posted by Jake on .
Construct the data chart and the pH curve for the titration of 25 mL of 0.1 M CH3COOH with 0.1M NaOH. Add the titrant 1 mL at a time and calculate the pH after each addition
We can't draw pictures/graphs on the board. Here is how the titration of a weak acid with a strong base looks. Scroll down about half-way.
The secret to calculating the pH at selected points along the curve comes with recognizing what one has in the titration flask.
At zero mL, the solution is just pure acetic acid. In this case, we have 0.1M CH3COOH; I'm sure you know how to calculate that. At the equivalence point, you have the hydrolysis of the salt, in this case, CH3COONa. That is done, and I'm sure you have done these, by CH3COO^- + HOH ==> CH3COOH + OH^-
Set up an ICE chart and solve for OH^-
Kb (Kw/Ka) = (CH3COOH)(OH^-)/(CH3COO^-)
At all point between zero and the equivalence point, in this case at each 1 mL point, use the Henderson-Hasselbalch equation to calculate pH. At all point after the equivalence point, the pH is determined by the excess NaOH added. If you need further assistance, please post your work and explain where you are on the curve and what you don't understand.