Iodometric titration of a Cu(II) solution. An interactive exercise.

Abstract

When a Cu(II) solution is treated with excess KI, Cu(II) is reduced to Cu(I) by iodide being this oxidized to iodine, I2. This redox reaction is simultaneous with a heterogenous reaction in which Cu(I) precipitates as white CuI. The released iodine is titrated to starch endpoint with thiosulfate and the required volume of titrant can be related to the amount of copper in the problem. The data are randomly generated and all stoichiometric factors must be correctly set up to solve the exercise. The statistical parameters are calculated for the obtained data.