Common Ion Effect and Buffers in Acid-Base Equilibria

Recall, after doing this ungraded homework for practice, you need to complete the supplemental graded homework problems on D2L

OBJECTIVES: After having completed this unit, students should be able to:

1. Define common ion effect and explain how it affects an acid/base or solubility equilibrium.
2. Define, explain, and be able to identify buffer solutions.
3. Explain how buffer solutions are prepared and calculate the amount of the components required to prepare a buffer given pH.
4. Using chemical equations, describe how a buffer solution can resist a change in pH when a small amount of H⁺ (from strong acid) or OH^– (from strong base) is added.
5. Calculate the pH of a buffer solution starting with an initial concentration of the buffer components and K_a or using the Henderson-Hasselbalch equation using the pK_a and the initial buffer component concentrations.
6. Calculate the change in pH of a buffer solution of known composition caused by adding a small amount of strong acid (H⁺) or strong base (OH^–).
7. Define buffering capacity and given a choice of buffers select which one has a higher buffering capacity.

Reading and Homework Exercises

Table of Contents from: OpenStax Chemistry 2e: Section 14.6

14.6 Buffers

Also, read this link from LibreTexts to better understand the common ion effect, paying special attention to the section “Common ion effect with weak acids and bases”

Practice

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special question 16