The graphs labeled (a) and (b) show the titration curves for two equal-volume samples of monoprotic acids, one weak and one strong. Both titrations were carried out with the same concentration of strong base.
(ii) Which graph corresponds to the titration of the strong acid and which one to the titration of the weak acid?

Key Concepts

Titration Curves

Titration curves graphically represent the pH changes of a solution as a titrant is added. For strong acids, the curve shows a steep increase in pH near the equivalence point, while weak acids exhibit a more gradual slope due to their incomplete dissociation. Understanding these curves is essential for identifying the nature of the acid being titrated.

Strong vs. Weak Acids

Strong acids completely dissociate in solution, resulting in a high concentration of hydrogen ions (H+) and a low pH. In contrast, weak acids only partially dissociate, leading to a higher pH at equivalent concentrations. This fundamental difference affects the shape of their titration curves, making it crucial to distinguish between them in titration experiments.

Equivalence Point

The equivalence point in a titration is reached when the amount of titrant added is stoichiometrically equivalent to the amount of substance in the solution. For strong acids, this point is characterized by a sharp change in pH, while for weak acids, the change is more gradual. Recognizing the equivalence point helps in determining the strength of the acid being analyzed.