The oxidation-reduction titrations are used in this titration. When sulfuric acid is used to titrate ferrous ammonium sulfate solution against potassium permanganate in the presence of an acidic media. To avoid manganese oxide precipitation, an acidic media is required. The self-indicator KMnO4 is used in this titration, which is known as permanganate titration.
Learn About Organic Chemistry with Mohr’s Salt Titration Experiment