Blood, oceans, and cells all rely on buffers to hold pH steady. See how a weak-acid buffer shrugs off added acid that would wreck pure water.
Buffer Solution (Henderson–Hasselbalch)Live
resisting pH change
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A buffer is a weak acid plus its conjugate base. Its pH follows Henderson–Hasselbalch, pH = pKa + log([base]/[acid]). Add strong acid and the buffer neutralizes most of it, so the pH barely moves — unlike pure water. Educational tool.
Reading this result: Base and acid are near equimolar (ratio 1), so pH sits right at pKa where buffering capacity peaks — the added acid moves it only 2.2 pH units instead of crashing the solution.
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How it works
A buffer pairs a weak acid with its conjugate base, giving pH = pKa + log([base]/[acid]) (Henderson–Hasselbalch). When strong acid is added, the base component neutralizes it, so the pH barely shifts — the resistance that keeps biological systems alive. Educational tool.
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Is this henderson hasselbalch calculator tool really free?▾
Yes. Buffer Solution runs entirely in your browser using your device's own compute, so local use is free forever. You only pay Compute Tokens if you scale a job to the cloud.
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No. Everything runs client-side in a modern browser — no downloads, no license, no account required to start.
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The solver uses established numerical methods, but results are for research and educational purposes and should be validated against experiment or professional review before you rely on them.