Estimation of oxidising substance involving the liberation of iodine, and subsequent volumetric estimation of I2 are referred to as2Cu2++4I⊖⟶Cu2I2+I2I2+S2O32−⟶S4O62−+2I⊖

Iodometry involves indirect titration of iodine liberated by reaction with the analyte, whereas iodimetry involves direct titration using iodine as the titrant. The iodometric titration is a general method to determine the concentration of an oxidising agent in solution.