titration error
/ ty-TRAY-shun ER-ur /
Imagine braking a car the instant a traffic light turns red — you almost never stop on the exact line, ending up a hair short or a hair past. Titration error is that small overshoot or undershoot between when you stop a titration and when you truly should have.
Precisely, the titration error is the difference between the volume of titrant at the observed end point and the volume at the true equivalence point. It arises because the signal you watch (usually an indicator's colour change) does not flip at the exact stoichiometric moment.
It matters because it sets a floor on a titration's accuracy: a poorly matched indicator can leave a noticeable, systematic gap. The good news is that this error is usually small and correctable — you can measure it with a blank titration, or pick an indicator that changes right at the equivalence point.
If an indicator turns colour only after one drop too much has been added, the end point sits past the equivalence point and the result reads slightly high; running a blank titration reveals and removes that titration error.
The gap between where you stop and where you should — usually small, often correctable.
Titration error is mostly a systematic error tied to the indicator and method, separate from random reading scatter at the burette. Choosing an indicator whose colour change brackets the equivalence point is the main way to keep it small.