Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Potassium manganate is the chemical compound with the formula K2MnO4. This purple salt is an intermediate in the industrial synthesis of potassium permanganate, KMnO4, a common chemical. Occasionally, potassium manganate and potassium permanganate are confused, but they are different compounds with distinctly different properties. The conversion is signaled by the color change from purple, characteristic of permanganate, to the green color of manganate. This reaction also illustrates the fact that manganate(VII) can serve as an electron acceptor in addition to its usual role as an oxygen-transfer reagent. Barium manganate, BaMnO4, is generated by the reduction of KMnO4 with iodide in the presence of barium chloride. Just like BaSO4, BaMnO4 exhibits low solubility in virtually all solvents.