Cobalt monohydrate

Sulfite reacts readily with oxygen, particularly under hot, alkaline conditions, but the reaction rate is slow in colder, neutral waters thus complete FW deaeration cannot be guaranteed. Consequently, it is standard practice to add a small amount of catalyst to the sulfite. The catalyst is usually cobalt sulfate [more properly, cobaltous sulfate (CoS04) supplied as an anhydrous, monohydrate, or heptahydrate salt] or sometimes cobaltous nitrate. The catalyst is added to 100% sodium sulfite at a concentration level of 0.2 to 0.25%. 

C9H12N3OsP Co h2o Cytidine 5 -[cobalt(II) phosphate], monohydrate CYTPCO10 38 505... 

CobaltCII) sulfate monohydrate, 7 231 Cobalt sulfide, poisons in representative reactions, 5 258t CobaltCII) sulfide, uses, 7 241t CobaltCII) thiocyanate, uses, 7 241t Cobalt tin alumina blue spinel, formula and DCMA number, 7 348t... 

The anhydrous salt of cobalt(II) suhate is a red orthogonal crystal density 3.71g/cm3 melts above 700°C the monohydrate is red orthogonal crystal having a density of 3.08 g/cm the heptahydrate is a pink salt, monoclinic prismatic crystals, density 2.03 g/cm heptahydrate dehydrates to hexahydrate at 41°C and converts to monohydrate at 74°C the anhydrous salt and heptahy-drates are soluble in water monohydrate slowly dissolves in boiling water. 

Hydrate Isomerism.—As its name implies, this depends on the position of water in the molecule, just as in the case of the acido compounds. If two or more molecules of water are present in a molecule of ammine, the water may be present within the co-ordination complex or outside of it. For instance, the compound Cr en2.(H20)2.Br3 exists in isomeric forms. It may have all the water within the complex, in which case the formula will be [Cr en2(H20)2]Br3. In solution the whole of the bromine is precipitated by silver nitrate. On the other hand, the compound may have one molecule of water in the complex and the other outside, in which case the formula is [Cr en2(IT20)Br]Br2.H20, and only two-thirds of the bromine are precipitated by silver nitrate. Another example of this kind occurs in the cobalt series chloro-aquo-tetrammino-cobaltic chloride, [Co(NTI3)4Cl.H20]Cl2, is violet in colour, and is isomeric with dichloro-tetrammino-cobaltie chloride monohydrate, [Co(N1I3)4CI2]C1.H20, which is green. 

A solution of chloro-diaquo-triammino-cobaltic bromide is blue in colour, and on the addition of hydrobromie acid the isomeric chloro-bromo-aquo-triammino-eobaltic bromide monohydrate, [Co(NH3) 3(H 20) ClBr]Br.H20, separates in brown needles even at temperatures below... 

The acid chloride, [Co en2Cl2]Cl.HC1.2H20, is formed by mixing a solution of cobaltous chloride with an aqueous solution of ethylene-diamine monohydrate and oxidising the mixture with air. Concentrated hydrochloric acid is then added and the whole heated on a water-bath for one hour. The liquid is allowed to stand, when crystals separate, and are filtered and washed with concentrated hydrochloric acid.2 The salt crystallises in dark green rhombic plates. It is soluble in water, though less soluble than the normal salt, and on heating to 100° C. is transformed into the normal salt. 

C. F. Rammelsberg also prepared what he thought to be a monohydrated nickel iodate analogous with his cobalt salt F. W. Clarke similarly reported a hexahydrated nickel iodate, and A. Ditte, green prismatic crystals of trihydrated nickel iodate. 

To a solution of compound 166 (306 mg, 1 mmol) [Eq. (30)] in 12 mL of CH2CI2 was added in one portion cobalt carbonyl (343 mg, 1.1 mmol) at room temperature. The mixture was stirred for 3 h, and then anhydrous 4-methylmorpholine IV-oxide monohydrate (850 mg, 6.3 mmol) was slowly added and stirring was continued for 5 h more. Part of the solvent was evaporated, and the suspension was purified by flash chromatography (hexane-EtOAc) to provide compound 168 (194 mg, 66%) [a]D —17° (c 2.3, CHC13). 

Colloidal manganese arsenate may be obtained in an analogous way to that described for cadmium and cobalt arsenates.7 If concentrated solutions of manganous chloride and potassium dihydrogen arsenate are mixed at the ordinary temperature, a solid jelly is formed, which remains stable for weeks but finally, rose-coloured crystals separate and the jelly partly liquefies.8 The essential constituent of the jelly appears to be the monohydrogen arsenate, MnHAs04, and the crystals are the monohydrate, MnHAs04.Ha0. 

A stream of carbon dioxide is bubbled through a mixture of 133 ml. (1.64 moles) of ethylenediamine monohydrate and 133 ml. of water cooled in ice. The stream of carbon dioxide is maintained during the entire preparation. A solution of 195 g. (0.82 mole) of cobalt(II) chloride hexahydrate in 175 ml. of water at room temperature is added to the cold solution, which is continually stirred. The addition of the cobalt(II) salt causes a violent evolution of carbon dioxide gas, and the solution becomes red-violet. (Sometimes the mixture coagulates and becomes gel-like.) The cooling and the stirring are continued, and the mixture is oxidized by dropwise addition of 200 ml. of 30%... 

A279 in Table C as entry Co 15, Aquapentam-mine cobalt (III) Perchlorate Monohydrate ... 

Both dextro- and levo-tris (ethylenediamine) cobalt (III) iodide monohydrate crystallize in deep orange needles or rhombs. The racemic phase which separates as the 1-hydrate is much less soluble in water. Racemization ensues... 

In the cold the saturated solution is rose-coloured, like the crystalline hexahydrated salt. On warming it becomes violet between 25° and 50° C., above which latter temperature it is blue. This is explained by some as due to a change in hydration of the cobalt salt in solution from the red hexahydrate, through the violet monohydrate, to the blue anhydrous salt. Certainly the changes in colour correspond to breaks in the solubility curve as shown in Fig. I.1 A similar change in colour from red to blue likewise occurs with increase of concentration of the solution. 

McConnell and Hanes 1 claim to have obtained the monohydrate or cobaltous acid, H2Co03, by the action of hydrogen peroxide upon cobaltous hydroxide in aqueous suspension.2 If the acid can exist at all in the free state it is very unstable, although some of its salts are well defined. 

The monohydrate, CoS04.H20, is precipitated on adding excess of concentrated sulphuric acid to an aqueous solution of cobalt sulphate12 by evaporation of an add solution of the salt13 on the sand-bath until... 

As prepared in this manner cobalt sulphate monohydrate is a red, crystalline powder, very slowly soluble in water. Exposed to moist air it slowly absorbs water. At red heat it loses water, becoming anhydrous. Density 3-125. 

Cobalt Molybdate, CoMoO 4, occurs in nature as the mineral pateroite. It may be prepared artificially by fusing sodium molybdate with the chlorides of sodium and cobalt. The product is greyish green in colour. The monohydrate, CoMo04.H20, has also been prepared.3... 

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