Answer:
A) The equivalence point where the amount of acid equals the amount of base during any acid-base titration.
Step-by-step explanation:
An acid-base titration is used to determine the unknown concentration of an acid or base by neutralizing it with an acid or base of known concentration. Using the stoichiometry of the reaction, the unknown concentration can be determined. It makes use of the neutralization reaction that occurs between acids and bases and the knowledge of how acids and bases will react if their formulas are known.
Titrations are reactions between specifically selected reactants—in this case, a strong base and a weak acid. A titration curve reflects the strength of the corresponding acid and base, showing the pH change during titration. The titration curve demonstrating the pH change during the titration of the strong base with a weak acid shows that at the beginning, the pH changes very slowly and gradually. This indicates the formation of a buffer system as the titration approaches the equivalence point.
At the equivalence point and beyond, the curve is typical of a titration of, for example, NaOH and HCl. When the NaOH is in excess, the pH change is the same as in any system dominated by NaOH.