Titration calculator
This titration calculator finds how concentrated your sample is. Example: 24.6 mL of 0.1 mol/L NaOH neutralise 25 mL of hydrochloric acid, so c = 0.0984 mol/L.
Example: What should be calculated: Concentration of the sample (analyte) · Titrant concentration 0.1 mol/L · Titrant volume used 24.6 mL · Analyte volume 25 mL · Analyte coefficient ν(A) 1 · Titrant coefficient ν(T) 1 → Result: c(analyte) = 0.0984 mol/L. Source: Harris, Quantitative Chemical Analysis, Kap. „Titrations“ (n = c·V, Stoffmengenverhältnis am Äquivalenzpunkt). Updated: .
How it is calculated
In a titration a solution of unknown concentration (the analyte) is reacted with a standard solution of exactly known concentration (the titrant) up to the equivalence point. The volume used gives the unknown concentration.
Formula
At the equivalence point the amounts of substance are in the ratio of the reaction equation: n(A) / ν(A) = n(T) / ν(T), with n = c · V. Hence c(A) = c(T) · V(T) · ν(A) / (ν(T) · V(A)). To plan the titrant volume instead: V(T) = c(A) · V(A) · ν(T) / (ν(A) · c(T)). With volumes in mL and concentrations in mol/L, the product c·V is directly in millimoles.
Worked example
25 mL of hydrochloric acid is titrated with sodium hydroxide (c = 0.1 mol/L); 24.6 mL flow until the colour change. HCl and NaOH react 1 : 1, so n = 0.1 · 24.6 = 2.46 mmol and c(HCl) = 2.46 / 25 = 0.0984 mol/L. For sulfuric acid (H₂SO₄ + 2 NaOH, ν(A) = 1, ν(T) = 2) the same volume gives only 0.0492 mol/L. A sample of 0.1 mol/L and 25 mL needs exactly 25 mL of titrant at 1 : 1.
- The titrant concentration must be known exactly (primary standard or standardisation).
- Polyprotic acids or reactions with a different ratio need matching coefficients.
- Repeat the titration at least three times and average the volumes.
Frequently asked questions
What is the equivalence point?
The point at which analyte and titrant have reacted in exactly the ratio of the reaction equation. It is detected by an indicator colour change or a pH measurement.
How do I calculate concentration from the volume used?
With c(A) = c(T) · V(T) · ν(A) / (ν(T) · V(A)). For 24.6 mL of a 0.1 mol/L solution and a 25 mL sample (1 : 1) this gives 0.0984 mol/L.
What do the coefficients ν(A) and ν(T) mean?
The factors from the reaction equation. For H₂SO₄ + 2 NaOH, ν(A) = 1 and ν(T) = 2: twice as much NaOH is used as there is sulfuric acid.
Sources and legal basis
- Harris, Quantitative Chemical Analysis, Kap. „Titrations“ (n = c·V, Stoffmengenverhältnis am Äquivalenzpunkt)
- IUPAC Gold Book: equivalence point
As of: · Editorial policy
Related tools
- Molarity calculatorMolarity calculator: mol/L from mass and volume, the mass to weigh out for a solution, molarity from mass percent and density, and simple stoichiometry.
- pH calculator with step-by-step solutionCalculate the pH of strong and weak acids and bases – exact quadratic solution, pKa/pKb or Ka/Kb, and conversion between pH, pOH, [H₃O⁺] and [OH⁻].
- Dilution Calculator: C1V1 = C2V2, Dilution Ratios and MixingDilution calculator using C1V1 = C2V2: stock volume and diluent, final concentration, ratios like 1:50 (parts or total) and mixing two solutions.
- Molality CalculatorMolality calculator from the mass and molar mass of the solute, or from the amount of substance and the mass of the solvent, with mass fraction and the steps.
- Grams to Moles CalculatorGrams to moles calculator (and back) using molar mass: amount n = m / M, plus the number of particles via the Avogadro constant, with the steps and an example.
- Percent Yield CalculatorPercent yield calculator from actual and theoretical yield; the theoretical yield can be worked out from the limiting reagent and the balanced equation.
- Online CalculatorCalculator online, free and instant: type or tap and see the answer as you go – order of operations, brackets, percent, square root, steps and a history list.
- Cube calculatorCube calculator from edge length, face or space diagonal, volume or surface area: all measures at once, plus inscribed and circumscribed sphere and edge sum.
- Resistor Color Code Calculator: Read Bands or Find ColorsResistor color code calculator per IEC 60062: turn 3, 4, 5 or 6 color bands into ohms, tolerance and temperature coefficient – or find the bands for any value.