The buffer capacity of a solution may be defined as the number of moles of H+ that will change the pH of 1.00 L of the buffer by 1.00 pH units. What is the buffer capacity of a solution which is 0.10 M in acetic acid (Ka = 1.8 × 10^-5) and 0.30 M in sodium acetate, in units of mol (H+) per liter? A) 0.20 B) 0.10 C) 0.087 D) 0.009 E) zero

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Quizplus · Accepted Answer

The buffer capacity is determined by the concentration of the weak acid and its conjugate base. In this case, the buffer capacity is approximately the sum of the concentrations of acetic acid and acetate, which is 0.10 M + 0.30 M = 0.40 M. However, since the problem asks for the number of moles of H+ that will change the pH by 1 unit, we consider the limiting reagent, which is the acetic acid, giving a buffer capacity of 0.20 mol/L.

The Buffer Capacity of a Solution May Be Defined as the Number