Final answer:
True, a buffer's capacity to neutralize added acid is indeed dependent on the amount of weak acid it contains since higher concentrations of weak acid and its conjugate base provide greater buffer capacity.
Step-by-step explanation:
The statement that a buffer's capacity to neutralize added acid depends on the number of moles of weak acid the buffer contains is true.
Buffer capacity is defined as the amount of acid or base that can be added to a buffer solution before the pH changes significantly.
This capacity is directly related to the concentrations of the weak acid and its conjugate base present in the solution.
A higher concentration of these components means the buffer can neutralize more added acid or base without a large change in pH.
Hence, buffers with more moles of weak acid and its conjugate base have larger capacities and are more resistant to pH changes upon addition of strong acids or bases.