# What is the Henderson-Hasselbalch equation?

Apr 17, 2014

The Henderson-Hasselbalch equation is an equation that determines the pH pf a buffer.

Acid Buffers

For a solution of a weak acid and its conjugate base,

HA + H₂O ⇌ H₃O⁺ + A⁻

pH = $p {K}_{a} + \log \left(\text{[A⁻]"/"[HA]}\right)$

Base Buffers

For a solution of a weak base and its conjugate acid,

B+ H₂O ⇌ BH⁺ + OH⁻

pOH = $p {K}_{b} + \log \left(\text{[BH⁺]"/"[B]}\right)$