Potassium Hydrogen Burette Lab

Procedure: The first part of this lab involved the standardization of the base NaOH with potassium hydrogen phthalate, or KHP. First, about 400 mL of NaOH (10 M) were poured into the 600-mL beaker. This was used to fill the burette. The 50-mL burette was rinsed through twice with 5 mL of NaOH. Then, the burette was mounted on the ring stand using a burette clamp and filled to 0 mL. Some of the NaOH was drained to fill the tip of the burette. The initial volume of NaOH, rounded to two decimal places, was recorded on a piece of paper. Next, 0.750 g of KHP (unknown molarity) in a weighing dish were weighed on the balance and poured into a 250-mL Erlenmeyer flask. This measurement was recorded on the piece of paper. Measured with a 100-mL graduated
The magnetic stirrer plate and flask were once again placed under the burette, and the height of the burette was readjusted. Then, with the stirrer plate turned on, the HCl solution was titrated until it became a pale pink color that lasted at least 30 seconds. Once the titration was completed, the final burette reading was recorded. Afterwards, this process was repeated two more times, starting out with refilling the burette and ending with completing the titration and recording the measurements. Lastly, the moles of NaOH, moles of HCL, molarity of HCL, and average molarity for the three samples were calculated and recorded on the piece of paper. Then, the Erlenmeyer flask, stirrer bar, 50-mL beaker, and 10-mL graduated cylinder were washed out and dried. In the last part of the lab, an unknown acetic acid solution was analyzed. This portion of the lab followed the same steps listed in the second part; however, an acetic acid solution (unknown molarity) was used in place of the HCl solution. Once again, three trials were completed with 10 mL of acetic acid. Finally, the moles of NaOH, moles of acetic acid, molarity of the acetic acid, and average molarity for the three samples were calculated and recorded on the piece of