Hexahydrate

Forms hexahydrate. nickel nitrate, Ni(N03)2,6H20. Green... 

The hexahydrate fonns colourless crystals, m.p. 44 C (104 C when anhydrous), b.p. 126 C. Made by the action of alcoholic ammonia on 1,2-dichloroethane, piperazine is used in human and veterinary medicine in the treatment of threadworm and roundworm infestations. 

Nickel forms yellow anhydrous halides NiXjlX = F. Cl. Br) and a black iodide Nil2 all these halides are made by direct combination of the elements, and the chloride by reaction of sulphur dichloride oxide with the hydrated salt. All dissolve in water to give green solutions from which the hydrates can be crystallised the solutions contain the ion [NifHjOls], and the chloride crystallises as NiCl2.6H2O, nickel(II) chloride hexahydrate. 

Mannitol, CH,0H(CH0Hi4CH40H, is a hexahydric alcohol obtained by the reduction of mannose. Since ring formation does not occur in mannitol, the hexacetyl derivative can exist in only one form, and therefore either zinc chloride or sodium acetate can be used as a catalyst for the acetylation. 

Add about 60 ml. of petroleum (b.p, 60-80°) with stirring to the fraction of b,p, 150-180°, thus precipitating the pure anhydrous pinacol (2 5-3 8 ) Filter this off, and then shake the filtrate with ca. 4 ml, of water the remaining pinacol now separates as the hexahydrate (5 g.). The two crops may be united and recrystallised from ca. 10 ml, of water (total yield of hexahydrate, 8-9 g,). Dry and bottle the product rapidly as described in (a). 

Both forms sublime very readily, even at room temperature a small sample on exposure to the air will completely volatilise in a short time, particularly on a warm day or if the sample is exposed to a gentle current of air. Hence the above method for rapid drying. A sample confined in an atmospheric desiccator over calcium chloride rapidly disappears as the vapour is adsorbed by the calcium chloride. A sample of the hexahydrate similarly confined over sodium hydroxide undergoes steady dehydration with initial liquefaction, for the m.p. of the hydrated-anhydrous mixture is below room temperature as the dehydration proceeds to completion, complete resolidification occurs. 

Required Pinacol hexahydrate, 10 g. concentrated sulphuric acid, 15 ml. (28 g.). 

Pinacol possesses the unusual property of forming a crystalline hexahydrate, m.p. 45°, and the pinacol is separated in this form from the unreacted acetone and the tsopropyl alcohol. The magnciaium is conveniently amalgamated by dissolving mercuric chloride in a portion of the acetone mercury is then liberated by the reaction ... 

Iron(II) ammonium sulfate hexahydrate, Q.IN Le(II) to Le(III). Dissolve 39.2139 g of LeS04 2(NH4)2S04 hHjO in 500 mL of IN sulfuric acid and dilute to 1 L. If desired, check against standard dichromate or permanganate solution. 

LED precursors MGHT GENERATION - LIGHT-EMITTING DIODES] (Vol 15) Arsine hexahydrate [65423-90-7]... 

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