Notes for students in chemistry : being a syllabus of chemistry compiled mainly from the manuals of Fownes-Watts, Miller, Wurz, and Schorlemmer / by Albert James Bernays.

Albert Bernays

Date:: 1878

Credit: Notes for students in chemistry : being a syllabus of chemistry compiled mainly from the manuals of Fownes-Watts, Miller, Wurz, and Schorlemmer / by Albert James Bernays. Source: Wellcome Collection.

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$Sjnnbol. At. weight. Sp. gr. Molybdenum. .Mo = 96 .. 8.62 Wolframium . . W = 184 .. 17.60 [XXIX. Molybdenum Mo = 96. Dyad, tetrad and psoudo-triad, never native. White, brittle, very infusible metal. S]j. gr. 8.62. Name from fj.o\v05atva a piece of lead, which its ore Molybdenite resemble.s. By roasting in air, S^Mo or Molybdio sulphide, becomes Molybdic anhydride M0O3, and this is reduced by charcoal in a smith's forge in a crucible lined with charcoal. Three oxides : two basic. Molybdous oxide MoO, black. By action of H., (Zn and 2CIH, and CIH) upon a molybdate : reduced to MoCl„ and precipitated as hydroxide by HOK. When heated in air, burns to Molybdic oxide MoOo. Is deep-brown, and insoluble in acids. Its hydrox- ide dissolves readily to red solutions. From M0O3 hj reducing agents. By NO^OH into Molybdic anhydride M0O3 = 144- White crystalline powder, slightly soluble in water. As acid, not known ii) free state. Molybdate of lead MoO^Pb, native, in yel- low quadratic plates. Mo02(OH.,N),, in colorless, .square prisms. Solution used to detect traces of ortho-phosphoric sicid ; suspected liquid acidulated with NO„OH, and molybdate added. The liquid becomes yellow, and on boiling, deposits yellow ci-ystalliue precipitate of phosphoric and molybdic acids, combined with HsNCs per cent. P,0,). Sulphides. MoS„. M0S3. M0S4. Chlorides. MoCl^. MOjClc. M0CI4. M0CI5. Mo„Cle heated in absence of ail- into yellow MoCl, and brown MoClj. M0CI5 by heating Mo in a sti-eam of Chlorine, and this in a stream of H into MoX'lj. Molybdenum is estimated as S2M0: contains 60 per cent, of Mo.] [XXX. Wolfram, or Tungsten W = 184. Tetrad and hexad metal, never native. Iron-grey metal of sp. gr. I 7.6. Burns, when heated, into WO3. From WO3 by charcoal in a smith's forge. Oxides. Tungstic dioxide A\'0„, not ba.sic. As a brown powder by heating WU3 with H„. Tungstic anhydride WO3 = 232. Forms Tungstic acid \VO,(OH)2.0H2 and Metatungstic acid W,0,,(UH)„. WO3 sti-aw-yellow powder. From Scheelite WO^Ca by NO._,OH. The common mineral, Wolfram, is W0^Mn,3W0^Fe. ■ So- mvM TUNGSTATE IS sometimcs added to starcli to render stiffened fabrics incombustible. Chlorides. WCl^ and WCl^ are volatile. Sulphides S,,W, bluisli-black needles. S^W a powerful sulphur- acid. Sulpho-tungstates. Thus: S^WK.,. Tungsten is weighed as WO3 : contains 79.31 per cent, of W.]$