Titration endpoint
= 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 $\widehat n_A=c_BV_{\mathrm{end}}$ and
$$
\frac{\widehat n_A-n_A}{n_A}=\frac{\Delta V}{V_{\mathrm{eq}}}.
$$
Thus 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.