ABSTRACT
What is the defi nition of a buffer? An acid-base buffer solution resists a change of pH when an acid or base is added to it. It consists of a weak acid and its conjugate base (salt).
The general equation for a buffer system is:
HA (undissociated acid) ⇋ H+ (hydrogen ion) + A-(conjugate base)
If H+ ions are added to the solution, the equilibrium shifts to the left, and the H+ are ‘neutralised’ by the conjugate base, minimising an increase in free [H+] and maintaining a constant pH.
