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Reagent sodium molybdate

Froehde s reagent (gives characteristic colorations with certain alkaloids and glycosides) dissolve 0.01 g of sodium molybdate in 1 mL of concentrated H2SO4 use only a freshly prepared solution. [Pg.1191]

Discussion. When a solution of an orthophosphate is treated with a large excess of ammonium molybdate solution in the presence of nitric acid at a temperature of 20-45 °C, a precipitate is obtained, which after washing is converted into ammonium molybdophosphate with the composition (NH4)3[P04,12Mo03]. This may be titrated with standard sodium hydroxide solution using phenolph-thalein as indicator, but the end point is rather poor due to the liberation of ammonia. If, however, the ammonium molybdate is replaced by a reagent containing sodium molybdate and quinoline, then quinoline molybdophosphate is precipitated which can be isolated and titrated with standard sodium hydroxide ... [Pg.304]

The reagent can be used, for example, on aluminium oxide, silica gel, kieselguhr. Si 50000, RP and cellulose layers. Sodium molybdate-impregnated phases and zirconium oxide layers are also suitable [1]. [Pg.138]

Reagents and conditions were 2 ml. cumene hydroperoxide (82% purity), 2 ml. olefin, 1 ml. methanol, and 0.05 gram sodium molybdate in a sealed tube for 5 hr. at 101 °C. [Pg.423]

Dissolve 100 g of sodium tungstate Rand 25 g of sodium molybdate R in 700 mL of water. Add 100 mL of hydrochloric add R and 50 mLof phosphoric acid R, Heat the mixture under a reflux condenser in a glass apparatus for 10 h. Add 150 % of lithium sulfate R. 50 mL of water, and a few drops of bromine R, Boil to remove the excess of bromine (15 min), cool, dilute to 1000 mL with water, and filler The reagent should be yellow in color. If it requires a greenish tint, it is... [Pg.358]

Reagent. Stock Solution, Dissolve 100 g of sodium tungstate and 25 g of sodium molybdate in 800 ml of water in a 1500-ml flask, add 50 ml ofphosphoric acid and 100 ml of hydrochloric acid, and reflux for 10 hours. Cool, add 150 g of lithium sulphate, 50 ml of water, and 4 to 6 drops of bromine, and allow to stand for 2 hours. Boil for 15 minutes to remove the excess of bromine, cool, filter, and dilute to 1000 ml with water. [Pg.133]

High selectivities are also obtained by combining ion-exclusion chromatography with photometric detection after derivatization of the column effluent with suitable reagents. As a typical example, Fig. 4-6 shows the chromatogram of a 20-ppm silicate standard obtained by derivatization with sodium molybdate in acid solution and subsequent photometric detection at 410 nm. Orthophosphate may also be detected under these conditions. Because of its different acid strength it elutes prior to silicate, so that this method is very selective for the determination of both anions. [Pg.218]

CCRIS 3682 Disodium molybdate dihydrate Molybdic acid, disodium salt, dihydrate Molyhibit 100 Sodium molybdate Sodium molybdate dihydrate Sodium molybdate(VI) dihydrate Anhydrous sodium molybdate [77631-95-0]. Reagent in analytical chemistry, used in manufacture of paint pigment, corrosion inhibitor, catalyst in dye and pigment production, additive for fertilizers and feeds, micronutrient. Crystalline powder dec 100° soluble in H2O (60 g/100 ml). AAA Molybdenum Cerac Climax Molybdenum Co. Mallinckrodt Ino. PMC. [Pg.570]

The phase-transfer-assisted permanganate oxidation of alkynes and alkenes has been reviewed. Terminal and internal alkynes are oxidized to 1,2-dicarbonyl compounds by the combined action of diphenyl disulphide, ammonium peroxidisulphate and water or by sodium periodate in the presence of ruthenium dioxide (equation 34). Other reagents for the conversion of acetylenes into 1,2-dicarbonyl compounds are hydrogen peroxide in the presence of (2,6-dicarboxylatopyridine)iron(II), the complex oxo(A, A -ethylenebissalicylideneiminato)chromium(V) trifluoromethanesulphonate (216)and ruthenium tetroxide as a mediator in electrooxidation. l-Acetoxyalkan-2-ones 217 are obtained by the oxidation of terminal acetylenes with sodium perborate and mercury(II) acetate in acetic acid ". Terminal alkynes give a-ketoaldehydes 218 on treatment with dilute hydrogen peroxide, combined with mercury(II) acetate and sodium molybdate or sodium tungstate under phase-transfer conditions. ... [Pg.314]

Sulfomolyhdic acid (Froehde s reagent for alkaloids and glucosides). Dissolve 10 g of molybdic acid or sodium molybdate in 100 mLof cone. H2SO4. [Pg.1199]

Froehde s tast A presumptive test for opioids. Froehde s reagent consists of 0.5 gram of sodium molybdate (Na2Mo04) dissolved in 100 ml of concentrated sulphuric acid. Opioids give a pink to purple colour. [Pg.335]

Salicylic acid Sodium molybdate anhydrous Sodium molybdate dIhydrate Sodium phosphate dibasic anhydrous Sulfanilic acid Tannic acid Thallium (I) sulfate reagent, analytical alcohol identification... [Pg.5596]

Molybdate reagent (flow-analysis) 7 g of sodium molybdate dihydrate, Na2Mo04 2H2O, and 21 mL of sulphuric acid (reagent 1) are dissolved and made up to 1L with pure water. [Pg.195]

Reagent solution Dianisidine molybdate solution A solution of 0.26 g diani-sidine in 1 ml concentrated sulfuric acid is added drop by drop and with swirling to a solution of 2.6 g of sodium molybdate in 20 ml of 7.6 % sulfuric add. The mixture is allowed to stand for 12 hours and then filtered if need be. [Pg.391]

Reagent 10 g of sodium molybdate are dissolved in a mixture of 25 ml of water and 10 ml of cone, nitric acid. 1.4 ml of quinoline are dissolved in a mixture of 15 ml of water, 7 ml of cone, hydrochloric acid and 6 ml of cone, nitric acid. The two solutions are mixed with stirring and 60 ml of water are added. The filtered solution is stable for at least four weeks. Filter paper is moistened with the reagent and dried at 60-70 C. [Pg.391]


See other pages where Reagent sodium molybdate is mentioned: [Pg.305]    [Pg.392]    [Pg.347]    [Pg.209]    [Pg.37]    [Pg.707]    [Pg.1039]    [Pg.182]    [Pg.23]    [Pg.77]    [Pg.78]    [Pg.103]    [Pg.3]    [Pg.384]    [Pg.990]    [Pg.360]    [Pg.150]    [Pg.360]    [Pg.77]    [Pg.78]    [Pg.4512]    [Pg.1117]    [Pg.1120]    [Pg.1122]    [Pg.653]    [Pg.45]    [Pg.37]   
See also in sourсe #XX -- [ Pg.2 , Pg.2 , Pg.550 , Pg.799 ]




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