Hydrochloric acid with cobalt chloride

Cobalt(II) chloride hexahydrate [7791-13-1], C0CI2 6H20 is a deep red monoclinic crystalline material that deflquesces. It is prepared by reaction of hydrochloric acid with the metal, simple oxide, mixed valence oxides, carbonate, or hydroxide. A high purity cobalt chloride has also been prepared electrolyticaHy (4). The chloride is very soluble in water and alcohols. The dehydration of the hexahydrate occurs stepwise ... 

A series of complex silico-arsenides has been obtained 6 by melting metals with silicon and an excess of arsenic under a layer of molten cryolite and sodium chloride. The following have thus been prepared copper silico-arsenide, a grey crystalline brittle mass zinc silico-arsenide, which behaved as above with hydrochloric acid iron, cobalt and nickel siMco-arsenides, of composition M2SisAs4, similar in appearance to the copper compound. When platinum was treated in the same way, a hard white product of indefinite composition was obtained, almost insoluble in nitric acid. 

For this reaction, charcoal is a catalyst if this is omitted and hydrogen peroxide is used as the oxidant, a red aquopentammino-cobalt(lll) chloride, [Co(NH3)jH20]Cl3, is formed and treatment of this with concentrated hydrochloric acid gives the red chloro-p0itatnmino-coba. t(lll) chloride, [Co(NH3)5Cl]Cl2. In these latter two compounds, one ammonia ligand is replaced by one water molecule or one chloride ion it is a peculiarity of cobalt that these replacements are so easy and the pure products so readily isolated. In the examples quoted, the complex cobalt(III) state is easily obtained by oxidation of cobalt(II) in presence of ammonia, since... 

When cobalt(II) chloride was dissolved in water, a pink solution A was formed. The addition of concentrated hydrochloric acid to A gave a blue solution B. If solution A was treated with concentrated ammonia solution a blue-green precipitate was formed upon addition of further ammonia solution followed by the passage of air through the mixture, an orange-red solution C was produced. 

A compound of cobalt has the formula Co(NH3)jtCl. 0.500 g of it was dissolved in 50.00 cm M hydrochloric acid the excess acid required 40.00 cm M sodium hydroxide solution to neutralise it. Another 0.500 g portion of the compound was dissolved in water and allowed to react with excess silver nitrate solution. 0.575 g of silver chloride was precipitated. 

Arsonium salts have found considerable use in analytical chemistry. One such use involves the extraction of a metal complex in aqueous solution with tetraphenyiarsonium chloride in an organic solvent. Titanium(IV) thiocyanate [35787-79-2] (157) and copper(II) thiocyanate [15192-76-4] (158) in hydrochloric acid solution have been extracted using tetraphenyiarsonium chloride in chloroform solution in this manner, and the Ti(IV) and Cu(II) thiocyanates deterrnined spectrophotometricaHy. Cobalt, palladium, tungsten, niobium, and molybdenum have been deterrnined in a similar manner. In addition to their use for the deterrnination of metals, anions such as perchlorate and perrhenate have been deterrnined as arsonium salts. Tetraphenyiarsonium permanganate is the only known insoluble salt of this anion. 

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... 

For a decade or so [CoH(CN)5] was another acclaimed catalyst for the selective hydrogenation of dienes to monoenes [2] and due to the exclusive solubility of this cobalt complex in water the studies were made either in biphasic systems or in homogeneous aqueous solutions using water soluble substrates, such as salts of sorbic add (2,4-hexadienoic acid). In the late nineteen-sixties olefin-metal and alkyl-metal complexes were observed in hydrogenation and hydration reactions of olefins and acetylenes with simple Rii(III)- and Ru(II)-chloride salts in aqueous hydrochloric acid [3,4]. No significance, however, was attributed to the water-solubility of these catalysts, and a new impetus had to come to trigger research specifically into water soluble organometallic catalysts. 

Cobalt(II) chloride is prepared by the action of cobalt metal or its oxide, hydroxide, or carbonate with hydrochloric acid ... 

Cobalt(II) oxide reacts with acids forming their cobalt(II) salts. Reactions with sulfuric, hydrochloric and nitric acids yield sulfate, chloride and nitrate salts, respectively, obtained after the evaporation of the solution ... 

The double compound, [Cr(NH3)6H20][Cr(CN)8], is precipitated from the aquo-pentammino-chloride on addition of potassium chromi-cyanide it separates as a sparingly soluble yellow crystalline powder, and on heating with concentrated hydrochloric acid decomposes with formation of ehloro-pentammino-chloride. The ferricyanide, [Cr(NH3)B H20][Fe(CN)6], is precipitated from a dilute solution of the aquo-pentammino-ehloride on addition of potassium ferricyanide, and crystallises in vellowish-brown prisms. The cobalti-cyanide, [Cr(NH3)5H20] [Co(CN)6], obtained, by the addition of potassium cobalti-cyanide, in yellowish-brown crystals, is isomeric with the chromi-eyanide of aquo-pentammino-cobalt, [Co(NH3)sH20][Cr(CN)6]. 

