During a titration lab where 0.1 N of NaOH is added to 20 mL of acetic acid with the same concentration, the equivalence point occurred after adding about 70ish milliliters of NaOH (different peers acquired different values, ranging from 65 mL and 75 mL of NaOH). This completely puzzled me, because after calculating a theoretical titration curve, my equivalence point occurred after adding about 20 mL of NaOH.
My teacher could not explain why this happened, except that acetic acid can act as a buffer – but how do you calculate this and incorporate it into a theoretical titration curve? I just don't understand how 20 mL of acetic acid would require 70 mL of NaOH to neutralise it (both have the same concentration).
