Yellow hydrate

Siher I) fluoride, AgF, is prepared by evaporation of a solution of excess Ag20 in HF after filtration or by heating anhydrous AgBF. The anhydrous salt is yellow hydrates are known, It is very soluble in water and in many organic solvents. Used as a mild fluorinating agent. On treatment of a solution with Ag a sub-fluoride, Ag2F, is formed. 

The product is a solid yellow hydrated oxide. If prepared by a method in the absence of water, a black anhydrous product is obtained. Germanium(II) oxide is stable in air at room temperature but is readily oxidised when heated in air or when treated at room temperature with, for example, nitric acid, hydrogen peroxide, or potassium manganate(VII). When heated in the absence of air it disproportionates at 800 K ... 

The yellow hydrated oxide is slightly acidic and forms germanates(II) (germanites). The increased stability of germanium(II) oxide compared to silicon(II) oxide clearly indicates the more metallic nature of germanium. 

Mercurous Nitrate. Mercurous nitrate [10415-75-5] Hg2N20 or Hg2(N02)2, is a white monoclinic crystalline compound that is not very soluble in water but hydrolyzes to form a basic, yellow hydrate. This material is, however, soluble in cold, dilute nitric acid, and a solution is used as starting material for other water-insoluble mercurous salts. Mercurous nitrate is difficult to obtain in the pure state directly because some mercuric nitrate formation is almost unavoidable. When mercury is dissolved in hot dilute nitric acid, technical mercurous nitrate crystallizes on cooling. The use of excess mercury is helpful in reducing mercuric content, but an additional separation step is necessary. More concentrated nitric acid solutions should be avoided because these oxidize the mercurous to mercuric salt. Reagent-grade material is obtained by recrystaUization from dilute nitric acid in the presence of excess mercury. 

The most stable solid hypochlorites are those of Li, Ca, Sr and Ba (see below). NaOCl has only poor stability and cannot be isolated pure KOCl is known only in solution, Mg yields a basic hypochlorite and impure Ag and Zn hypochlorites have been reported. Hydrated salts are also known. Solid, yellow, hydrated hypobromites Na0Br.xH20 (x = 5, 7) and K0Br.3H20 can be crystallized from solutions obtained by adding Br2 to cold cone solutions of MOH but the compounds decompose above 0°C. No solid metal hypoiodites have yet been isolated. 

When heated at 700°C the yellow hydrated pentoxide converts to an anhydrous white solid with a formula Sh20i3 containing both Sb(lII) and Sb(V). Heating at 900°C produces a white insoluble powder of Sb02 of both a and P forms. The p form consists of Sb(V) in octahedral interstices and pyramidal Sb(lII)04 units. 

F. Martin gave 174° for the temp, of explosion. According to L. Wohler and W. Krupko, basic cupric azide, cupric oxyazide, CuO.CuNg, is formed as a yellow hydrated substance when water with normal cupric azide in suspension is heated to 70°-80° in a current of air freed from carbon dioxide until the calculated quantity of hydrazoic acid has been evolved. It inflames at 245°. L. M. Dennis and H. Isham obtained cupric amminoazide,Cu(NHg)Ns,by shaking freshly precipitated black cupric hydroxide, while still moist, with an excess of hydrazoic acid and washed the precipitate. A soln. of the precipitate in aq. ammonia deposits crystals of the salt. It explodes when heated or struck. It is insoluble in water, and soluble in dil. acids,... 

Potassium Cobaltous Nitrite, 2KN02.Co(N02)2. H20, is obtained by adding potassium nitrite to a neutral solution of cobalt chloride. It is precipitated as a yellow, hydrated mass, which is soluble in hot water to a red solution.6... 

The yellow hydrate dissolves ver slightly in water the specific conducthity of the saturated solution at 25" C. is /c=10-3xl0 . 

Germanium monoxide is prepared by dehydration of the yellow hydrate, obtained by reaction of GeCl2 with aqueous NH3, or by heating Ge(OH)2, obtained from GeCl2 and water. The monoxide, which is amphoteric, is not as well characterized as Ge02, and disproportionates at high temperature (equation 13.60). 

Yellow hydrated needles from water or dil ale. Slightly bitter, astringent taste. The water of crystn (about 3 mols) is removed at 130 and 0.2 mm Hg. The anhydr substance, mp 205 (rapid heating). Sparingly sol in cold water freely sol in hot water, hot alcohol practically insol in ether. Alkaline solns are sulfur-yellow and nn dilution show characterisitic blue-greeu fluorescence. 

Deep-red triclinlc crystals decompose readily when stored damp. Water content 28 moles of HsO/mole. Quite soluble in HsO. A yellow hydrate containing more water also exists. 

Mirabilite A soluble, white or yellow, hydrated sodium sulfate evaporitic mineral Na2S04 IOH2O. 

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