Acid Base Equilibria In part one, solution was slowly titrated until an obvious change in pH occurred. On a pH titration graph at the point of equivalence point there is a great increase in pH. Using this fact and a pH meter the equivalence point was determined. The Ka value was a little high because the exact value of equivalence was passed during the titration. The formula for this part is CH 3 OOH H+CH 3 COO. In Part one the calculated Ka’s for the solutions are very close to the actual Ka. 2.5x10^-5, 1.9x10^-5, and 2.6x10^-5 are all very close to the actual Ka of 1.76x10^-5. The Calculated Ka’s are higher because of measuring and rounding error in the experiment. The graduated cylinder only measures to .1ml and the pH meter only reads to one decimal place. Adding that to rounding error can explain why the Ka is larger than its actual value. In the first measured pH versus actual pH there was 0% difference indicating that the two pH’s are equal, and in the second there was only a 5% difference. This indicates that the
This is the end of the preview. Sign up
access the rest of the document.
This note was uploaded on 06/09/2008 for the course CHEM 1AL taught by Professor Hooker during the Spring '07 term at UCSB.