Preparation

may be obtained as a dihydrate by evaporating an aqueous solution of molybdenum trioxide and sodium hydroxide. Heating the dihydrate at 100°C converts it to the anhydrous salt.

Definition

ChEBI: An inorganic sodium salt having molybdate as the counterion.

General Description

Sodium molybdate has corrosion resistant properties. On heating, it undergoes degradation and releases Na2O fumes.

Flammability and Explosibility

Nonflammable

Agricultural Uses

Sodium molybdate (NazMoO4-2H2O), which is an important molybdenum source, is applied along with other fertilizers or as a foliar spray (with 39% molybdenum). Sodium molybdate is the sodium salt of molybdic acid. Fusing molybdenum oxide with sodium carbonate or hydroxide makes sodium molybdate. Molybdenum is an essential component of the enzyme nitrate reductase which catalyzes the conversion of nitrate (NO3-) to nitrite (NO2-). It is also a component of the nitrogenase enzyme involved in nitrogen fixation by root nodule bacteria of leguminous crops. Soaking seeds in sodium molybdate solution (made with slurry or dust) before sowing is an effective seed treatment. Sodium molybdate, the most commonly used fertilizer supplying molybdenum, is used as foliar spray, or in mixed fertilizers. It is also used in seed treatment.

Biological Activity

sodium molybdate is an acid phosphatase inhibitor. the osteoclastic acid phosphatase isoenzyme, secreted by osteoclasts, is a member of a widely-distributed class of iron-containing proteins with acid phosphatase activity. elevated plasma isoenzyme levels are associated with increased bone turnover in metabolic disease. by inhibiting this class of acid phosphatases, sodium molybdate is capable of abolishing bone resorption. in addition, sodium molybdate has been shown to stabilize the nonactivated glucocorticoid-receptor complex.1. zaidi m, moonga b, moss dw, et al. inhibition of osteoclastic acid phosphatase abolishes bone resorption. biochemical and biophysical research communications, 1989, 159(1): 68-71.2. denis m, wikstr?m ac, gustafsson ja. the molybdate-stabilized nonactivated glucocorticoid receptor contains a dimer of mr 90,000 non-hormone-binding protein. journal of biological chemistry, 1987, 262(24): 11803-11806.

Safety Profile

Poison by intraperitoneal route. Moderately toxic by subcutaneous and intravenous routes. Experimental reproductive effects. Mutation data reported. When heated to decomposition it emits toxic fumes of Na2O. See also MOLYBDENUM COMPOUNDS.