Dimangantrioxid Chemische Eigenschaften,Einsatz,Produktion Methoden
R-S?tze Betriebsanweisung:
R36/37/38:Reizt die Augen, die Atmungsorgane und die Haut.
S-S?tze Betriebsanweisung:
S26:Bei Berührung mit den Augen sofort gründlich mit Wasser abspülen und Arzt konsultieren.
S36:DE: Bei der Arbeit geeignete Schutzkleidung tragen.
Chemische Eigenschaften
manganese(III) oxide is a black, lustrous powder, sometimes tinged brown. Very hard.decomposes at 1080℃. Soluble in cold hydrochloric acid; not soluble in nitric acid (decomposes), hot sulfuric acid; insoluble in water. Noncombustible.
manganese(III) oxide is obtained by igniting manganese(IV) oxide or a manganese(II) salt in air at 800°C. It reacts slowly with cold dilute acids to form manganese(III) salts. Manganese(III) oxide occurs in nature as braunite (3Mn2O3.MnSiO3 ) and the monohydrate (Mn2O 3.H2O) occurs in the mineral manganite. The manganese(III) oxide crystal lattice contains Mn3+ and O2– ions. With concentrated alkalis, it undergoes disproportionation to give manganese(II) and manganese(IV) ions.
Verwenden
Manganese(III) oxide is used to produce ceramic magnets and semiconductors. Further, it serves as a precursor to lithium manganese oxide. In addition to this, it acts as a useful battery cathode.
synthetische
Anhydrous manganese(III) oxide is found as the mineral braunite, Mn2O3, while a hydrated form, Mn2O3.H2O, which is chemically more reactive, occurs as manganite. Manganese forms both anions and cations in oxidation state +3. Simple salts of tervalent manganese are not stable. However, complexes are more stable, the hexacyanomanganates(III) being an example: K3Mn(CN)6 is a red crystalline solid, isomorphous with potassium hexacyanoferrate(III) and slowly hydrolysed.
Manganese(III) oxide is formed as a grey solid by heating manganese(IV) oxide to 700°C for several hours:
4MnO2 ---> 2Mn203 + O2
It is converted into trimanganese tetroxide when heated above 940°C in air or reduced by hydrogen above 230°C. Hot concentrated hydrochloric acid is oxidized to chlorine by manganese(III) oxide:
Mn203 (s) + 6H + + 2e- ==2Mn2+ + 3H2O
Mn203 (s) + 6H + + 2Cl- ---> 2Mn2+ + 3H2O + Cl2
Definition
In nature as manganite,
a manganese ore.
Hazard
Flammable in finely divided form. Toxic by
inhalation of dust.
Sicherheitsprofil
Moderately toxic by
subcutaneous and intratracheal routes. See
also MANGANESE COMPOUNDS.
Dimangantrioxid Upstream-Materialien And Downstream Produkte
Upstream-Materialien
Downstream Produkte
