Buffer capacity will predominately depend on: Select the correct answer below: a. the strength of the acid or base being added b. the strength of the acid and base in the buffer c. the concentration of acid or base being added d. the concentration of the buffer solution

(d) The concentration of buffer solution

Explanation:

Buffer capacity is a measure of the efficiency of a buffer in resisting changes in pH. Conventionally, the buffer capacity (β) is expressed as the amount of strong acid or base, in gram-equivalents, that must be added to 1 liter of the solution to change its pH by one unit.

In practice, smaller pH changes are measured and the buffer capacity is quantitatively expressed as the ratio of acid or base added to the change in pH produced (e.g., mEq./pH for x volume). The buffer capacity depends essentially on 2 factors:

(1) Ratio of the salt to the acid or base. The buffer capacity is optimal when the ratio is 1 : 1; that is, when pH = pKa

(2) Total buffer concentration. For example, it will take more acid or base to deplete a 0.5 M buffer than a 0.05 M buffer