Hydrated copper carbonate

Typically the internals of the coil show pits and pinholes and may even perforate. Corrosion debris is evident, usually containing green hydrated copper carbonate (CuC03 nH20) and red cuprous oxide (Cu20). 

Problems with heating coils Internal coil corrosion Note corrosion debris is green hydrated copper carbonate Cu[11IC03 nH20 red cuprous oxide Cu20 /ntemal coil deposition Acid corrosion from soft water. Pinhole corrosion from 02 and C02. Erosion corrosion over 6 ft/s flow. Hard water scale from hard water. 

Cyanos was a blue gem of much value, and it has been identified as the stone called lapis lazuli, though Theophrastus also refers to another kind of cyanos, which has in it chrysocolla. This doubtless refers to our azurite, a hydrated copper carbonate, used by the ancients as a blue pigment, and known to the Latins as armenus, so named after the locality, Armenia, from which it was largely obtained. 

Copper is a moderately active metal. It dissolves in most acids and in alkalis. An alkali is a chemical with properties opposite those of an acid. Sodium hydroxide, commonly found in bleach and drain cleaners, is an example of an alkali. An important chemical property of copper is the way it reacts with oxygen. In moist air, it combines with water and carbon dioxide. The product of this reaction is called hydrated copper carbonate (Cu2(0H)2C03), which changes copper s reddish-brown color to a beautiful greenish color, called a patina. Copper roofs eventually develop this color. 

Azurite is a bright blue hydrated copper carbonate mineral of composition Cu3(C03)2(0H)2. Isomorphous with the green mineral malachite (. v.), the isostructural synthetic analogue. 

The solid readily dissolves chemically in concentrated hydrochloric acid, forming a complex, and in ammonia as the colourless, linear, complex cation [H3N -> Cu <- NHj] (cf AgCl) if air is absent (in the presence of air, this is oxidis to a blue ammino-copper(II) complex). This solution of ammoniacal copper(I) chloride is a good solvent or carbon monoxide, forming an addition compound CuCl. CO. H2O, and as such is used in gas analysis. On passing ethyne through the ammoniacal solution, a red-brown precipitate of hydrated copper(I) dicarbide (explosive when dry) is obtained ... 

Add in turn 55 g. of anhydrous sodium carbonate, 27 g. of powdered arsenious oxide and i g. of hydrated copper sulphate to 175 ml. of water in a 2 litre beaker, and heat the stirred mixture until an almost clear solution is obtained then immerse the stirred solution in ice-water, and cool it to 5°. 

Some salts, such as sodium chloride, copper carbonate and sodium nitrate, crystallise in their anhydrous forms (without water). However, many salts produce hydrates when they crystallise from solution. A hydrate is a salt which incorporates water into its crystal structure. This water is referred to as water of crystallisation. The shape of the crystal hydrate is very much dependent on the presence of water of crystallisation. Some examples of crystal hydrates are given in Table 8.6 and shown in Figure 8.20. 

A mixture of 50 g. (0.24 mole) of 4-hromoisoquinoline (p. 50), 160 ml. of concentrated ammonium hydroxide solution, and 3 g. of hydrated copper sulfate is heated in a shaking autoclave at 165-170° for 16 hours. The reaction mixture is made alkaline with dilute sodium hydroxide solution and extracted with five lOO-mh"portions of benzene. After being dried over anhydrous potassium carbonate and treated with charcoal, the benzene solution is concentrated to a volume of 70 ml. Cooling precipitates 24 g. (70%) of 4-aminoiso-quinoline, m.p. 107-107.5°. Two recrystallizations from benzene raise the melting point to 108.5°. 

Dichlorotetracarbonyldirhodium has been obtained by the action of carbon monoxide at high temperature and pressure on a mixture of anhydrous rhodium(III) chloride and finely divided copper powder and by reaction of rhodium(III) chloride 3-hydrate with carbon monoxide saturated with methanol at moderate temperatures and atmospheric pressure. The preparation described here is a modification of the latter method, without use of methanol. This procedure is considerably simpler than the recently described preparation which involves adsorption of rhodium chloride on silica gel, chlorination, and subsequent carbonylation. ... 

Ionization energies have been determined by p.e.s. for compounds in the two series (Me2N)3 Cl PS and (EtO)3 Cl PS (n —0—3), and the first ionization potential has been shown to correlate linearly with AG° values for complex formation with iodine in carbon tetrachloride. Re-examination of the reaction between tetramethyldiphosphine disulphide and hydrated copper(ii) chloride in ethanol shows the formation of a dinuclear copper(i) complex [(Me4P2S2)CuCl]2 as the major product, while its precursor, (Me4P2S2)CuCl2, is obtained in minor amounts. X-Ray structure determinations have been carried out on both compounds. 

