Nitrates, inorganic, aqueous solution

Nitrates, inorganic, aqueous solution. 3218 35 Nitrocellulose, wet with not less than 2556 33... 

The application of CFD methods also makes it possible to carry out the analysis of such inorganic substances as anions and metals. As an example let us consider the analysis of trace amounts of nitrates in water. Tan [44] proposed a simple and sensitive method for determining nitrates in aqueous solutions using GC—mass spectrometry (MS) with an ionic detector-multiplier. The method is based on the nitration of 1,3,5-trimethoxy-benzene (TMB) in sulphuric acid. In this medium the nitration follows the hydrolysis of the ether groups of TMB, and nitrobenzene is formed as the final product [44]. The reaction mixture is analysed by GC and detected with a mass spectrometer. Hexamethyl-benzene (HMB) is used as an internal standard. To avoid interference from nitrates and chlorides, sulphamic acid and mercury(ll) sulphate are used. 

Nickel Catalyst, dry Nickel Cyanide Nickel Nitrate Nickel Nitrite Nicotine Nicotine Compound, liquid, n.o.s. 2881 1653 2725 2726 1654 3144 1655 37 53 35 35 55 55 Nitriles, toxic, n.o.s. (solid) Nitrites, inorganic, aqueous solutions, n.o.s. Nitrites, inorganic, n.o.s. Nitroanilines Nitroanisole 3276 3219 2627 1661 2730 55 35 35 55 55... 

Solution chemistry of inorganic precursors iescnhes the hydrolysis and condensation of aluminum salts such as nitrates in aqueous solution. 

Double Decomposition. In the double decomposition reaction, an inorganic metal salt such as a sulfate, chloride, acetate, or nitrate reacts with the sodium salt of the carboxyUc acid ia a hot aqueous solution. The metal soap precipitate is filtered, washed, dried, and milled. 

It is very common for inorganic chemists to neglect or ignore the presence of solvent molecules coordinated to a metal centre. In some cases, this is just carelessness, or laziness, as in the description of an aqueous solution of cobalt(ii) nitrate as containing Co ions. Except in very concentrated solutions, the actual solution species is [Co(H20)6] . In other cases, it is not always certain exactly what ligands remain coordinated to the metal ion in solution, or how many solvent molecules become coordinated. Solutions of iron(iii) chloride in water contain a mixture of complex ions containing a variety of chloride, water, hydroxide and oxide ligands. 

Inorganic extractions seem to have come into practical use without any great notice. Although Peligot in 1842 reported that uranyl nitrate could be recrystalhzed from ether, he never mentioned extraction of this salt from aqueous solutions. In textbooks after 1870, however, it is stated briefly that ether can even withdraw sublimate (HgCy from aqueous solution. It was also reported, for example, that cobalt thiocyanate is weakly extracted by ether, better by amyl alcohol, and even better by a mixture of both. 

Nitrocellulose, treated with different hydrolysing agents such as aqueous solutions of alkalis, does not yield cellulose and the corresponding metal nitrate, but a range of highly variable decomposition products of cellulose as well as of inorganic substances. 

Inorganic precursors are much cheaper and easier to handle than metal alkoxides. Therefore the industrial production of oxide powders for ceramics and catalysts is mainly based on the precipitation or coprecipitation of inorganic salts from aqueous solutions. Gibbsite, Al(OH)3, (see Aluminum Inorganic Chemistry) is precipitated from aluminate solutions. Ti02 powders are made via the controlled hydrolysis of titanium salts. Stabilized zirconia is coprecipitated from aqueous solutions of zirconium oxychloride, ZrOC, and yttrium nitrate, YlKOsjs. 

Where solubility alone is the issue, simply changing solvent to permit all species to be dissolved allows the chemistry to proceed essentially as it would in aqueous solution were species soluble. Typical molecular organic solvents used in place of water include other protic solvents such as alcohols (e.g. ethanol), and aprotic solvents such as ketones (e.g. acetone), amides (e.g. dimethylformamide), nitriles (e.g. acetonitrile) and sulfoxides (e.g. dimethylsulfoxide). Recently, solvents termed ionic liquids, which are purely ionic material that are liquid at or near room temperature, have been employed for synthesis typically, they consist of a large organic cation and an inorganic anion (e.g. lV, lV,-butyl(methyl)-imidazolium nitrate) and their ionic nature supports dissolution of, particularly, ionic complexes. 

In Inorganic Chemistry, typical spray reagents for cations include potassium iodine (0.2%, aqueous), hydrogen sulphide (saturated aqueous solution), ammonium sulphide (0.2 N, aqueous), quercetin (0.1%, alcoholic), l-(2-pyridylazo)-2-naphthol (PAN) (0.2%, methanolic), oxine (8-hydroxyquinoline) (1% methanolic, view under visible and UV light), and sodium rhodizonate (0.5%, aqueous). Reaction with dithizone to produce coloured dithizonate chelates of many metals is particularly suitable if quantitative spectrometric analysis (in situ or after elution) is to be carried out. Anions are detected with bromocresol purple (0.1%, alcoholic), 1% ammoniacal silver nitrate + 0.1% alcoholic fluorescein/UV light, zirconium alizarin lake (0.1% in HC1 solution), and ammonium molybdate (1%, aqueous) followed by SnCl2 (1%) and HC1 (10%). Typical detection limits range from 10 ng (10 9g) to several pg (10 6g). 

Many organic and inorganic compounds are oxidized by concentrated HNO3, although nitrate ion in aqueous solution is usually a very slow oxidizing agent (see above). Aqua regia contains free CI2 and ONCl and attacks Au (reaction 14.116) and Pt with the formation of chloro complexes. 

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