Titration Calculator

Table of contents

• How to use
• Common mistakes
• Definitions
• Methodology
• Limitations & assumptions
• Sources

Analyte: The substance being measured, usually in the flask.

Titrant: A solution of known concentration added to react with the analyte.

Molarity (M): Concentration measured in moles of solute per liter of solution.

Equivalence point: The ideal point where analyte and titrant react in the exact mole relationship set by the balanced equation.

Endpoint: The observed signal, often an indicator color change, used to estimate the equivalence point.

Aliquot: The measured portion of analyte solution used for one titration.

Millimole (mmol): One thousandth of a mole. Multiplying M by mL gives mmol.

Reaction parts: The whole-number coefficients in a balanced chemical equation. They set the mole relationship between analyte and titrant. [1]

Mistake: Using a 1:1 relationship when the balanced equation has unequal reaction parts.
Fix: Enter the analyte and titrant coefficients from the balanced equation in Advanced options.

Mistake: Entering a final burette reading as the titrant volume delivered.
Fix: Enter final reading minus initial reading, unless the initial reading was 0.00 mL.

Mistake: Typing liters into a field labeled mL.
Fix: Convert to mL before entry. For example, 0.025 L is 25 mL.

Mistake: Mixing up analyte and titrant reaction parts.
Fix: Match each coefficient to the substance's role in the balanced equation, not its position on the page.

Mistake: Treating the observed endpoint as the exact equivalence point.
Fix: Use the measured endpoint volume for the calculation and report measurement uncertainty or indicator error when your lab requires it.

• The calculation applies to ideal equivalence-point stoichiometry, not pH before or after equivalence.
• You need a balanced reaction and positive whole-number reaction parts.
• Enter volumes in mL and concentrations in M; the calculator does not convert liters entered in an mL field.
• A measured endpoint can differ from the true equivalence point because of indicator choice, burette reading precision, technique, or incomplete reaction.
• This calculator does not calculate pH, buffer behavior, weak-acid or weak-base equilibrium, or uncertainty propagation.

Calculation method

The calculator finds the titrant amount from its concentration and delivered volume. Using M and mL gives mmol directly, so no separate liter conversion is needed.

titrant amount (mmol) = titrant concentration (M) x titrant volume (mL)

It then uses the whole-number parts from the balanced reaction. For example, if 1 analyte part reacts with 2 titrant parts, the analyte amount is half the titrant amount.

analyte amount (mmol) = titrant amount x analyte parts / titrant parts

The calculator rearranges this relationship to solve for the selected concentration or volume. The balanced-reaction parts determine the required mole relationship. [1]

analyte concentration (M) = titrant concentration x titrant volume x analyte parts / (titrant parts x analyte volume)

titrant volume (mL) = analyte concentration x analyte volume x titrant parts / (titrant concentration x analyte parts)

analyte volume (mL) = titrant concentration x titrant volume x analyte parts / (titrant parts x analyte concentration)

titrant concentration (M) = analyte concentration x analyte volume x titrant parts / (analyte parts x titrant volume)

Worked example

Suppose 25.00 mL of 0.100 M titrant reacts with 20.00 mL of analyte. The balanced reaction has 1 analyte part and 2 titrant parts. The titrant amount is 0.100 x 25.00 = 2.50 mmol. The analyte amount is 2.50 x 1 / 2 = 1.25 mmol. The analyte concentration is 1.25 / 20.00 = 0.0625 M.

Calculation details

Known concentrations and volumes must be greater than zero. Each reaction part must be a whole number of 1 or more. The decimal-place setting changes only the displayed rounding; calculations use the unrounded value.