Ions are formed when inonic compounds dissociate in an aqueous medium. They grant solutions the ability to conduct electricity. The electrical conductivity of a solution increases with greater ion concentration or with solutions of ions that have a greater charge. The electrical conductivity of a solution is reduced when an ion is removed from a combined solution duirng a chemical reaction to form a gas or precipitate. When the ions of one of the reactants in a chemical reation is in excess, a greater conductivity will result. But when two solutions are combined in a ratio that has an equal amount of reactants, the maximum number of ions will be removed, and a low conductivity will result.
To use conductivity to determine stoichiometric coefficients in a chemical reaction.