Discussion for Lab 8 The purpose of this lab was to obtain the K a value by measuring the pH and preparing buffer solutions to see how they resist to pH change. In part one, our objective was to calculate the K a value for acetic acid by creating a titration curve and finding the equivalence point. We first set up an electric pH meter that we had to calibrate by using standard solutions with pH of 7 and 4 respectfully. Then we are added .1M NaOH to a burette and marked the initial volume while we poured 25.0 mL of .1M acetic acid into a beaker that contained a stir bar. Then, with the pH meter in the beaker, we added 1.0mL of NaOH to the acetic acid and recorded the pH at each portion of 1.0mL until we got the pH of 11.5. It took us 28 mL to change the initial pH of 2.5 to 11.5. We used Excel to graph our data out to see the visual effect of the steep rise in pH. This is pretty accurate because according to the lab manual, on average, the pH changes increases at a faster rate around 22mL. We calculated
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This note was uploaded on 04/15/2008 for the course CHEM 1A taught by Professor Van koppen during the Spring '07 term at UCSB.