# How does a buffer work in chemistry?

$p H = p {K}_{a} + {\log}_{10} \left\{\frac{\left[{A}^{-}\right]}{\left[H A\right]}\right\}$
Clearly, we can take a weak acid $\left[H A\right]$, add half an equiv of strong base, and we a buffer solution, whose $p H = p {K}_{a}$.