Assume that 30.0 mL of a 0.10 M solution of a weak base B that accepts one proton is titrated with a 0.10 M solution of the monoprotic strong acid HA. (a) How many moles of HA have been added at the equivalence point?

Verified step by step guidance

1. Identify the initial conditions: You have 30.0 mL of a 0.10 M solution of a weak base B.
2. Calculate the initial moles of the weak base B using the formula: \( \text{moles of B} = M \times V \), where \( M \) is the molarity and \( V \) is the volume in liters.
3. Recognize that at the equivalence point, the moles of the weak base B will equal the moles of the strong acid HA added.
4. Since the molarity of HA is the same as that of B (0.10 M), the volume of HA added at the equivalence point will be the same as the initial volume of B.
5. Calculate the moles of HA added at the equivalence point using the same formula: \( \text{moles of HA} = M \times V \), where \( M \) is the molarity of HA and \( V \) is the volume of HA added.

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 (in this case, the strong acid HA) to a solution containing the analyte (the weak base B) until the reaction reaches its equivalence point, where stoichiometrically equivalent amounts of acid and base have reacted.

Equivalence Point

The equivalence point in a titration is the stage at which the amount of titrant added is exactly enough to completely neutralize the analyte in the solution. For a weak base titrated with a strong acid, this point is characterized by a complete reaction between the base and the acid, resulting in the formation of water and a salt, and is crucial for calculating the moles of titrant used.

Molarity and Moles

Molarity (M) is a measure of concentration defined as the number of moles of solute per liter of solution. To find the number of moles of a substance, you can multiply the molarity of the solution by its volume in liters. In this question, the molarity of the strong acid HA and the volume at the equivalence point will help determine how many moles of HA have reacted with the weak base B.