Final answer:
Titration curves for strong acids/bases differ from those of weak acids/bases because strong acids/bases fully dissociate, causing a steep pH change, while weak acids/bases only partially dissociate, which leads to a more gradual pH change at the equivalence point, thus altering the curve's shape.
Step-by-step explanation:
The reason why titration curves for strong acids/bases are different from those involving weak acids/bases lies in the degree of dissociation of the acids and bases in water. When a strong acid or strong base is titrated, they fully dissociate in water, leading to a rapid change in pH near the equivalence point and producing an S-shaped curve. This rapid pH change results in a steep curve on the graph because the addition of a small amount of titrant causes a significant pH change. In comparison, weak acids or bases do not completely dissociate in water. Therefore, when titrated with a strong counterpart, the pH change around the equivalence point is more gradual due to the partial dissociation and the buffering effect of the weak acid or weak base. This results in a titration curve that rises more gently around the equivalence point. Furthermore, the curve's shape can be affected by the Ka or Kb values, which represent the strength of the weak acid or base.