Question

What is a buffer in chemistry?

Answer 1

A buffer solution is defined as a a solution that resist the change on its pH.

Explanation:

A buffer solution is defined as a a solution that resist the change on its pH.

It is usually prepared from a weak acid and the salt of its conjugate base or a weak base and the salt of its conjugate acid.

An example of a buffer solution is a solution made from acetic acid `CH_3COOH` and sodium acetate `NaCH_3COO`.

Note that, when an acid is added to the solution, it will react with `NaCH_3COO`, however, if a base is added to the solution it will react with `CH_3COOH`. In both cases, the change on the pH will be very small.

Here is a video that fully explains this topic:
Acid - Base Equilibria | Buffer Solution.