Final answer:
The buffer capacity is influenced by the concentrations of the weak acid and its conjugate base in the solution; higher concentrations yield greater buffer capacities.
Step-by-step explanation:
To calculate the buffer capacity of a solution, we consider the amount of acid or base that can be added to it before there is a significant change in pH, typically by one unit. This capacity relies heavily on the concentration of the weak acid and its conjugate base in the solution. Higher concentrations of these components result in a greater buffer capacity because the buffer can neutralize more added acid or base without a large change in pH.
For example, a buffer solution containing 1.0 M acetic acid and 1.0 M sodium acetate will have a higher buffer capacity compared to a buffer solution that has 0.10 M acetic acid and 0.10 M sodium acetate. This is because the first solution has more molecules of weak acid and conjugate base present to absorb the added H+ or OH- ions without a significant pH change.