Online Tool Store
Titration Curve Simulator
Enter the acid/base concentrations and volumes to plot a simulated pH titration curve, including the approximate equivalence point.
🔒 This tool runs entirely in your browser. Your files are never uploaded to a server.
Equivalence volume
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Approx. pH at equivalence
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How Titration Curve Simulator works
- Choose strong or weak acid, set its concentration and volume, and set the strong base (NaOH) concentration used to titrate it — a weak acetic-acid sample is pre-filled.
- The equivalence volume is calculated from stoichiometry:
V(base) = (C(acid) × V(acid)) ÷ C(base), the point where moles of base added equal moles of acid present. - For a strong acid, pH before equivalence comes from the leftover H⁺ concentration, and after equivalence from the excess OH⁻ concentration — a direct charge-balance calculation.
- For a weak acid, pH before equivalence uses the Henderson-Hasselbalch equation from the conjugate acid/base ratio, and pH at/after equivalence accounts for the conjugate base's hydrolysis.
The steep jump in the curve near the equivalence volume — the "vertical" section — is what makes titration useful for finding an unknown concentration: a small volume change there causes a large pH swing, which is what an indicator or pH meter is detecting at the endpoint.
FAQ
Why does a weak acid + strong base curve reach equivalence above pH 7?
At equivalence, all that remains in solution is the acid's conjugate base — for acetic acid, acetate ion — which hydrolyses water and makes the solution mildly basic. A strong acid's conjugate base does not do this, which is why that curve's equivalence point sits at exactly pH 7.
What does the pKa field control?
pKa (the negative log of the acid dissociation constant, Ka) sets how strongly the acid resists pH change and where the buffering plateau sits — at half the equivalence volume, pH equals pKa exactly, a landmark used to identify an unknown acid experimentally.
How accurate is the weak-acid curve compared to a lab measurement?
It uses the standard introductory-chemistry approximations — Henderson-Hasselbalch before equivalence, and a simplified conjugate-base hydrolysis estimate at and after equivalence — which match real titration curves closely away from the very start and very end, but are not a full equilibrium solver, so treat exact values near the extremes as approximate.
How we compare
| Feature | Online Tool Store | Doing it manually | A generic online tool |
|---|---|---|---|
| No file upload — runs in your browser | ✓ | N/A | ✗ |
| No sign-up required | ✓ | ✓ | ✗ |
| Free, no watermark | ✓ | ✓ | ✗ |
Dedicated titration software is built for research labs, with a learning curve to match. This tool covers the standard general-chemistry case — strong or weak acid against a strong base — with a chart and equivalence point you can read in seconds.