Titration Calculations

Molar Concentration

Molar concentration, also known as molarity, is the number of moles of solute per litre of solution.
It is measured in moles per litre (mol/L), or molar (M).
It can be calculated using the formula: Molarity = moles of solute / volume of solution in litres

Moles and Volume

The volume of solution required to neutralise the reactant can be measured using a burette during a titration. This value is used to calculate the number of moles.
The number of moles of the substance can be calculated using the formula: moles = molarity x volume
Remember that the volume must be in litres when using this formula to calculate moles.

Calculation in a Reaction

In a titration reaction, the balanced chemical equation can be used to derive the stoichiometric ratio of the reactants.
The stoichiometric ratio is the ratio of the moles of each reactant in the balanced equation.
The number of moles of one reactant can be used to determine the number of moles of another reactant or product using the stoichiometric ratio.
It’s essential to know the equivalent molarities of your reactants when doing a titration.

Calculating Molarity of Unknown Solution

The molarity of an unknown solution can be calculated using the titre volume, the molarity of the other reactant, and the stoichiometric ratio.
Use the formula: Molarity_unknown = (Molarity_known x Volume_known x Ratio_unknown) / (Volume_unknown x Ratio_known)
Care should be taken to match the volume measure (usually in cm³ or dm³) with the molarity (usually in mol/dm³).

(Remember to practice doing as many titration calculations as possible; this is the best way to familiarise yourself with the concept and application.)