Cobalt chloride, anhydrous

Cobalt chloride (anhydrous) was obtained from Aesar, L-histidine hydrochloride from Sigma, N-benzyl-L-histidine from Vega, tetraethylene pentamine (tetren) was obtained from Aldrich. Hater was deionized via a Barnstead Nanopure II ion exchange unit. Cells and electrodes for voltammetry were standard Bioanalytical Systems or Pine Instrument controlled by BAS lOOA, BAS-CV27 or Pine Instrument RDE4 potentiostats and instrumentation. Spectroelectrochemistry was accomplished using a standard... 

Two general approaches have been used to prepare the cobalt powders. The first method(34,37,42) used 2.3 equivalents of lithium along with naphthalene as an electron carrier in DME to reduce anhydrous cobalt chloride to a dark gray powder, L Use of cobalt bromides or iodides gave a... 

Three color changes were observed blue, violet and red. From the information provided, the blue form appeared to be the anhydride, CoCl2. When exposed briefly to air containing water vapor, the anhydrous cobalt chloride turned violet, CoCl2 2H20. Upon further standing in air, the dihydrate was converted to the fully hydrated form, CoCl2 6 H20. The color of the anhydride-hydrate depended upon the relative humidity of the air to which it was exposed. 

Tetrammino - cobaltous Chloride, [Co(NH3)4]C12, is produced if ammonia gas is passed over anhydrous cobaltous chloride. Ammonia is rapidly absorbed, increase in volume takes place, and a reddish-white powder is formed. This decomposes on heating with evolution of ammonia, leaving a residue of cobalt oxide. 

Tests to show the presence of water using cobalt chloride paper and anhydrous copper(n) sulfate. 

Water (H20) Colourless (odourless) No effect - neutral Turns blue cobalt chloride paper pink Turns anhydrous copper(n) sulfate from white to blue... 

As in many other o-substituted Gamino systems, the interaction of the o-azo group was also discovered accidentally. Price78 7B observed that the ortho substituted azobenzenes (X and Y = OH, NH2, NHMe, etc.) form stable 2 1 cobalt chloride complexes with anhydrous... 

Cobalt chloride readily dissolves in ether saturated with hydrogen chloride, yielding a blue solution. Nickel chloride, on the contrary, is insoluble, being precipitated as the yellow, anhydrous salt. The separation of nickel from cobalt chloride may thus be effected as follows ... 

In another four experiments anhydrous cobalt chloride was analysed for chlorine by titration with silver ... 

In 1860 Dumas analyses of anhydrous cobalt chloride appeared.1 Five analyses gave the following mean result ... 

With the subsequent invention of fused quartz vessels it became possible to prepare pure anhydrous cobalt chloride. Accordingly, in 1906, Baxter and Coffin 1 prepared and analysed this salt in the customary Harvard manner, the results being as under ... 

Cobalt Sesquiphosphide, CoJL, is obtained3 by raising anhydrous cobalt chloride to red heat in phosphorus vapour. 

C. Add 1 mL of a 1 100 aqueous solution and 2 mL of a 1 50 solution of potassium ferrocyanide to 2 mL of cobaltous chloride TS. An emerald green color develops immediately. Assay Not less than 98.0% of C9H19N07, calculated on the anhydrous basis. 

Figure 11-13 shows a common hydrate of cobalt(ll) chloride. If 11.75 g of this hydrate is heated, 9.25 g of anhydrous cobalt chloride remains. What is the formula and name for this hydrate ... 

The Hammond Co. supplies an indicating form which turns from blue to red when exhausted. It is prepared by impregnating the surface of the calcium sulfate granules with 3.5-5% of anhydrous cobalt chloride. The blue cobalt salt is indifferent to aprotic solvents insoluble in water (benzene) or partially soluble in water (diethyl ether), but is leached off by water-miscible solvents, both protonic (ethanol, acetic acid) tmd aprotic (dimethylformamide, dimethyl sulfoxide, triglyme). 

The anhydrous chloride is prepared by heating, and it dissolves readily in alcohol with a deep blue color. A saturated blue solution to which water is carefully added (to be sprayed from a wash bottle) becomes first violet and then, with more water, red. (According to A. Winkler, alcoholic cobalt chloride solution can be used for an approximate colorimetric water determination). 

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