Silver compounds elemental analysis

Levene15 reported that heating of 2-amino-2-deoxy-D-mannose (8) in the presence of silver oxide leads to a crystalline, nitrogen-free compound to which he attributed the structure of 2,5-anhydro-D-glucose on the basis of its elemental analysis. The possibility of interconversion between the two chair forms Cl (d) — 1C (d), which would bring the amino group at C-2 into equatorial orientation, has been postulated.22 Without excluding this possibility, it remains to be proved that the deamination by silver oxide does, indeed, proceed by... 

In 1943, Hieber and Lagally reported that the reaction of anhydrous rhodium trichloride with carbon monoxide at 80°C, under pressure, and in the presence of silver and copper as halogen acceptors, gave a black crystalline product which, on the basis of elemental analysis, was formulated as Rh4(CO)n 75). The exact nature of this compound was established 20 years later by Dahl using three-dimensional X-ray analysis which led to its reformulation as Rh6(CO)i6 53). This discovery can be regarded as the birthday of the chemistry of high nuclearity clusters. 

In some instances the method for carbon determination has to be modified, e.g., the determination of trace amounts of what is referred to as dissolved organic carbon in water after inorganic carbon has been removed. This type of carbon determination involves wet oxidation activated by silver ions in a solution of potassium persulphate in sulphuric acid. The oxidation of organic compounds gives carbon dioxide, which is adsorbed by molecular sieves. The molecular sieves are then heated in a flow of helium to desorb the carbon dioxide, the amount of which is measured by a TCD. The lowest concentration of organic carbon that can be measured in water is 0.2—2ppm [55]. The application of chromatographic elemental analysis to the determination of the total carbon content in water has been described [56]. 

The paramagnetic products of the one-electron oxidation, [CpReH2 P(p-XCgH4)3 2], are stable and the reversible potential shows a linear dependence with Hammett s Op parameter. These compounds, however, have not been isolated and have only been characterized, besides their cyclic voltammetric properties, by UV-visible spectroscopy for X = H and by the nature of the chemical decomposition products (see section 6.5.2). Two isolated members of this class were described later by Herrmann. The silver oxidation of Cp ReH(X)(PMe3)2 (X = H or Cl) yield salts of the corresponding cations, isolated as the triflate for X = H and the hexafluoroantimonate for X = Cl. No characterization other than elemental analysis and IR (no mention of Re-H frequencies) was given, however... 

Positive tests for aryl halides are difficult to obtain directly, and some of the best evidence for their presence involves indirect methods. Elemental analysis indicates the presence of halogen. If both the silver nitrate and sodium iodide-acetone tests are negative, the compound is most likely a vinyl or an aromatic halide, both of which are very unreactive toward silver nitrate and sodium iodide. Distinction between a vinyl and an aromatic halide can be made by means of the aluminum chloride-chloroform test. 

Attempts to carry out a similar sequence of reactions on j8-bromo-cyanolycopodine LIV were thwarted for a long time by the tendency of this compound to eliminate hydrogen bromide. Treatment with potassium acetate in methanol, amines, and other bases always led to the same nonketonic, very unreactive compound, which was eventually shown to be the enol ether LV 41). With silver acetate in benzene, however, LIV yielded a mixture of LV and an acetoxy compound in an approximate ratio of 3 1. Treatment of the acetate in the same sequence of reactions used in the a-series gave the carboxylic acid LVI. When LVI was treated with sodium borohydride and the acidified reaction mixture extracted into chloroform a neutral compound was isolated. In its IR-spectrum it had 1743 cm in Nujol which shifted to 1761 cm i in chloroform solution, but there was no absorption in the hydroxyl region. The IR-speetrum and the elemental analysis were in agreement with the lactone structure LVII. When this work was carried out, however, the IR-evidence alone was not sufficient to differentiate between a y- and a S-lactone ([Pg.331]

Similarly, [NbCl2lCp2] reacts with two equivalents of silver perchlorate in acetone22 to form [NbCl(Me2C0)2Cp2][C104]2. The compound has been isolated in the solid state and characterized by elemental analysis, as well as IR and NMR spectroscopies. Both 2,2 -bipyridyl and 1,10-phenanthroline readily displace the coordinated acetone molecules. 

Elemental composition Cu 64.18%, Cl 35.82%. Copper(I) chloride is dissolved in nitric acid, diluted appropriately and analyzed for copper by AA or ICP techniques or determined nondestructively by X-ray techniques (see Copper). For chloride analysis, a small amount of powdered material is dissolved in water and the aqueous solution titrated against a standard solution of silver nitrate using potassium chromate indicator. Alternatively, chloride ion in aqueous solution may be analyzed by ion chromatography or chloride ion-selective electrode. Although the compound is only sparingly soluble in water, detection limits in these analyses are in low ppm levels, and, therefore, dissolving 100 mg in a liter of water should be adequate to carry out aU analyses. 

Elemental composition P 20.20%, O 10.43%, Cl 69.36%. The compound is hydrolyzed in water and the products phosphoric and hydrochloric acids are measured by a colorimetric method for orthophosphate ion (see Phosphoric Acid, Analysis), and titration with silver nitrate for the chloride ion. Also, phosphate and chloride ions can be measured by ion chromatography. 

If the ratio be unity, the concentrations of the solute in each solvent will be the same if the ratio be far removed from unity, a correspondingly large proportion of the solute will be found in the one solvent which can be utilized to extract the Soln. from the other solvent. E.g. ether will remove ferric chloride from its aq. soln., and since many other chlorides are almost insoluble in ether, the process is utilized in analysis for the separation of iron from the other elements the solubility of cobalt thiocyanate in ether is utilized for the separation of cobalt perchromic acid is similarly separated from its aq. soln. by ether molten zinc extracts silver and gold from molten lead the extraction of organic compounds from aq. soln. by shaking out with ether or other solvent is much used in organic laboratories. 

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