IB Chemistry home > Syllabus 2016 > Acids and Bases > Buffers

Syllabus ref: 18.3

Buffers are solutions that resist change in pH on addition of small amounts of acid or base. They are very important in biological systems.


The buffer region on the pH curve represents the region where small additions of acid or base result in little or no change in pH.

The composition and action of a buffer solution.

Applications and skills

While the nature of the acid-base buffer always remains the same, buffer solutions can be prepared by either mixing a weak acid/base with a solution of a salt containing its conjugate, or by partial neutralization of a weak acid/basewith a strong acid/base.

In Chapter 8.6