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. 

Molybdenum. The commonly used molybdenum materials are sodium molybdate [7631-95-0] ammonium molybdate [12027-67-7] molybdenum trioxide [1313-27-5] molybdenum sulfate [51016-80-9] and frits. Molybdenum is used in smaller amounts than any of the other micronutrients, ranging from a few grams to 3 kg/hm of Mo. 

Oxidation. Maleic and fumaric acids are oxidized in aqueous solution by ozone [10028-15-6] (qv) (85). Products of the reaction include glyoxyhc acid [298-12-4], oxalic acid [144-62-7], and formic acid [64-18-6], Catalytic oxidation of aqueous maleic acid occurs with hydrogen peroxide [7722-84-1] in the presence of sodium tungstate(VI) [13472-45-2] (86) and sodium molybdate(VI) [7631-95-0] (87). Both catalyst systems avoid formation of tartaric acid [133-37-9] and produce i j -epoxysuccinic acid [16533-72-5] at pH values above 5. The reaction of maleic anhydride and hydrogen peroxide in an inert solvent (methylene chloride [75-09-2]) gives permaleic acid [4565-24-6], HOOC—CH=CH—CO H (88) which is useful in Baeyer-ViUiger reactions. Both maleate and fumarate [142-42-7] are hydroxylated to tartaric acid using an osmium tetroxide [20816-12-0]/io 2LX.e [15454-31 -6] catalyst system (89). 

Absorption-type refrigerators operating with strong lithium bromide solutions can also be inhibited by a number of chemicals. Thus, a mixture of lithium hydroxide -I- BTA -I- sodium molybdate has been reported . 

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 ... 

Solutions required. Sodium molybdate solution. Prepare a 15 per cent solution of sodium molybdate, Na2Mo04,2H20. Store in a polythene bottle. 

The use of molybdenum catalysts in combination with hydrogen peroxide is not so common. Nevertheless, there are a number of systems in which molybdates have been employed for the activation of hydrogen peroxide. A catalytic amount of sodium molybdate in combination with monodentate ligands (e.g., hexaalkyl phosphorus triamides or pyridine-N-oxides), and sulfuric acid allowed the epoxidation of simple linear or cyclic olefins [46]. The selectivity obtained by this method was quite low, and significant amounts of diol were formed, even though highly concentrated hydrogen peroxide (>70%) was employed. 

Typically, molybdate-based formulations are liquids having approximately 10% sodium molybdate (Na2Mo04 2H20) combined with either a lower percentage of silicate or a higher percentage of nitrite. Sodium molybdate is commercially available as a 41% solution or 100% crystalline powder. Potassium molybdate (K2Mo04) is also available. 

Sodium hexakis(formato)molybdate, 3, 1235 Sodium hypochlorite alkene epoxidation manganese catalysts, 6,378 Sodium ions biology, 6, 559 selective binding biology, 6, 551 Sodium molybdate, 3, 1230 Sodium peroxoborate, 3,101 Sodium/potassium ATPase, 6, 555 vanadate inhibition, 3, 567 Sodium pump, 6, 555 mechanism, 6, 556 Sodium pyroantimonate, 3, 265 Sodium salts... 

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]. 

Silica gel G impregnated with 0.3-M aqueous sodium molybdate Silica gel G... 

Sodium molybdate (Basic form of components for pigments fertilizers and other molybdenum salts... 

Flora SJS, Jeevaratnam K, Kumar D. 1993. Preventive effects of sodium molybdate in lead intoxication in rats. Ecotoxicol Environ Safety 26 133-137. 

In the preparation of a dyestuff from aniline, nitrobenzene (as oxidant), hydrochloric acid and sodium hydroxide, ferric chloride is often used as catalyst, but sodium molybdate was substituted as a more effective catalyst. The materials were charged into a 4.5 m3 reactor and heating was started after addition of nitrobenzene, but the temperature controller was mis-set, and overheating at a high rate ensued. The exotherm was much higher than normal because of the more effective catalyst, and partial failure of the cooling water led to an uncontrollable exotherm. 

Olas and Wachowicz (2002) investigated the effects of tranx-resveratrol and vitamin C on oxidative stress in blood platelets. The level of 02 in control blood platelets and platelets incubated with resveratrol or vitamin C was recorded using a chemiluminescence method. On the other hand, Oh and others (2006) reported the x02 quenching activities of various freshly squeezed fruit and vegetable juices by measuring their inhibitory effects on the rubrene oxidation induced by x02 from disproportionation of hydrogen peroxide by sodium molybdate in a microemulsion system. 

Sodium molybdate and other molybdenum compounds in toxic baits have potential for termite control (Brill et al. 1987). Baits containing 1000 mg Mo/kg were fatal to 99% of the termite Reticu-litermes flavipes in 48 days. After 8 to 10 days, termites became steel-gray in color, but appeared otherwise normal. Mortality began only after day 16. Termites did not avoid the poisoned bait, even at concentrations of 5000 mg Mo/kg. Yoshimura et al. (1987) reported similar results with another species of termite sodium molybdate killed 100% of the workers in a colony of Copotermes formo-sanus within 24 h after eating filter paper treated with a 5% solution. Some other species of insects — including fire ants (Solenopsis sp.) and various species of beetles and cockroaches — were not affected when exposed to baits containing 5000 mg Mo/kg for 48 days (Brill et al. 1987). 

FISH Flannelmouth sucker, Catostomus latipinnis larvae age 12-13 days molybdenum as sodium molybdate >2800 mg Mo/L LC50 (48 h) 15... 

Juveniles exposed to 193 pg Mo/L, as sodium molybdate, for 90 days No accumulation whole-body content of <0.7 mg Mo/kg DW 14... 

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