Final answer:
2)Half-equivalence point A titration curve illustrates pH changes during titration, including the buffering region, half-equivalence point, equivalence point, and endpoint. The buffering region is where the pH is resistant to change; the half-equivalence point is where pH equals the pKa; the equivalence point is where moles of acid and base are equal, and the endpoint is the indicator's color change.
Step-by-step explanation:
A titration curve is a graph that displays the pH changes of a solution as a titrant is added during a titration process. Here are the parts of a titration curve explained:Buffering region: This is a flat part of the curve where the solution resists pH change. It corresponds to the formation of a buffer, usually occurring at a pH range close to the pKa value of the weak acid being titratedHalf-equivalence point: At this point of the titration, half of the acid has been neutralized by the base. The pH at this point typically corresponds to the pKa of the weak acid, indicating the presence of equal concentrations of the weak acid and its conjugate base.Equivalence point: This is where the moles of titrant added are stoichiometrically equivalent to the moles osubstance present in the solution. For a strong acid-strong base titration, the pH at this point will be 7. For a weak acid-strong base titration, the pH will be greater than 7, while for a strong acid-weak base titration, the pH will be less than 7Endpoint: This is the point at which the indicator changes color, marking the end of the titration. It should ideally be as close as possible to the equivalence point to yield an accurate titration result.
The choice of an indicator is highly dependent on the expected pH at the equivalence point to ensure accurate detection of the endpoint of the titration.The equivalence point is the point on the titration curve where the moles of acid and base are stoichiometrically balanced, resulting in complete neutralization. In a strong acid-strong base titration, the equivalence point corresponds to a pH of 7. In a weak acid-strong base titration, the equivalence point may have a pH greater than 7.EndpoinThe endpoint of a titration is the point at which a chemical indicator changes color, indicating the completion of the titration. The choice of indicator depends on the expected pH at the equivalence point. For example, phenolphthalein is commonly used in acid-base titrations and changes from colorless to pink at a pH around 8.2.