mL
A syringe filter was placed on the syringe and 8 mL of solution pushed back into the beaker and the remaining 2 mL placed into a properly labeled vial. Each saturated solution was filtered the same way and placed into a labeled vial. 6 – 10 mL flask were obtained and labeled with DI water or the pH buffer that was being used. Using a micropipette, 100 µL of each sample was collected and placed into a labeled 10 mL flask. The 10 mL flask was then filled with DI water using a disposable pipet. The flask was then covered with parafilm and inverted to make sure the solution was mixed. The calibration curve of Salicylic Acid was prepared before lab and given to all students. The UV-Vis was turned on previously in lab to let the system equilibrate. The UV-Vis was set to the correct desired wavelength, 300 nm. The cuvette was obtained and cleaned using DI water and a kimwipe. The cuvette was then filled three-fourths full with DI water to run a blank. The absorbance was measured and the cuvette removed and cleaned. The cuvette was then filled with a saturated solution and placed in the UV-Vis. The absorbance was measured and recorded for each saturated solution in Table 2-1. This process was repeated until an absorbance for each saturated solution was