🤓 Based on our data, we think this question is relevant for Professor Gavva's class at UTD.

Of the following solutions, which has the greatest buffering capacity?

a. 0.100 M NH_{3} and 0.455 M NH_{4}CI

b. 0.087 M NH_{3} and 0.088 M NH_{4}CI

c. They are all buffer solutions and would all have the same capacity.

d. 0.234 M NH_{3} and 0.100 M NH_{4}CI

e. 0.543 M NH_{3} and 0.555 M NH_{4}CI

We’re being asked which of the given solutions will have the greatest buffering capacity.

The maximum buffering capacity of a solution is when the pH of the solution is equal to pK_{a} and the buffer range of a solution is pH = pKa ± 1.

•** maximum buffering capacity: pH = pK _{a}**

•

Recall the Henderson-Hasselbalch equation:

$\overline{){\mathbf{pH}}{\mathbf{=}}{{\mathbf{pK}}}_{{\mathbf{a}}}{\mathbf{+}}{\mathbf{log}}\left(\frac{\mathbf{conjugate}\mathbf{}\mathbf{base}}{\mathbf{weak}\mathbf{}\mathbf{acid}}\right)}$

• the **ideal buffer** is when the amount of conjugate base is equal to the amount of the weak acid.

**[conjugate base] = [weak acid]**