It is a redox titration that involves the use of permanganates to measure the amount of analyte present in unknown chemical samples.
The titration involves volumetric manipulations to prepare the analyte solutions.
Depending on the conditions in which the titration is performed, the manganese is reduced from an oxidation of +7 to +2, +4, or +6.
In most cases, permanganometry is performed in a very acidic solution in which the following electrochemical reaction occurs:[3] which shows that KMnO4 (in an acidic medium) is a very strong oxidizing agent, able to oxidize Fe2+ (E°Fe3+/Fe2+ = +0.77 V), Sn2+ (E°Sn4+/Sn2+ = +0.2 V), and even Cl− (E°Cl2/Cl− = +1.36 V).
Instead, it accepts only 3 electrons and forms solid MnO2 by the following reaction: In a strongly basic solution, with the concentration c(NaOH) >1 mol dm−3, only one electron is accepted to produce manganate: