Salt sublimation

Cupric nitrate (3H2O) [10031-43-3 (3H2O) 3251-23-8 (anhydr)] M 241.6, m 114 , b 170 (dec), d 2.0. Crystd from weak aqueous HNO3 (0.5mL/g) by cooling from room temperature. The anhydrous salt can be prepared by dissolving copper metal in a 1 1 mixture of liquid NO2 and ethyl acetate and purified by sublimation [Evans et al. J Chem Soc, Faraday Trans 1 75 1023 1979], The hexahydrate dehydr to trihydrate at 26°, and the anhydrous salt sublimes between 150 and 225°, but melts at 255-256° and is deliquescent. 

Determination of the influence of crystal structure and reactant environment on deammination and dehydration processes is complicated by the several solid phase transformations that are a characteristic feature of many ammonium salts. Sublimation and/or melting may also occur. Deammination and dehydration steps are generally reversible. At high temperatures, however, particularly in the presence of a residual oxide... 

How can the different nature of thermal decomposition of ammonium salts be explained What ammonium salts sublime How can one prove experimentally that the salts used are ammonium ones ... 

The lower tube outlet temperature promotes higher rates of salt sublimation from vapor to a corrosive fouling solid. 

In this Menstruum, we make use of the salt ammonium chloride (NH4CI) or Sal Ammoniac. All of the volatile ammonium salts are valuable in alchemy and not just minerals, but plants and animals contain Sal Ammoniac. These salts sublime easily, and if not captured, will vapour away unseen. 

The decomposition of the nitrite in aqueous solution has been the subject of many investigations.7 In vacuum at 37° to 40° C. the decomposition is very slight at 70° C. it proceeds slowly in accordance with the equation, but most of the salt sublimes unchanged. When the sublimate is heated with a naked flame, it yields nitrogen and up to 6 per cent, of nitric oxide.8... 

Heating of the ammonium salts shifts the formation equilibrium to the ammonia side, the ammonium salts sublime under dissociation. Ammonium salts with oxidizing anions (N02, N03, Cr207 ) decompose under oxidation of the ammonium nitrogen to N2 or N2O. 

A common feature of the decompositions of many ammonium compounds is the identification of the first step in reaction as proton transfer. The consequent accumulation of protons with the residual oxy-anions may be followed by the elimination of water, accompanied by condensation (or continued condensation) of the anions, see chromates and phosphates above, ultimately leading to residual oxide formation. Alternatively the acid may be volatilized, many ammonium salts sublime... 

The chymical artists of the seventeenth century were essentially practical workers, with little interest in theory. Their theoretical views, in so far as they concerned themselves with such superfluities, were easily reconciled with the current notions. Their numerous distillations of plant and animal materials gave them phlegm and oU (aqueous and oily distillates), salt (sublimed matter), earth (residue), and spirit or air (vapour or gas) and these products were easily fitted into the pattern of the Aristotelian quartette and the Paraccisian iria prima. 

Zirconium acetylacetonate 10-hydrate effloresces in air and may be completely dehydrated in a vacuum of 0.1 mm. The anhydrous salt sublimes slowly with some decomposition in vacuo at about 140° and melts at 194.5 to 195° with decomposition. The acetylacetonate reacts with alcohol. Its solubility at 25° per liter in other organic solvents is as follows carbon disulfide, 30 g. carbon tetrachloride, 47 g. acetylacetone, 56 g. ethylene dibromide, 44 g. benzene, approximately 200 g. Both the hydrate and the anhydrous compound give a red color with carbon disulfide on standing. This is also true of hafnium acetylacetonate but not of the thorium compound. 

What are our options for producing potable water from salt water Perhaps the most obvious design is an evaporator. The process separates vapor from liquid, which is easy and efficient. And because water boils at a temperature much lower than salt sublimes, the vapor phase will be essentially pure H2O. However, evaporation may require too much energy to be cost effective. Even if one makes liberal use of heat exchangers and condensers to reclaim the heat from the steam and the hot brine, the process still may be too expensive - although the energy costs will be reduced, the... 

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