Oxide and manganese 
 Name: oxide of manganese; the manganese sesquioxide information: Molecular formula: Mn2O3 CAS: nature: black crystals. Toxic! The relative density of 4.50. 
 Insoluble in water, acetic acid, insoluble in cold acid, dissolved in hot concentrated acid release chlorine Mn2O3 +6 of HCl == heat == 2MnCl2 + Cl2 ↑ +3 H2O, 
 Hot nitric acid and hot acid. 1080 ℃ deoxidation. Fine dust is combustible. Hydrogen reduction at 230 ° C to generate manganese tetroxide, generated more than 300 ℃ oxidation Asia manganese (MnO). 
 By manganese dioxide heated in air to 530 ~ 940 ° C system too. Trivalent manganese hydrous oxides called manganese brown, as cloth dyeing agent. System of manganese compounds, raw materials and intermediate products.