: 210
Strong acid + strong base: steep pH jump from approximately 3 to 11 at equivalence. Equivalence pH = 7. Any indicator (methyl orange or phenolphthalein) works. Weak acid + strong base: gradual rise, buffer region around pKa, steep jump from approximately 7 to 11 at equivalence. Equivalence pH > 7 (8-9). Use phenolphthalein. Half-equivalence pH = pKa. Strong acid + weak base: steep drop from approximately 11 to 3 at equivalence. Equivalence pH < 7 (4-6). Use methyl orange. Weak acid + weak base: very gradual change, no sharp endpoint. No suitable indicator; use potentiometric titration. Key calculations: before equivalence (buffer region), at half-equivalence (pH = pKa), at equivalence (hydrolysis), after equivalence (excess strong reagent dominates). The buffer region extends approximately from 10% to 90% neutralisation. The steepest part of the curve occurs at the equivalence point. For polyprotic acids, there are multiple equivalence points and multiple buffer regions.