The pK_a of lactic acid is 3.86. What is the pH of a buffer in which the lactic acid concentration is 0.20 M and the sodium lactate concentration is 2.0 M? A) 2.86 B) 3.86 C) 4.86 D) 7.00

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Quizplus · Accepted Answer

The pH of the buffer can be calculated using the Henderson-Hasselbalch equation: pH = pKa + log([A-]/[HA]), where [A-] is the concentration of the conjugate base (sodium lactate, 2.0 M) and [HA] is the concentration of the acid (lactic acid, 0.20 M). Substituting the given values: pH = 3.86 + log(2.0/0.20) = 3.86 + 1 = 4.86.

The PKa of Lactic Acid Is 3

The PK_a of Lactic Acid Is 3