A buffer has the highest capacity when the
concentrations of HA and A- are equal.
For a given addition of acid or base, the concentration ratio ([A-]/[HA]) changes less for similar buffer component concentrations than it does for different concentrations.
Key Concepts
Buffer range: the pH range over which the buffer acts effectively;
defined as pKa +/- 1 pH unit
A buffer whose pH is equal to or near the pKa of its acid
component has the highest buffer capacity.
| Previous slide | Next slide | Back to first slide | View graphic version |