The story
Named after Lawrence Joseph Henderson, who devised a related equation in 1908, and Karl Albert Hasselbalch, who re-expressed it in logarithmic terms.
Etymology from Wiktionary, CC BY-SA 4.0.
Henderson-Hasselbalch equation
Today it means: An equation describing the derivation of pH as a measure of acidity (using pKa, the negative log of the acid dissociation constant) in biological and chemical systems. Full definition →