Henderson-Hasselbalch Buffer

Conjugate-base / acid ratio and moles for a target pH. Bundled pKa for common laboratory buffers.

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Formula and source

pH = pKa + log10([A-] / [HA]). ratio = 10^(pH - pKa). fraction_base = ratio / (ratio + 1). Moles each side from total buffer concentration * total volume * fraction.

Henderson-Hasselbalch equation. First principles. Common laboratory buffer pKa values bundled in BUFFER_PKA (data/lab/buffer-pka.json) with per-entry citation (Good et al. 1966; CRC Handbook 95th ed.).

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