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Curium(III) oxide is a compound composed of curium and oxygen with the chemical formula Cm 2 O 3. It is a crystalline solid with a unit cell that contains two curium atoms and three oxygen atoms. The simplest synthesis equation involves the reaction of curium(III) metal with O 2−: 2 Cm 3+ + 3 O 2−---> Cm 2 O 3. [1]
Curium readily reacts with oxygen forming mostly Cm 2 O 3 and CmO 2 oxides, [1] but the divalent oxide CmO is also known. [2] Black CmO 2 can be obtained by burning curium oxalate (Cm 2 (C 2 O 4) 3), nitrate (Cm(NO 3) 3), or hydroxide in pure oxygen. [3] [4] Upon heating to 600–650 °C in vacuum (about 0.01 Pa), it transforms into the whitish ...
Metallic curium is annealed in air or in an oxygen atmosphere: [1] Cm + O 2 → CmO 2. Curium(III) hydroxide and curium(III) oxalate are also usually used for this purpose: Cm(OH) 4 → CmO 2 + 2H 2 O Cm(C 2 O 4) 2 → CmO 2 + 2CO 2 + 2CO. Another way is the reaction of curium(III) oxide in an oxygen atmosphere at 650 °C: [2] 2Cm 2 O 3 + O 2 ...
Curium readily reacts with oxygen forming mostly Cm 2 O 3 and CmO 2 oxides, [53] but the divalent oxide CmO is also known. [67] Black CmO 2 can be obtained by burning curium oxalate (Cm 2 (C 2 O 4) 3), nitrate (Cm(NO 3) 3), or hydroxide in pure oxygen. [29] [68] Upon heating to 600–650 °C in vacuum (about 0.01 Pa), it transforms into the ...
The Ellingham diagram plots the Gibbs free energy change (ΔG) for each oxidation reaction as a function of temperature. For comparison of different reactions, all values of ΔG refer to the reaction of the same quantity of oxygen, chosen as one mole O (1 ⁄ 2 mol O 2) by some authors [2] and one mole O 2 by others. [3] The diagram shown ...
So-called noble metals, such as gold and platinum, resist direct chemical combination with oxygen, and substances like gold(III) oxide (Au 2 O 3) must be formed by an indirect route. The alkali metals and alkali earth metals all react spontaneously with oxygen when exposed to dry air to form oxides, and form hydroxides in the presence of oxygen ...
Rather than combustion, organisms rely on elaborate sequences of electron-transfer reactions, often coupled to proton transfer. The direct reaction of O 2 with fuel is precluded by the oxygen reduction reaction, which produces water and adenosine triphosphate. Cytochrome c oxidase affects the oxygen reduction reaction by binding O 2 in a heme ...
Chemical looping combustion (CLC) uses two or more reactions to perform the oxidation of hydrocarbon-based fuels. In its simplest form, an oxygen-carrying species (normally a metal) is first oxidized in the air forming an oxide. This oxide is then reduced using a hydrocarbon as a reducer in a second reaction.