Henderson-Hasselbalch equation

The Henderson and Hasselbalch equation describes the relationship between buffer composition and its acidity. Under simplifying assumptions:

$$\mathrm{pH} = \mathrm{p}K_A + \log \frac{c_{\mathrm{B}}}{c_\mathrm{A}}$$,

where
 * pH is the resulting pH of the buffer,
 * pKA is the dissociation constant of the conjugate acid of the buffer,
 * cA and cB are the equilibrium concentrations of the conjugate acid and base forming the buffer.

Related articles

 * Derivation of the Henderson-Hasselbalch equation and other details.