Question

How do chemical buffer systems resist changes in pH?

Answer 1

See this old answer.

Explanation:

A buffer consists of a weak acid and its conjugate base mixed together in APPRECIABLE concentrations. Added `H_3O^+` or `HO^-` tends to be sopped up by the acid or base already in solution, and `pH` change is only marginal. In the absence of a buffer, `pH` might change from 3-4 units.