Titration Calculations

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.)