Calculator Inputs
Example Data Table
| Titration Type | Analyte Conc. (M) | Analyte Vol. (mL) | Titrant Conc. (M) | pKa | Target Vol. (mL) |
|---|---|---|---|---|---|
| Weak acid with strong base | 0.100 | 25.0 | 0.100 | 4.76 | 12.5 |
| Strong acid with strong base | 0.150 | 20.0 | 0.100 | Not needed | 15.0 |
| Strong base with strong acid | 0.100 | 30.0 | 0.120 | Not needed | 20.0 |
Formula Used
Equivalence volume: Veq = (Canalyte × Vanalyte) ÷ Ctitrant
Strong acid before equivalence: pH = −log10((nacid − nbase) ÷ Vtotal)
Strong base before equivalence: pOH = −log10((nbase − nacid) ÷ Vtotal), then pH = 14 − pOH
Weak acid buffer region: pH = pKa + log10(nA− ÷ nHA)
Weak acid at equivalence: Kb = Kw ÷ Ka, then [OH−] ≈ √(Kb × Csalt)
These equations estimate the curve across initial, buffer, equivalence, and excess titrant regions. Results are idealized and assume complete mixing and standard aqueous behavior.
How to Use This Calculator
- Select the titration system that matches your experiment.
- Enter analyte concentration and starting volume.
- Enter titrant concentration and pKa when needed.
- Choose the target titrant volume for a specific pH reading.
- Set the number of curve points to control graph detail.
- Press Calculate Curve to show the result block above the form.
- Review the chart, equivalence point, and data table.
- Export the generated curve data to CSV or PDF.
FAQs
1. What does this titration curve calculator show?
It estimates pH across added titrant volumes, highlights equivalence behavior, and creates a curve table for quick study, lab planning, and comparison.
2. Which titration types are supported?
It supports strong acid with strong base, weak acid with strong base, and strong base with strong acid cases.
3. Why is pKa needed for weak acid titration?
pKa controls buffer behavior and half-equivalence pH. Without it, the calculator cannot estimate the weak acid curve correctly.
4. Does the calculator replace laboratory measurement?
No. It gives theoretical estimates under ideal conditions. Real samples may shift because of temperature, ionic strength, impurities, or instrument error.
5. What is the equivalence volume?
It is the titrant volume where stoichiometric moles of acid and base are equal. The curve changes steeply near this point.
6. Why does the weak acid curve show a buffer region?
Before equivalence, both weak acid and conjugate base coexist. That mixture resists pH change and follows the Henderson–Hasselbalch relationship.
7. Can I export the generated results?
Yes. Use the CSV button for raw data and the PDF button for a simple summary report with key calculated values.
8. Why does equivalence pH differ from 7 sometimes?
Strong acid and strong base systems often center near 7. Weak acid systems produce a basic equivalence point because conjugate base hydrolysis matters.