The equivalence point in a titration is a critical moment where the quantity of titrant added is sufficient to completely react with the analyte, the substance being analyzed.

In more detail, the equivalence point represents the precise instant during a titration when the analyte has fully reacted with the titrant. This moment is often marked by a noticeable change in the color of the solution, which occurs due to the presence of an indicator. An indicator is a chemical that changes color at or near the equivalence point, providing a visual signal that the reaction is complete.

It is important to distinguish between the equivalence point and the endpoint, as they are commonly mistaken for one another. The endpoint refers to the moment when the indicator changes color, which ideally aligns with the equivalence point. However, due to the inherent limitations of indicators, the endpoint may not always coincide precisely with the equivalence point. This difference can lead to titration errors, defined as the discrepancy between the actual equivalence point and the observed endpoint.

The concept of the equivalence point is essential in quantitative chemical analysis, especially in acid-base titrations. In such titrations, the equivalence point occurs when the moles of acid are equal to the moles of base in solution. At this juncture, the pH of the solution typically reaches $7$, indicating a neutral solution. It is important to note, however, that the pH at the equivalence point can vary based on the strengths of the acid and base involved.

In redox titrations, the equivalence point is achieved when the moles of the oxidizing agent equal the moles of the reducing agent. Similarly, in complexometric titrations, it occurs when the moles of metal ions are equal to the moles of the ligand.

Understanding the equivalence point is vital for accurately determining the concentration of a solution during a titration. By knowing the volume of titrant required to reach the equivalence point and its concentration, one can calculate the concentration of the analyte using the stoichiometry of the chemical reaction involved.