Cobaltous Nitrate

Rinmann s green, ZnCojO. A spinel formed when cobalt nitrate solution is placed on zinc oxide and the mixture heated to redness. The green colour forms a delicate test for Zn. 

Cobalt(II) nitrate hexahydrate [10026-22-9], Co(N02)2 6H20, is a dark reddish to reddish brown, monoclinic crystalline material containing about 20% cobalt. It has a high solubiUty in water and solutions containing 14 or 15% cobalt are commonly used in commerce. Cobalt nitrate can be prepared by dissolution of the simple oxide or carbonate in nitric acid, but more often it is produced by direct oxidation of the metal with nitric acid. Dissolution of cobalt(III) and mixed valence oxides in nitric acid occurs in the presence of formic acid (5). The ttihydrate forms at 55°C from a melt of the hexahydrate. The nitrate is used in electronics as an additive in nickel—ca dmium batteries (qv), in ceramics (qv), and in the production of vitamin B 2 [68-19-9] (see Vitamins, VITAMIN B22)-... 

Trinitroso-3-methyl nitraminoanisole Trinitrotetramine cobalt nitrate... 

Chemical Designations - Synonyms Cobalt (II) Nitrate Cobaltous Nitrate Cobaltous Nitrate Hexahydrate Chemical Formula Co(NOj)2 6H20. 

Silver nitrate -f triglycerides, saturated and heat to 230 to 250 °C phosphotungstic monounsaturated alcohols acid + cobalt nitrate [205, 206]... 

The successful introduction of silver nitrate leads us to test other nitrates. In particular some transition metal nitrates have even lower melting temperatures (=55°C for cobalt nitrate). 

Fig. 8. CNTs filled with CoO filaments produced by thermal treatment of enclosed cobalt nitrate. Note the small diameter of the CoO filaments (= 2 nm).

Using the data obtained from the silver nitrate experiments, we have derived a simple approximation to calculate the cavity polarisability as a function of diameter [22]. If we apply this model to cobalt nitrate, the derived threshold for filling is 0.8 nm [32] this result qualitatively agrees with our observations that cobalt nitrate-filled cavities are much narrower ( 2 nm) than obtained with silver nitrate (= 4 nm). 

Process for manufacture of artificial essence of violets consisting in causing lemon-grass oil, alcohol, acetone, and concentrated solutions of salts of hj-pochlprous acid to react on one another at a boiling temperature, cobaltous nitrate being added if desired. 

Kobalto-. cobaltous, cobalto-, cobalt(II). -chlorid, n. cobaltous chloride, cobalt(II) chloride, -cyanwasserstoff, m., -cyanwasser-stoffs ure, /. cobaltocyanic acid, -nitrat, n. cobaltous nitrate, cobalt(II) nitrate, -oxyd, n. cobaltous oxide, cobalt (II) oxide, -salz, n. cobaltous salt, cobalt(IJ) salt, -sulfat, n. cobaltous sulfate, cobalt(II) sulfate, -sulfid, n. cobaltous sulfide, cobalt (II) sulfide, -verbindung, /. cobaltous compound. cobalt(II) compound. 

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%. 

Carbonyl Nitric Oxides. Another group of metal-carbonyl complexes, worthy of investigation as CVD precursors, consists of the carbonyl nitric oxides. In these complexes, one (or more) CO group is replaced by NO. An example is cobalt nitrosyl tricarbonyl, CoNO(CO)3, which is a preferred precursor for the CVD of cobalt. It is a liquid with a boiling point of 78.6°C which decomposes at 66°C. It is prepared by passing NO through an aqueous solution of cobalt nitrate and potassium cyanide and potassium hydroxide. ... 

Bimetallic Co-Mo oxide specimens were prepared via co-impregnation of calculated amounts of cobalt nitrate and ammonia heptamolybdate on y-alumina to achieve a total metal loading of 20wt% with an equimolar Co Mo ratio. Nitridation of catalysts was carried in a fixed bed... 

