Acid-Base Titration Curve – AP Chemistry

Learning Objectives

Analyze the pH curve for strong vs. weak acid titrations.

Identify the equivalence point where moles of acid equal moles of base.

Observe the half-equivalence point buffering region (\(pH = pK_a\)).

Key Equations

pH calculation:

\( pH = -\log[H^+] \)

Henderson-Hasselbalch (Buffer):

\( pH = pK_a + \log\left(\frac{[A^-]}{[HA]}\right) \)

Indicator

Phenolphthalein changes from colorless (pH < 8.2) to fuchsia/pink (pH > 10.0), perfectly capturing the steep equivalence jump.