📚 Topic Summary
Titration curves illustrate the change in pH during the titration of an acid or a base. For strong acids and bases, the pH changes drastically near the equivalence point. However, weak acids and weak bases exhibit more complex titration curves due to their partial dissociation. The key features to analyze are the initial pH, the buffer region (where the pH changes gradually), the half-equivalence point (where pH = pKa), the equivalence point, and the region after the equivalence point. Understanding these features allows us to determine the concentration and strength of the weak acid or base.
🧪 Part A: Vocabulary
Match the term with its correct definition:
- Term: Equivalence Point
- Term: Half-Equivalence Point
- Term: Buffer Region
- Term: pKa
- Term: Titration
- Definition: The point in a titration where the amount of titrant added is chemically equivalent to the amount of analyte.
- Definition: The region in a titration curve where the pH changes gradually, resisting drastic changes upon addition of acid or base.
- Definition: The negative base-10 logarithm of the acid dissociation constant ($K_a$).
- Definition: A process in which a solution of known concentration is used to determine the concentration of another solution.
- Definition: The point in a titration where half of the weak acid (or weak base) has been neutralized. At this point, pH = pKa.
Match the term numbers to definition numbers.
📝 Part B: Fill in the Blanks
Complete the following paragraph using the words provided below.
The titration curve of a weak acid titrated with a strong base shows a gradual change in pH within the __________ region. At the __________ point, the pH is equal to the pKa of the weak acid. Beyond the __________ point, the pH is primarily determined by the excess strong base added.
Word Bank: buffer, half-equivalence, equivalence
🤔 Part C: Critical Thinking
Explain how the titration curve of a weak base differs from that of a weak acid. What similarities and differences can be observed? Be sure to mention where the buffer region would be most effective.