Nitric acid, dilute

Nitric Acid, Dilute, i vol. of cone. HNO3 to 10 vols. of water. 

Nitric acid must be absent, for this is reduced to hydroxylamine and other compounds which react with permanganate. If nitric acid is present, evaporate the solution just to dryness, wash the sides of the vessel with about 3 mL of water, carefully add 3-4 mL of concentrated sulphuric acid, and evaporate until fumes of the latter are evolved. Repeat this operation twice to ensure complete removal of the nitric acid, dilute to 100 mL with water, add 5 mL of concentrated sulphuric acid, and proceed with the reduction. 

Surface contamination (lead and its compounds) Wiping of defined area surface using a moistened gauze pad digestion of sample using nitric acid dilution. ICP/AES GFAAS 2 pg/sample 0.1 pg/sample No data NIOSH 1994... 

Addition of ether to a nitration mixture (2-bromotoluene and cone, nitric acid) diluted with an equal volume of water in a separating funnel led to a low order explosion. This was attributed to oxidation of the ether (possibly containing alcohol) by the... 

Elemental composition Barium 54.21%, chromium 20.53%, oxygen 25.26%. The compound is digested in nitric acid, diluted, and analyzed for barium and chromium by flame- or fumace-AA or ICP-AES (see Barium and Chromium). Also, it may be characterized by x-ray diffraction, and the metal content determined by other x-ray techniques. 

Elemental composition Ca 50.03%, C 14.99%, N 34.98. A measured amount of the compound is hydrolyzed with water. The product CaCOs is filtered, dried and determined by gravimetry. Calcium carbonate or the parent calcium cyanamide may be digested with nitric acid, diluted appropriately, and analyzed for Ca by AA or ICP spectroscopy. The hydrolysis product in solution, ammonia, may be measured by ammonium ion selective electrode, or by colorimetry followed by Nesslerization. 

Cerium may be analyzed in solution by AA or ICP techniques. The metal or its compounds are digested in nitric acid, diluted appropriately prior to analysis. Also, it may be measured by ICP/MS at a still lower detection level (low ppt). The metal may be analyzed nondestructively by x-ray techniques. 

Elemental composition Ce 42.18%, S 19.30%, O 38.53%. It is digested with nitric acid, diluted appropriately and analyzed for Ce by AA or ICP spectroscopy (see Cerium). The compound may be dissolved in small quantities of water (forms a basic salt when treated with large a volume of water). The solution is analyzed for sulfate ion by gravimetry following precipitation with barium chloride. Alternatively, the compound is dissolved in hot nitric acid and the solution analyzed for sulfate by ion-chromatography. 

Elemental composition Co 32.47%, C 28.10%, O 37.43%. Cobalt octacarbonyl may be digested with nitric acid, diluted appropriately, and analyzed by AA, ICP, or other instrumental methods (see Cobalt). The compound may be dissolved in methanol and the solution analyzed by GC/MS. 

Elemental composition Cu 34.98%, C 26.45%, H 3.33%, O 35.24%. Copper(II) acetate is digested with nitric acid, diluted appropriately and analyzed for copper by various instrumental techniques (see Copper). 

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 (neutral CuCr04) Cu 35.39%, Cr 28.97%, 0 35.64%. These chromates are analyzed hy x-ray, thermogravimetic analysis (the basic form loses water around 260°C) and metal analysis. Copper and chromium may he analyzed hy digesting the compound(s) with nitric acid, diluting appropriately with water, followed hy AA, ICP, or other instrumental analysis, (see Chromium and Copper). 

Elemental composition Gd 86.76%, O 13.24%. A weighted amount of compound is dissolved in nitric acid, diluted, and analyzed by AA or ICP technique. The solid powder may be characterized nondestructively by x-ray methods. 

Elemental composition Ga 48.20%, As 51.80%. Both As and Ga may be analyzed by various instrumental techniques including flame and furnace AA, ICP spectrometry, and x-ray methods. A weighed amount of sohd material is digested with nitric acid, diluted in water and analyzed for these metals. The crystals may be characterized nondestructively by their optical and electronic properties. 

The metal or its compounds may be digested with nitric acid, diluted appro-... 

Germanium hydrides are decomposed by nitric acid, diluted with water, and analyzed for metalic Ge (See Germanium). Monogermane is identified by GC/MS. 

Elemental composition In 82.71%, 0 17.29%. Indium trioxide may be digested with nitric acid, diluted appropriately and analyzed for indium by AA or ICP. It may be identified by x-ray diffraction. The oxide may be heated with excess hydrogen and water formed may be analyzed quantitatively by gravimetry or the Karl-Fisher method. 

Elemental composition Fe 77.73%, 0 22.27%. The oxide maybe characterized by x-ray methods. The metal may be determined by dissolving the compound in dilute nitric acid, diluting the extract appropriately and analyzing... 

Elemental composition Pb 77.54%, C 4.49%, O 17.96%. The compound is digested with nitric acid, diluted and analyzed for lead by various instrumental techniques (See Lead). Carbonate may be tested by treating the compound with dilute HCl. It will effervesce, the evolved CO2 gas will turn hmewater milky. Also, liberated CO2 can be identified using a GC-equipped with a TCD or by GC/MS. The characteristic mass ion for GC/MS identification of CO2 is 44. 

