Back Titration or Indirect Titration Tutorial
Key ConceptsA back titration, or indirect titration, is generally a two-stage analytical technique:
- Reactant A of unknown concentration is reacted with excess reactant B of known concentration.
- A direct titration is then performed to determine the amount of reactant B in excess.
Back titrations are used when:
- one of the reactants is volatile, for example ammonia.
- an acid or a base is an insoluble salt, for example calcium carbonate
- a particular reaction is too slow
- direct titration would involve a weak acid - weak base titration
(the end-point of this type of direct titration is very difficult to observe)