Hexammino - cobaltic Chloride, or Luteo-cobaltic Chloride, [Co(NH3)8]Cl3.—Several methods of preparation have been described. The best method is that of Jorgensen,1 whereby the salt is prepared by warming chloro-pentammino-cobaltic chloride, [Co(NH3)5C l]Cl2. in a pressure flask with 20 per cent, aqueous ammonia and ammonium chloride for several hours with constant shaking. After cooling, the mixture is removed from the flask and ammonia allowed to evaporate. The liquid is then diluted, hydrochloric acid added, and the whole heated on the water-bath, thus changing any aquo-pentammino-chloride into ehloro-pentammino-ehloride. More concentrated hydrochloric acid is added and the mixture cooled and filtered. The residue on the filter consists of ammonium chloride, chloro-pentammino-chloride, and hexammino-cobaltic chloride. Ammonium chloride is removed by treating with a 20 per cent, solution of hydrochloric acid, and the residue is then treated on a filter with cold water in which chloro-pentammino-cobaltic chloride is insoluble and hexammino-cobaltic chloride soluble. The salt is precipitated from its warm solution by the addition of half its volume of concentrated hydrochloric acid. 

Aquo - pentammino - cobaltic Chloride, [ o(NH3)5.H20]C13, is also best prepared from the oxalate. The oxalate is moistened with water and brought into solution by the addition of normal hydrochloric acid. On the addition of concentrated acid the chloride is precipitated as an indistinctly crystalline brick-red powder. The salt is soluble in cold water, and is readily transformed into the aeido-salt on heating to 100° C. It also passes into the aeido-salt on heating in hydrochloric acid solution thus ... 

Diaqu o - tetrammino - cobaltic Chloride, [Co(NHs)4.(H20)2]C13.— The salt has been obtained water free as above or containing one molecule of water, [Co(NH3)4.(H20)2]Cl3.IT2Q. This salt is also prepared from the carbonato-salt by dissolving it in water containing a little hydrochloric acid. The liquid is then cooled in ice and the diaquo-tetrammino-cobaltic chloride precipitated by the addition of concentrated hydrochloric acid. It is filtered off, washed with acid, then with 95 per cent, alcohol, and dried in air. 

Triaquo-triammino-cobaltic Chloride, [Co(NH3)3(H20)3]C13, is produced by dissolving trinitrato-triammine cobalt in water with the addition of a little acetic acid and allowing the liquid to stand for twenty hours. It is then cooled and treated with hydrochloric acid at 0° C., when a yellowish-red crystalline powder is precipitated. This is quickly separated from the mother-liquor and dried on a porous plate.2 Other triaquo-triammino-salts have been prepared. 

Hydroxo-aquo-diethylenediamino-cobaltic Chloride, [Co en2 H20.0H]C12.H20, is a brownish-red crystalline powder which is easily converted into the diaquo-salt on treatment with concentrated hydrochloric acid. 

The sulphate, [Co(NTIs)3N02]S04, crystallises in brownish-yellow leaflets or prisms, is soluble in hot water and slightly soluble in cold water. In neutral solution it decomposes, and prolonged heating with hydrochloric acid transforms it into chloro-pentammino-cobaltic chloride. 

Nitrato-pentammino-cobaltic Chloride, [Co(XH3)5X03]Clg, is formed by mixing finely powdered nitrato-pentammino-nitrate with water containing a small quantity of dilute sulphuric acid and allowing the solution to Tun slowly into excess of well-cooled hydrochloric acid. The precipitate formed is collected and washed with acid and then with alcohol. It crystallises in reddish-violet octahedra which are slightly soluble in cold water, and if crystallised from water containing hydrochloric acid it is transformed into chloro-pentammino-cobaltic chloride,... 

The substance is best prepared by dissolving cobaltous carbonate in the smallest possible quantity of hydrochloric acid, treating the cold solution with a mixture of concentrated aqueous ammonia and ammonium carbonate, and oxidising by means of a stream of air drawn through the liquid. When oxidation is complete ammonium chloride is added and the whole evaporated to a syrup dilute hydrochloric acid is added to remove carbon dioxide, and the liquid is saturated with ammonia gas to decompose any tetrammino-salt formed. On the addition of concentrated hydrochloric acid the salt crystallises out on cooling.6... 

Dinitro-tetrammino-cobaltic Chloride, [Co(NH3)4(N03)2] Cl, is obtained from the sulphate by treating it with barium chloride, or by heating a solution of dichloro-tetrammino-cobaltic ehloride in dilute acetic acid with sodium nitrite.3 It is soluble in water, and separates from solution in reddish-yellow rhombic crystals. The aqueous solution, however, decomposes on standing. If a cold aqueous solution be treated with dilute nitric acid the nitrate separates concentrated hydrochloric acid decomposes the salt with formation of the chloro-nitro-chloride, [Co(NH3 )4 (NO 2)C1] Cl.3... 

Oxalato-tetrammino-cobaltic Chloride, [Co(NH3)4(C204)]C1, is prepared by dissolving chloro-aquo-tetrammino-eobaltic chloride in an aqueous solution of oxalic acid and heating the mixture for some time. The oxalato-compound gradually crystallises from the warm solution, and the crystals are collected and washed on the filter with alcohol until the filtrate is free from chlorine and from oxalic acid. It crystallises in carmine-red six-sided plates if dissolved in concentrated sulphuric acid and concentrated hydrochloric acid is added to the liquid, it is transformed into dichloro-tetrammino-cobaltic chloride. Sodium nitrite and acetic acid convert it into dinitro-tetrammino-cobaltic chloride.1... 

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. 

Dictiloro - aquo - triammino - cobaltic Chloride (Dichro -chloride), [Co (NH,)3H20.Cl 2]Cl, may be prepared from trinitrato-tri-ammine cobalt by treatment with concentrated sulphuric acid and subsequent treatment with concentrated hydrochloric acid, or from trinit.ro-triammino-cobalt on treatment with concentrated hydrochloric acid.2... 

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