Elemental composition Pb 90.40%, H 0.29%, O 9.30%. The hydroxide is digested with nitric acid, diluted and analyzed for lead by AA, ICP or other instrumental technique (See Lead). A weighed amount of the salt is heated in an oven at 145°C and water lost is measured by gravimetry. The residue lead monoxide also may be analyzed by x-ray, or its lead content can be measured by various instrumental methods. 

Elemental composition Pb 59.37%, Cl 40.63%. The compound is hydrolyzed in water to Pb02, which is separated, digested with nitric acid, diluted, and analyzed for lead. The aqueous solution containing the hydrolysis product HCl is determined by acid-base titration. The chloride ion is measured by an electrode or ion chromatography, or by titration with a standard solution of... 

Elemental composition Mn 28.17%, C 30.80%, 0 41.03%. The compound is cautiously digested with nitric acid, diluted and analyzed for manganese hy instrumental techniques. Its solution in an organic solvent may be analyzed... 

Molybdenum may be identified at trace concentrations by flame atomic absorption spectrometry using nitrous oxide-acetylene flame. The metal is digested with nitric acid, diluted and analyzed. Aqueous solution of its compounds alternatively may be chelated with 8—hydroxyquinobne, extracted with methyl isobutyl ketone, and analyzed as above. The metal in solution may also be analyzed by ICP/AES at wavelengths 202.03 or 203.84 nm. Other instrumental techniques to measure molybdenum at trace concentrations include x-ray fluorescence, x-ray diffraction, neutron activation, and ICP-mass spectrometry, this last being most sensitive. 

Elemental composition Ni 63.32%, H 2.17%, O 34.51%. The hydroxide may be digested with nitric acid, diluted appropriately, and analyzed for nickel by various instrumental methods (See Nickel). Also, water content may be measured by TGA or DTA method after decomposing the hydroxide at 230°C. The residue NiO may be characterized by x-ray and other methods (See Nickel Oxide). 

Elemental composition Ag 65.03%, Cr 15.68%, 0 19.29%. The salt is dissolved in nitric acid, diluted, and analyzed for silver and chromium by flame-and furnace-AA, ICP-AES or other instrumental method to measure the contents of these metals. 

Elemental composition Ag 45.95%, I 54.05%. The salt is dissolved in hot concentrated nitric acid, diluted appropriately with water and analyzed for silver. 

Elemental composition Ta 81.89%, O 18.11%. The oxide may be identified by x-ray methods. It may be dissolved in hydrofluoric and nitric acid, diluted and analyzed by AA, ICP and other instrumental techniques. 

Elemental composition T185.22%, Cl 14.78%. A smaU amount of the salt is dissolved in water (it is shghtly soluble in water at room temperature) and the solution analyzed for chloride ion by ion chromatography or by titration with a standard solution of silver nitrate using potassium chromate indicator. The salt is digested with nitric acid, diluted, and analyzed for thallium metal by... 

Elemental composition Zn 80.34%, 0 19.66%. The oxide is characterized by x-ray diffraction. Zinc content may be measured by dissolving the oxide in nitric acid, diluting and analyzing by AA or ICP (see Zinc). 

H0.CH2CH2.N(N0).C( NH).NH.N02 mw 177. 13, N 39.54% yel crysts (from MeOH), mp 111.5° (dec), unstable compd which decomposed on standing in the dark for 7 days was obtd when j3-Hydroxyethylnitroguanidine was dissolved in 70% nitric acid, diluted with water Na... 

A. Connell (1802) 140 obtained a white precipitate—ferrous iodate—by boiling a soln. of iron in iodic acid, and C. F. Rammelsberg found that the addition of potassium iodate to ferrous sulphate gives a yellowish-white precipitate which is decomposed when heated. It is sparingly soluble in nitric acid, and it dissolves in an excess of ferrous sulphate, and the soln., when heated, precipitates basic ferric iodate. A. Ditte mixed boiling soln. of a ferric salt and an alkali iodate and obtained a brown precipitate—ferric iodate—insoluble in hot nitric acid diluted with its own volume of water. Crystals can be obtained by mixing warm dil. soln. of ferric nitrate, acidified with nitric acid, and sodium iodate. The precipitate... 

As a preliminary, ferric sulfate is made by the oxidation of ferrous sulfate. Dissolve 100 g. of ferrous sulfate in 100 cc. of boiling water, to which has been added before heating 10 cc. of sulfuric acid. Add concentrated nitric acid portionwise to the hot solution, until a diluted sample gives a reddish-brown (not black) precipitate with ammonia. This will require about 25 cc. Boil the solution down to a viscous liquid to get rid of excess nitric acid, dilute to about 400 cc., and add the calculated weight of ammonium sulfate. The crystallization is conducted as in the former exercise, preferably under 20°. By the addition of potassium sulfate, the corresponding potassium iron alum may be secured. In this case, it is necessary to concentrate the solution until there is about four parts of water to one of the hydrated alum and cool to about zero to secure crystallization. Both of these alums are amethyst in color, the potassium salt being much less stable and having a rather low transition point. 

A third method Is to hoat tho metal for several hours. to 130°, with a small quantity of commercial nitric acid diluted with twice its volume of pure water. The foreign metals being more easily oxidised than the mercury, are dissolved, and this operation having been repeated as often as required, the purified metal is then washed and dried. "... 

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