14.8Acid-Base Titrations

Choosing an indicator means reading which pH-range (domain of the titration curve) an indicator's color-change interval falls within relative to the steep equivalence-point region — a domain/range reading task performed directly on the titration graph.

The titration curve's four named stages (initial, pre-equivalence gradual rise, equivalence sharp jump, post-equivalence gradual rise again) are a rate-of-change description of the pH-vs-volume function, and the text explicitly contrasts the gradual and abrupt regions — the same vocabulary algebra:3.4 teaches for reading a graph's behavior.

Every titration-curve point is a pH = −log[H3O+] or pOH = −log[OH⁻] evaluation from a stoichiometrically computed concentration, repeated at each titrant volume — the section is a sequence of logarithm evaluations chained to a stoichiometry calculation.

The half-equivalence-point shortcut (pH = pKa when [A⁻] = [HA]) and the indicator color-change analysis both reuse the Henderson-Hasselbalch log-of-a-quotient equation from buffers — without it a student has to redo a full ICE-table calculation at every titration stage instead of reading it off directly.