In titration, the endpoint refers to the moment when the reaction between the two solutions is considered complete.

The endpoint is a critical stage in the titration process, marking the completion of the reaction between the titrant (the solution dispensed from the burette) and the analyte (the solution contained in the conical flask). This point is typically signaled by a color change in the solution, which occurs due to the presence of an indicator. An indicator is a substance that undergoes a visible color change at or near the endpoint of the reaction.

It is important to differentiate the endpoint from the equivalence point. While closely related, the equivalence point represents the theoretical completion of the reaction, where the number of moles of titrant is stoichiometrically equal to the number of moles of analyte. In contrast, the endpoint is the practical, observable moment when the reaction is deemed complete, which usually occurs very close to the equivalence point.

Accurately determining the endpoint is essential in titrations, as it enables the precise calculation of the analyte’s concentration. This calculation relies on measuring the volume of titrant needed to reach the endpoint. An incorrect determination of the endpoint can lead to significant errors in calculating the concentration, highlighting the importance of selecting an appropriate indicator.

In summary, the endpoint in a titration signifies the completion of the reaction between the two solutions, evidenced by a color change due to an indicator. This stage is crucial for accurately determining the concentration of the analyte.