What is the midpoint of the vertical portion of the titration curve called, indicating neutralization?

• A. Endpoint
• B. Equivalence Point
• C. Half-equivalence point
• D. Titration Point

Answer: (B)

In a titration curve, the steep, vertical region shows the neutralization happening most rapidly as the titrant is added. The point where the amount of titrant added equals the amount of analyte present is the equivalence point, marking the complete consumption of one reactant by the other. The midpoint of that steep portion is the equivalence point itself, which is why this point indicates neutralization. For a strong acid–strong base titration, the pH at this point is about 7, while other combinations shift that value depending on which reactant is in excess. The observed endpoint is just the color change of an indicator and may align with the equivalence point but isn’t the exact neutralization point. The half-equivalence point occurs earlier in the curve, where half of the analyte has been titrated and the pH equals the pKa in appropriate cases, and it is not the midpoint of the vertical region.