Final answer:
The calculation of pH during a titration of weak acid with strong base involves using the ICE table, acid dissociation constant (Ka), and considering the ionization of the conjugate base post equivalence point. Initial pH and pH changes at various titration stages (including the equivalence point) are calculated from the concentration and strength of the acid and base.
Step-by-step explanation:
The question involves calculating the pH at different points during the titration of a weak acid (acetic acid) with a strong base (potassium hydroxide). We use the ICE table and the given acid dissociation constant (Ka) for acetic acid to calculate the initial pH and the pH at various points in the titration, including the equivalence point.
For the initial pH calculation of acetic acid before any KOH is added, we apply the ICE table approach:
[H3O+] = √(Ka × [HC2H3O2 initial])
For 0.11 M acetic acid, this gives:
[H3O+] = √(1.7 × 10^-5 × 0.11) = 1.39 × 10^-3 M
pH = -log(1.39 × 10^-3) = ~2.85
At the halfway point to the equivalence point, the pH equals the pKa of acetic acid. At the equivalence point, we compute the pH factoring in the acetate ion's base ionization. If there's excess KOH, the pH is primarily determined by the excess strong base.