he maximum buffering capacity of a solution is when the pH of the solution is equal to pKa and the buffer range of a solution is pH = pKa ± 1.
• maximum buffering capacity: pH = pKa
• buffering range: pH = pKa ± 1
Recall the Henderson-Hasselbalch equation:
Which of the following acids should be used to prepare a buffer with a ph of 4.5?
A. HOC6H4OCOOH, Ka = 1.0 x 10-3
B. C6H4(COOH)2, Ka = 2.9 x 10-4
C. CH3COOH, Ka = 1.8 x 10-5
D. C5H5CCOOH, Ka = 4.0 x 10-6
E. HBrO, Ka = 2.3 x 10-9
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