Manganese dioxide

The oxide of manganese (IV) MnO₂ is chemical compound such a known like dioxide of manganese . It is of color black or brown. One naturally finds it in the Pyrolusite which is the metal independent source of Manganèse. It is also present in the manganese nodules. The principal applications of MnO₂ are the dry cells like the alkaline piles and the piles Zn-Cd. In 1976, this application corresponded to a consumption of a half-million annual tons of pyrolusite. It is also used in the production of Permanganate S like KMnO₄. It is largely used as oxidant in organic chemistry, for example, for the oxidation of the allyl alcohols A gray substance, the Manganate of potassium, is obtained after a 10 minutes fusion of manganese oxide with an alkaline salt and adding oxidising agents like the Salpêtre (nitrate of potassium: KNO_{3) or of the Perchlorate of potassium (KClO₄). The potassium manganate can be purified by flash distillation to give crystals dark green (prism S Orthorhombique S) the manganate of potassium is soluble only in the Alcali S; under the not-alkaline conditions it dismute in Permanganate of potassium and manganese oxide (IV) (MnO2).}

The potassium manganate is converted into potassium permanganate in acid aqueous solution:

3MnO₄^2- + 4:00 ⁺ - > 2MnO₄^- + MnO₂ (S) + 2:00 ₂O

MnO₄^-a a color crimson.

MnO₄^2- has a green color.

MnO₂ is used as catalyst at the laboratory for the preparation of oxygen starting from potassium chlorate; it is one of the traditional experiments in the basic teaching of chemistry. The manganese dioxide catalyzes also the decomposition of hydrogen peroxide.
2:00 ₂O₂ (aq) - > O₂ (G) + 2:00 ₂O (L)

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