Find the Concentration

The everyday use of a titration: how strong is this vinegar, this cleaning product or this acid? From the sample volume, the titrant concentration and the burette readings at the end point — averaged over repeat titrations.

Acid-BaseTitrationLab

Inputs

Input examples

The ratio says how many moles of titrant react with one mole of the substance in the sample. Enter one end-point volume, or the results of several titrations separated by commas: the calculator averages them and shows how well they agree. The molar mass is optional, to get the concentration in g/L.

Sample volume

Titrant concentration

End-point volumes — in mL, one or more

Molar mass of the substance — optional, g/mol

Dilution factor — if the sample was diluted first (1 = not)

From Burette Reading to Concentration

At the end point the moles of titrant you added match the moles of the substance in the sample, multiplied by the reaction ratio. Moles of titrant are concentration × volume, so the unknown concentration follows by dividing by the sample volume.

A single titration can be off by a drop. That is why titrations are repeated until results agree within about 0.1 mL; the average is then much more reliable. If the sample was diluted before titrating, multiply back by the dilution factor.

n= C × V

repeatuntil within 0.1 mL

g/L= mol/L × M

diluted?× the factor

Your Titrations

results

concentration from each titration

average

average ± one standard deviation

Result

Enter the values above

Each Titration

your readings

Titration	End point	Concentration	From average

Worked Techniques

Strength of Vinegar

Acetic acid reacts 1 : 1 with sodium hydroxide. Times the molar mass of 60.05 g/mol that is about 50 g/L, roughly 5% acid.

Example: 0.83 × 60.05 = 49.8 g/L.

A Diprotic Acid

Each sulfuric acid molecule gives two H⁺, so it takes two NaOH: divide by 2.

Example: 25 mL, 20.0 mL of 0.1 M NaOH: 0.04 M.

Diluted Samples

Strong products are often diluted ten times first so the burette reading stays reasonable.

Example: diluted 10×, measured 0.083 M: the original is 0.83 M.

Sources & Verification

References

S. S. Zumdahl & S. A. Zumdahl, Chemistry, 10th ed., Cengage, 2018 — Ch. 4 (Types of Chemical Reactions and Solution Stoichiometry) and Ch. 15 (Acid–Base Equilibria).