Question

How is KMnO4 prepared from pyrolusite ore?

Answer 1

Pottassium Permanganate (KMnO4) is prepared fromPyrolusite ore (MnO2). The finely powdered Pyrolusite ore(MnO2) is fused with an alkali metal hydroxide like KOH in the presence of air or an oxidizing agent like KNO3 to give the dark green potassium Manganate (K2MnO4). Potassium manganate disproportionate in a neutral or acidic solution to give potassium permanganate.



2 MnO2 + 4 KOH + O2 ----------> 2K2MnO4 + 2H2O


3 MnO42- + 4H+ ------------> 2MnO4- + MnO2 + 2H2O


Commercially potassium permanganate is prepared by the alkaline oxidative fusion of Pyrolusite ore (MnO2) followed bythe electrolytic oxidation of manganate (4) ion.



2 MnO2 + 4KOH + O2 -----------> 2K2MnO4 + 2H2O


MnO42- ------(electrolytic oxidation)----> MnO4- + e-

Answer 2

Preparation of Potassium permanganate (KMnO4)Pottassium Permanganate(KMnO4) is prepared fromPyrolusite ore(MnO2). The finely powderedPyrolusite ore(MnO2)is fused with an alkali metal hydroxide like KOH in the presence of air oran oxidizing agent like KNO3to give the dark greenpotassium Manganate(K2MnO4). Potassium manganate disproportionate in a neutral or acidic solution to givepotassium permanganate.2 MnO2+ 4 KOH + O2----------> 2K2MnO4+ 2H2O3 MnO42-+ 4H+------------> 2MnO4-+ MnO2+ 2H2OCommerciallypotassium permanganate is preparedby the alkaline oxidative fusion ofPyrolusite ore(MnO2)followed bythe electrolyticoxidation of manganate (4) ion.2 MnO2+ 4KOH + O2-----------> 2K2MnO4+ 2H2OMnO42-------(electrolytic oxidation)----> MnO4-+ e-