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|Section2= |Section7= |Section8= }} Ammonium heptamolybdate is an odourless crystalline compound ranging in colour from white to yellow-green. It is usually encountered as the tetrahydrate, whose chemical formula is (NH4)6Mo7O24·4H2O. It is often referred to as ammonium paramolybdate or simply as ammonium molybdate, although ammonium molybdate can also refer to ammonium orthomolybdate, (NH4)2MoO4, and several other compounds. == Synthesis == Ammonium heptamolybdate is easily prepared by dissolving molybdenum trioxide in an excess of aqueous ammonia and evaporating the solution at room temperature. While the solution evaporates, the excess of ammonia escapes. This method results in the formation of six-sided transparent prisms of the tetrahydrate of ammonium heptamolybdate.〔L. Svanberg & H. Struve, ''J. pr. Ch.'' 44 (), p. 282; cited in ''Gmelin's Handbuch für Anorganische Chemie'', ''53'', p. 255.〕 Solutions of ammonium paramolybdate react with acids to form molybdic acid and an ammonium salt. The pH value of a concentrated solution will lie between 5 and 6. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Ammonium heptamolybdate」の詳細全文を読む スポンサード リンク
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