Compare the titration of a strong, monoprotic acid with a strong base to the titration of a weak, monoprotic acid with a strong base. Assume the strong and weak acid solutions initially have the same concentrations. Indicate whether the following statements are true or false. (a) More base is required to reach the equivalence point for the strong acid than the weak acid.

Verified step by step guidance

1. Understand the concept of titration: Titration is a technique where a solution of known concentration (titrant) is used to determine the concentration of an unknown solution. In this case, a strong base is used to titrate both a strong and a weak acid.
2. Identify the 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 sample. For both strong and weak acids, this means the moles of base added equals the moles of acid present.
3. Compare the moles of acid: Since both the strong and weak acid solutions have the same initial concentration and volume, they contain the same number of moles of acid.
4. Determine the amount of base required: Since the equivalence point is reached when the moles of base equals the moles of acid, and both acids have the same number of moles, the same amount of base is required to reach the equivalence point for both the strong and weak acid.
5. Conclude the statement: The statement 'More base is required to reach the equivalence point for the strong acid than the weak acid' is false, as the same amount of base is required for both.

Key Concepts

Titration

Titration is a quantitative analytical technique used to determine the concentration of a solute in a solution. It involves the gradual addition of a titrant (a solution of known concentration) to a sample until a reaction reaches its equivalence point, where the amount of titrant equals the amount of substance in the sample. The shape of the titration curve and the pH at the equivalence point vary depending on whether the acid or base is strong or weak.

Strong vs. Weak Acids

Strong acids, like hydrochloric acid (HCl), completely dissociate in water, releasing all their protons (H+), while weak acids, such as acetic acid (CH3COOH), only partially dissociate. This difference in dissociation affects the pH of the solution and the amount of base required to neutralize the acid. In titrations, strong acids lead to a sharp pH change at the equivalence point, whereas weak acids result in a more gradual change.

Equivalence Point

The equivalence point in a titration is the stage at which the amount of titrant added is stoichiometrically equivalent to the amount of substance in the sample. For strong acid-strong base titrations, the pH at the equivalence point is neutral (pH 7), while for weak acid-strong base titrations, the pH is greater than 7 due to the formation of a weak conjugate base. This difference influences the volume of titrant needed to reach the equivalence point.