# How do buffers regulate the pH of a fluid?

Aug 24, 2017

How do buffers regulate the $p H$ of a solution......?

#### Explanation:

See this older answer.

The basic equation, derived in the link, is.....

$p H = p {K}_{a} + {\log}_{10} \left\{\frac{\left[{A}^{-}\right]}{\left[H A\right]}\right\}$

And thus, a buffer, which is composed of a weak acid, and its conjugate base in appreciable concentration, maintains a $p H$ tolerably close to the $p {K}_{a}$ of the parent acid. Addition of acid simply protonates the base, addition of base simply deprotonates the parent acid.

And we can actually choose a starting $p H$ by mixing acid and base appropriately.