If a phosphate buffer (pK = 6.82) was formulated such that its pH was 7.3, it would be best suited to buffer against _____. If instead, it was formulated such that its pH was 6.3, it would be best suited to buffer against _____.

Question

Quizplus · Accepted Answer

Buffers are most effective when the pH is close to the pKa of the buffering agent. A buffer with a pH above its pKa (7.3 vs. 6.82) is best suited to buffer against added acid, as it can donate protons. Conversely, a buffer with a pH below its pKa (6.3 vs. 6.82) is better at buffering against added base, as it can accept protons.

If a Phosphate Buffer (PK = 6