Manganese Oxide - Manganese

MnO, Mn ₃ O ₄ , Mn ₂ O ₃ , MnO ₂ and Mn ₂ O ₇ are known. MnO, which has a low oxidation state, is a basic oxide, Mn ₂ O ₇ , which has a high oxidation state, is an acidic oxide, and MnO ₂ and other intermediate oxides are amphoteric oxides. [ I ] Manganese oxide(II): MnO(70.94). Also called manganese monoxide. It occurs naturally as arginite. It is obtained by burning manganese carbonate in hydrogen or nitrogen, or by reducing manganese dioxide with hydrazine. Gray-green powder. Sodium chloride structure. Density 5.18 g cm ^-3 . Melting point 1650 °C. It is not easily reduced by hydrogen. It is a basic oxide that dissolves in hydrochloric acid, nitric acid, and sulfuric acid to give manganese(II) salt. It is used in catalysts, ceramics, dry batteries, mordants, and as a raw material for magnetic materials. [CAS 1344-43-0] [ II ] Manganese(III) _oxide : _Mn2O3 (157.87). Also known as manganese trioxide. It exists in two modifications, α and γ. The α form is obtained by heating _MnO2 in oxygen at 550-900 °C. It occurs naturally as braunite. It has black cubic crystals and a density of 4.81 g cm ^-3 . The γ form is obtained by heating MnO(OH) in a vacuum at 250 °C. It is a black tetragonal powder. It is an unstable form that changes to the α form when heated and does not revert to the γ form. When heated in air to over 940 °C, it releases _O2 and becomes _Mn3O4 . It is used in the glass industry and as _a colorant for ceramics. [CAS 1317-34-6] [ III ] Manganese(III) oxide Manganese(II): Mn ₃ O ₄ (228.81). Also called trimanganese tetroxide. Found naturally as hausmannite. Obtained by igniting metallic manganese or manganese compounds in air at 940°C or higher. Black crystals. Density 4.72 g cm ^-3 . Melting point 1564°C. Easily absorbs oxygen, and has a nonstoichiometric composition. Dissolves in concentrated hydrochloric acid, evolving chlorine to produce Mn ^II . Dissolves in hot concentrated sulfuric acid, evolving oxygen to produce Mn ^II . Used as an additive for steel. [CAS 1317-35-7] [ IV ] Manganese(IV) oxide: MnO ₂ (86.94). Also called manganese dioxide. [CAS 1313-13-9] [ Ⅴ ] Manganese oxide (Ⅶ): Mn ₂ O ₇ (221.87). Also called dimanganese heptaoxide. When potassium permanganate powder is added little by little to cold concentrated sulfuric acid to obtain a green solution, and cold water is added carefully, a dark brown oily liquid is obtained. Density 2.4 g cm ^-3 . When cooled with liquid air, it becomes dark green crystals. This is stable up to -5 °C, but at 0 °C it decomposes, releasing oxygen. At room temperature it decomposes explosively to MnO ₂ + O _2. It is a dangerous substance that will explode if it comes into contact with organic matter. [CAS 12057-92-0]

Source: Morikita Publishing "Chemical Dictionary (2nd Edition)" Information about the Chemical Dictionary 2nd Edition

MnO，Mn₃O₄，Mn₂O₃，MnO₂およびMn₂O₇などが知られている．酸化状態の低いMnOは塩基性酸化物，酸化状態の高いMn₂O₇は酸性酸化物で，中間のMnO₂などは両性酸化物である．【Ⅰ】酸化マンガン(Ⅱ)：MnO(70.94)．一酸化マンガンともいう．天然には緑マンガン鉱として産出する．炭酸マンガンを水素または窒素中で焼くか，二酸化マンガンをヒドラジンで還元すると得られる．灰緑色の粉末．塩化ナトリウム型構造．密度5.18 g cm^－3．融点1650 ℃．水素還元を受けにくい．塩基性酸化物で，塩酸，硝酸，硫酸などに溶けて，マンガン(Ⅱ)の塩を与える．触媒，陶磁器，乾電池，媒染剤，磁性材料の原料などに用いられる．[CAS 1344-43-0]【Ⅱ】酸化マンガン(Ⅲ)：Mn₂O₃(157.87)．三酸化二マンガンともいう．α形とγ形の2変態がある．α形はMnO₂を酸素中で550～900 ℃ に加熱すると得られる．天然にはブラウン鉱として産出する．黒色の立方晶系結晶．密度4.81 g cm^－3．γ形はMnO(OH)を真空中で250 ℃ に加熱して得られる．正方晶系の黒色の粉末．不安定型で加熱によりα形にかわりγ形に戻らない．空気中で940 ℃ 以上に加熱すると O₂ を放出してMn₃O₄となる．ガラス工業，窯業用着色剤などに用いられる．[CAS 1317-34-6]【Ⅲ】酸化二マンガン(Ⅲ)マンガン(Ⅱ)：Mn₃O₄(228.81)．四酸化三マンガンともいう．天然には，ハウスマン鉱として産出する．金属マンガンまたはマンガン化合物を空気中で940 ℃ 以上に強熱すると得られる．黒色の結晶．密度4.72 g cm^－3．融点1564 ℃．酸素を吸収しやすく，組成は非化学量論的である．濃塩酸に溶けて塩素を発生して Mn^Ⅱを生じる．熱濃硫酸には酸素を発生して溶け Mn^Ⅱとなる．鉄鋼添加剤に用いられる．[CAS 1317-35-7]【Ⅳ】酸化マンガン(Ⅳ)：MnO₂(86.94)．二酸化マンガンともいう．[CAS 1313-13-9]【Ⅴ】酸化マンガン(Ⅶ)：Mn₂O₇(221.87)．七酸化二マンガンともいう．冷濃硫酸に過マンガン酸カリウムの粉末を少量ずつ加えて得られる緑色溶液に，注意して冷水を加えると，暗褐色の油状液として得られる．密度2.4 g cm^－3．液体空気で冷やすと暗緑色の結晶となる．このものは－5 ℃ までは安定であるが，0 ℃ では酸素を発して分解する．常温では爆発的に分解し，MnO₂ ＋ O₂ となる．有機物に触れると爆発する危険物質である．[CAS 12057-92-0]

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