Acid-Base Titration Calculator

Titration is a lab technique where a solution of known concentration is added to another solution to determine its acidity or basicity — the Acid-Base Titration Calculator calculates the pH at any point in that process. Select your titration type (strong or weak acid/base combinations), then enter the analyte concentration, analyte volume, titrant concentration, and volume of titrant added — plus Ka or Kb for weak acid/base titrations. You'll get the pH, pOH, [H⁺] and [OH⁻] concentrations, equivalence volume, and current titration region.

M
mL
M
mL

Required for weak acid titrations

Required for weak base titrations

Results

pH

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pOH

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[H⁺] Concentration

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[OH⁻] Concentration

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Equivalence Volume

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Titration Region

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Results Table

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Frequently Asked Questions

What is a titration and how does it work?

Titration is a quantitative analytical technique used to determine the concentration of an unknown solution by reacting it with a solution of known concentration (titrant) until the equivalence point is reached, indicated by a color change or pH measurement.

What is the equivalence point in a titration?

The equivalence point is the stage in a titration where the moles of acid equal the moles of base (nH⁺ = nOH⁻). At this point, all the analyte has been neutralized by the titrant, and the pH depends on the nature of the salt formed.

How do you calculate pH during different stages of titration?

The pH calculation depends on the titration region: before equivalence (excess analyte), at equivalence (hydrolysis of salt), or after equivalence (excess titrant). For weak acid/base systems, the Henderson-Hasselbalch equation is used in buffer regions.

What is the difference between strong and weak acid-base titrations?

Strong acid-strong base titrations have a sharp equivalence point at pH 7. Weak acid-strong base titrations have equivalence points above pH 7, while weak base-strong acid titrations have equivalence points below pH 7.

When do you use the Henderson-Hasselbalch equation in titrations?

The Henderson-Hasselbalch equation (pH = pKa + log([A⁻]/[HA])) is used in buffer regions of weak acid-strong base titrations, where both the weak acid and its conjugate base are present in significant amounts.

How do you determine the concentration of an unknown acid using titration?

Use the formula nH⁺·Ma·Va = nOH⁻·Mb·Vb, where n is the number of H⁺ or OH⁻ ions, M is molarity, and V is volume. Knowing the titrant concentration and volume at equivalence point allows calculation of the unknown concentration.

What happens at the equivalence point of a weak acid-strong base titration?

At the equivalence point, all weak acid is converted to its conjugate base, which undergoes hydrolysis to produce OH⁻ ions, making the solution basic (pH > 7). The pH can be calculated using [OH⁻] ≈ √(Kb·C), where Kb = Kw/Ka.