 Titration endpoint

A titration endpoint is the experimentally assigned point indicated by a specified signal: for example, a persistent color of a pH indicator, or a feature extracted from a potentiometric titration. An equivalence point is defined by stoichiometry; an endpoint estimates its location. State the signal rule and its repeatability. A fleeting local color where a drop enters an unmixed sample need not satisfy the rule for the mixed sample.

Define the endpoint offset $\Delta V=V_{\mathrm{end}}-V_{\mathrm{eq}}$. For one-to-one neutralization, using the endpoint without correction gives inferred acid inventory ${\hat{n}}_A=c_B{V}_{\mathrm{end}}$ andThus an illustrative $0.05\mathrm{mL}$ overshoot at $V_{\mathrm{eq}}=10.00\mathrm{mL}$ overestimates the inventory by $0.5\%$. Repeatedly reaching the same color can reduce scatter while retaining this systematic offset. This example stipulates an offset; it is not a measured drop size.