Explain what determines the buffering capacity of a buffer solution.

Let's break down the information about buffer capacity:

A buffer pair has its maximum buffering capacity when:

1. pH is equal to pK: This occurs when the concentration of the weak acid is equal to the concentration of its conjugate base ($[HA] = [A^-]$). At this point, the buffer can neutralize added acid or base most effectively, as it has equal amounts of both components to react with.
2. Within a pH interval of $\pm$1 unit of its pK: A buffer is generally considered effective within a pH range that is approximately one pH unit above and one pH unit below its pK value. Outside this range, the ratio of acid to base becomes too extreme, and the buffer's ability to resist pH changes significantly decreases.
3. When the ratio of acid to base is 1:10 or 10:1: This describes the limits of a buffer's effective range, not its maximum capacity. While a buffer still functions within these ratios, its buffering capacity is significantly reduced compared to when the ratio is 1:1. Beyond these ratios, the buffer is largely ineffective.

Regarding the statement:

• The larger the pK value, the smaller the extent of dissociation: The pK value ($pK_a$) is a measure of an acid's strength. A larger $pK_a$ means a smaller acid dissociation constant ($K_a$). A smaller $K_a$ indicates that the acid is weaker and therefore dissociates to a lesser extent in solution, meaning fewer hydrogen ions are released.