Calculate the pH during the titration of 20.0 mL of 0.500 M formic acid ( Ka = 1.8 × 10^-4) with 0.500 M NaOH. Calculate the pH after 0, 10.0, 20.0, and 30.0 mL of NaOH have been added, and sketch the titration curve.
Strategy

First, write the chemical equation for the titration and calculate the equivalence point. We will use an sRfc table to determine which species are present after adding titrant. Once we know which species are present, we will determine whether the system contains a strong acid or base, a weak acid or base, a buffer, or just water (including spectator ions). We already know how to calculate the pH of each of these systems.