The gravimetric determination of tungsten in tungstate solutions

✍ Scribed by A. Claeys

• Publisher: Elsevier Science
• Year: 1957
• Tongue: English
• Weight: 597 KB
• Volume: 17
• Category: Article
• ISSN: 0003-2670
• DOI: 10.1016/s0003-2670(00)87047-6

✦ Synopsis

CRAVIMETRIC DETERMINATION

OF TUNGSTEN

Choice of the method

REFERENCE METHOD

This cholcc could not be determmcd by the spcclflc character of the reagent, but only by the quantltatlve formation of the precipltatc Thcrcfore, since the formation of insoluble WO, needs repeated treatment with acids for more or less total preclpltatlon, this method cannot bc used Obviously, the organic reagents tllat are to be tcstcd in this study must also be excluded as refercncc method .Ihe precipitation as Pb-, I3a-or Cd-tungstatem 1s difficult to USC, due to the unknown composltlon of the preclpitatc and the lack of an Ideal ignition temperature 31. On the other hand, the use of Hg2(K0,),, mtroduced by I~ERZELIUS~, 1s reported to give excellent results: it produces a quantitatlvc formation of Hg2M'0, by smgle precipitation and can be ignited to WO, as the stable lgmtlon form. Tius last method was chosen as reference method.

Experantcnfal .