A 20 wt% of Co/TiOa was prepared by the incipient wetness impregnation. A designed amoimt of cobalt nitrate [Co(N03) 6H20] was dissolved in deionized water and then impregnated onto TiOj containing various ratios of rutileianatase obtained from above. The catalyst precursor was dried at 110°C for 12 h and calcined in air at 500°C for 4 h. 

Cobalt nitrate has the typical dangerous reactions of metal nitrates. Two accidents during which violent detonations occurred were reported. One of them happened when a mixture of this nitrate with powder carbon was ground up. The other took place when a tetraammonium hexacyanoferrate/cobalt nitrate mixture was heated to 220°C. It typifies incompatibiiity of the cyano group with oxidants. 

To 1.0 mL of the test solution, add 3.0 mL of dilute sodium hydroxide solution and 3.0 mL of water and 1.0 mL of a 100 g/L solution of cobalt nitrate. The test is positive if violet precipitate is formed. The precipitate dissolves in methylene chloride [10,11]. 

The more active cobalt catalyst for pyrolytic reactions was prepared by microwave calcination of cobalt nitrate which was converted to cobalt oxide by rapid microwave heating [7]. 

Other Methods of Preparation.—Ethyl 2-(D-ara6i no-tetrahydroxybutyl)-5-methyl-4-furoate has been prepared by heating D-glucose plus ethyl acetoacetate in aqueous alcohol without a catalyst,1 or from the same reagents (1 g. and 0.5 ml., respectively) in 0.5 ml. of 96% ethanol plus 1.5 ml. of water at room temperature in the presence of ferric chloride, zinc chloride (with small quantities of hydrochloric acid or of sodium hydroxide), cupric chloride, ferric sulfate, zinc sulfate, aluminum chloride, nickel chloride, or cobalt nitrate.18... 

Cobalt-on-alumina catalysts with increased dispersion and catalytic activity are prepared by addition of mannitol to the cobalt nitrate solution prior to impregnation. Thermogravimetric analysis (TGA) and in situ visible microscopy of the impregnation solution show that the organic compound reacts with cobalt nitrate, forming a foam. The foam forms because significant amounts of gas are released through a viscous liquid. The structure of the foam is retained in the final calcined product. It is this effect that is responsible for the increased dispersion. 

One way in which cobalt dispersion can be increased is the addition of an organic compound to the cobalt nitrate prior to calcination. Previous work in this area is summarized in Table 1.1. The data are complex, but there are a number of factors that affect the nature of the catalyst prepared. One of these is the cobalt loading. Preparation of catalysts containing low levels of cobalt tends to lead to high concentrations of cobalt-support compounds. For example, Mochizuki et al. [37] used x-ray photoelectron spectroscopy (XPS) and temperature-programmed reduction (TPR) to identify cobalt silicate-like species in their 5% Co/Si02 catalysts modified with nitrilotriacetic acid (NTA). The nature of the support also has... 

As described above, understanding the mechanism of the dispersion increase is a difficult task. In this work we compare a catalyst prepared by cobalt nitrate impregnation onto alumina with one modified by the addition of mannitol, and use TGA and in situ microscopy to investigate the increased dispersion. Mannitol is a sugar alcohol that is structurally similar to sorbitol [31], as shown in Figure 1.1. 

Cobalt nitrate hexahydrate (97%) and D-mannitol (99%) were obtained from Alfa Aesar and used as received. Alumina HP14-150 is a gamma alumina with surface area around 150 m2 g which was supplied by Sasol and used as received. 

The unmodified catalyst was prepared by dissolving cobalt nitrate hexahydrate (19.76g, 68 mmol) in water (9 ml) and impregnating the solution into alumina (16.0 g). The catalyst was dried at 105°C in static air for 3 h and calcined at 400°C for 1 h. The mannitol-containing catalyst was prepared as described above, except that mannitol (2 g, 11 mmol) was dissolved in the cobalt nitrate solution prior to impregnation. The Co/mannitol ratio was 6.2. 

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