Carbonic anhydrase (CA) is a zinc metalloenzyme involved in mammalian respiration, which catalyzes the hydration of carbon dioxide. Copper-complexed TPPC, competitively inhibits CA enzymatic activity as does copper-complexed TPPSj [32]. Experiments comparing the spectrophotometric characteristics of the two porphyrins in the presence of CA and apo-CA indicate that the zinc atoms in the active site of the enzyme are indeed involved in the interaction between the porphyrins and the enzyme. The metal-free porphyrins TPPSj and TPPC, do not inhibit the enzymatic activity of CA. Further, the spectrophotometric characteristics of these porphyrins in the presence of apo-CA were identical to those in the presence of wild-type CA, indicating the lack of involvement of the active site-coordinated zinc in the porphyrin-enzyme interaction for metal-free porphyrins. 

Copper is extremely resistant to atmospheric corrosion as it rapidly forms a complex green hydrated copper(I) oxide/carbonate film that prevents further corrosion. Copper is very suitable for underground services as it is extremely resistant to attack. Corrosion troubles occur when copper and steel pipes are joined together, because copper induces corrosion in steel objects joined to it by electrochemical action. 

After the decomposition of the fatty or oily matter in the autoclave, the aqueous solution of glycerine is withdrawn, and instead of decomposing the lime soap with acids, as in the ordinary process of making stearine, the inventor employs for its decomposition strong caustio soda or potash leys, or a solution of carbonate of soda or potash. The hydrat or carbonate solution is used in about the proportion of 7 per cent, of the alkaline base to from 60 or 70 per cent, of the fatty acid, these proportions being varied within certain limits j in all cases care must be taken Hiat the alkali shall be sufficient to combine with or saturate the whole of the fatty acid. The decomposition of the lime soap by means of the hydrate or carbonate of soda will result in the production of a soda soap, and where the hydrate or carbonate of potash is used for such decomposition the product will be potash soap, the lime in either case being precipitated in a more or less insoluble condition. The soaps obtained by this process may be finished in a soap-copper in the ordinary manner. 

The coupling of acetylenic iodides with copper sulfinates leads to the formation of uncommon acetylenic sulfones (Fig. 26). Sonication promotes this reaction, which can be made even easier by using a mixture of the sulfinic acid and commercial copper "carbonate" (a hydrated mixture of copper carbonate and hydroxide).i54 Successful results were also recorded in an extension using copper thiosulfonates and copper dimethyl phosphite. 

BROMIC ACID CADMIUM CYANIDE CALCIUM BISULFIDE CALCIUM BISULFITE CALCIUM CARBONATE CALCIUM CHLORIDE CALCIUM HYDROXIDE CALCIUM HYPOCHLORITE CALCIUM NITRATE CALCIUM SULPHATE CARBON DIOXIDE CARBON MONOXIDE CARBONIC ACID CASTOR OIL CAUSTIC POTASH CAUSTIC SODA CHLORAL HYDRATE CHLORIC ACID. 20% CHLORIDE (WATER) CHLORINE WATER CHROME ALUM CITRIC ACID COPPER CARBONATE COPPERCHLORIDE COPPER CYANIDE COPPER FLUORIDE... 

Cupric oxide or black copper oxide.) CuO. Mol. wt. 79.54 sp. gr. 6.4 decomposes at 1026°C. Insoluble in water and soluble in acids and NH4CI. Derived by the ignition of copper carbonate or copper nitrate, copper hydrate, or oxidation of lower oxides. 

Decomposition of model substances method The third method of calibration is by carrying out an experimental run using certain well studied model substances such as copper sulfate pentahydrate, calcium carbonate, calcium oxalate mono hydrate, potassium carbonate, sodium hydroxide, zinc oxalate dihydrate, and benzoic acid. These model substances show well resolved dehydration and decomposition temperatures over a wide temperature range. 

The anhydrous chloride is prepared by standard methods. It is readily soluble in water to give a blue-green solution from which the blue hydrated salt CuClj. 2H2O can be crystallised here, two water molecules replace two of the planar chlorine ligands in the structure given above. Addition of dilute hydrochloric acid to copper(II) hydroxide or carbonate also gives a blue-green solution of the chloride CuClj but addition of concentrated hydrochloric acid (or any source of chloride ion) produces a yellow solution due to formation of chloro-copper(ll) complexes (see below). 

Addition of water gives the hydrated nitrate Cu(N03)2.3H2O, the product obtained when copper (or the +2 oxide or carbonate) is dissolved in nitric acid. Attempts to dehydrate the hydrated nitrate, for example by gently heating in vacuo, yield a basic nitrate, not the anhydrous salt. 

Valentinite, see Antimony(III) oxide Verdigris, see Copper acetate hydrate Vermillion, see Mercury(II) sulflde Villiaumite, see Sodium fluoride Vitamin B3, see Calcium (+)pantothenate Washing soda, see Sodium carbonate 10-water Whitlockite, see Calcium phosphate Willemite, see Zinc silicate(4—)... 

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