Prepare three vinegar samples in three separate Erlenmeyer flasks, the vinegar in each flask is added with a 5 mL volumetric pipet, so the volume of vinegar is 5.00 mL in each flask. Add three drops of phenolphthalein indicator to each flask. You will add the standard 0.2020 M NaOH solution to the buret. The buret can hold up to 50.00 mL.
Sample titrations and data:
Sample 1 – Fill the buret with the NaOH solution to the line at the top of the buret 0.00 mL - YES it's at 0.00 when full - so your initial volume is 0.00 mL. Titrate by adding the NaOH drop-wise into the flask and swirling after each addition. You are finished when the indicator in the solution turns pink, at that point the final reading on the buret is 22.10 mL.
Sample 2 – The initial volume reading for sample 2 is 22.10 mL (which is the final volume from the previous titration), and after titrating the final volume reading is 43.88 mL.
Sample 3 – At this point, we need more NaOH solution in the buret, so we add enough that the initial volume for sample 3 is 25.00 mL, and after titration the final volume is 46.69 mL.
That is all the data you need, once the first three rows of your data table are complete, you are ready to begin your calculations and determine the concentration of acetic acid in your vinegar samples.