Which term describes the point in a titration at which enough titrant has been added to react exactly with the substance in solution being titrated?

• A. Endpoint
• B. Equivalence Point
• C. Titration
• D. Buffer

Answer: (B)

Equivalence point is the moment in a titration when enough titrant has been added to react with the substance in solution in exact stoichiometric amounts. At this point the reaction between analyte and titrant is complete, with no excess of either reactant remaining (aside from minor ions). In many acid–base titrations this shows up as a sharp change in pH on the titration curve. The endpoint, indicated by a color change of an indicator, should align closely with the equivalence point if the indicator is chosen appropriately, but it can occur slightly before or after. Titration is the overall process of adding titrant and tracking the reaction, while a buffer is a solution that resists pH changes due to the presence of a weak acid and its conjugate base (or a weak base and its conjugate acid).