Manganese oxide properties

Tebo, B.M., Bargar, J.R., Clement, B.G., Dick, G.J., Murray, K.J., Parker, D., Verity, R. Webb, S.M. (2004) Biogenic manganese oxides Properties and mechanisms of formation. Annual Review Earth and Planetary Science 32, 287-328. 

Analysis. Butenes are best characterized by their property of decolorizing both a solution of bromine in carbon tetrachloride and a cold, dilute, neutral permanganate solution (the Baeyer test). A solution of bromine in carbon tetrachloride is red the dihaUde, like the butenes, are colorless. Decoloration of the bromine solution is rapid. In the Baeyer test, a purple color is replaced by brown manganese oxide (a precipitate) and a colorless diol. These tests apply to all alkenes. 

Manganese and iron oxidation are coupled to cell growth and metabolism of organic carbon. Microbially deposited manganese oxide on stainless and mild steel alters electrochemical properties related to the potential for corrosion. Iron-oxidizing bacteria produce tubercles of iron oxides and hydroxides, creating oxygen-concentration cells that initiate a series of events that individually or collectively are very corrosive. 

Luo, J., Zhang, Q., Garcia-Martinez, J. and Suib, S.L. (2008) Adsorptive and acidic properties, reversible lattice oxygen evolution, and catalytic mechanism of cryptomelane-type manganese oxides as oxidation catalysts. Journal of the American Chemical Society, 130, 3198-3207. 

In the preparation of microporous manganese oxide materials different chemical properties were observed for the microwave and thermal preparations. In the conversion of ethylbenzene to styrene the activity and selectivity of the materials was different [26]. 

Morales F., de Smit E., de Groot F.M.F., Visser T., and Weckhuysen B.M. 2007. Effects of manganese oxide promoter on the CO and H2 adsorption properties of titania-supported cobalt Fischer-Tropsch catalysts. J. Catal. 246 91-99. 

Isoelectronic mesoporous Ti02 has been prepared by the same method but it is also not stable to template removal (224, 227). Hexagonal and cubic manganese oxide mesostructures (MOMS) have been prepared (228). Layered Mn(OH)2 is combined with CTAB and stirred at 75°C for 12 h. Depending on the CTAB concentration, either hexagonal MOMS-1 or cubic MOMS-2 is formed. The MOMS phases are apparently stable to calcination and exhibit semiconducting properties. 

NO reduction by CO, 28 162 olefin oxidation, 27 241,242 water-gas shift, 28 118,119 coordination number, 30 265 -copper alloy, 26 75 -copper alloy films thermodynamic properties of, 22 118 -copper oxide, 27 90,91 -manganese oxide, 27 91,92... 

Mn,tCo3 t04) phase. This spinel oxide is broken up during reduction to make MnO t and a metallic surface. Due to the pre-existence of this Mn-M interaction, electronic promotion is much more easily achieved after reduction as well. It is worthwhile to mention that Mn,tCo3 t04 compounds are well studied in the literature, because they have important electrocatalytical properties. More specifically, spinel-type manganese oxides are widely used as precursors in the preparation of X-Mn02 ([ ]A[Mn2]B04], an oxide of technical interest due to its application as a cathode material for rechargeable cells. " ... 

Write the formulas of all the manganese oxides and compare their properties. How and why do the properties change in the series of man anese hydroxides corresponding to its different oxidation states Which of the manganese hydroxides are unstable in air ... 

Common chemical properties The alkali metals are so chemically reactive that they are never found free in nature. Sodium and potassium react explosively with water to produce hydrogen gas. The alkaline earth metals are not quite as reactive as the alkali metals. The alkali metals react with water but not explosively. The transition metals are generally the least reactive of all the metals. However, when they combine with other elements, they form a large variety of colored compounds. Chromium oxide is green, titanium oxide and zinc oxide are white, manganese oxide is purple, and iron oxide is ochre. 

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