Magnesium hexahydrate

Figure 12. Comparison of potential energy curves for dehydration of magnesium hexahydrate and monohydrate using DFT and effective potentials developed in this work.

An example of p-nitrosophenolate anion is very spectacular indeed. In various salts this anion is differently hydrated and this is a cause of variation of the ring geometry and consequently of the energy content of the ring. Figure 6 shows the relevant data for p-nitrosophenolates of sodium (trihydrate) [29], magnesium (hexahydrate) [30], and lithium (dihydrate) [31]. 

Table 2. Physical Properties of Magnesium Bromide and Magnesium Bromide Hexahydrate ...

Uses and Economic Aspects. Magnesium bromide is used in medicine as a sedative in treatment of nervous disorders, in electrolyte paste for magnesium dry cells, and as a reagent in organic synthesis reactions. The price of magnesium bromide hexahydrate in January 1995 was 5.51/kg (33). 

Magnesium chloride also forms hydrates containing 8 and 12 molecules of water of hydration. The solubiUty for MgCl2 ia water is shown in Figure 2 (31) from which it can be seen that the hexahydrate is the only stable hydrate in the range of temperatures from 0 to 100°C. 

In preparation of MgCl2 from seawater, magnesium hydroxide, Mg(OH)2, is first precipitated from seawater by the addition of dolime or lime. This is then treated with hydrochloric acid to produce a neutralized magnesium chloride solution. The solution obtained is evaporated and converted into soHd magnesium chloride hexahydrate (60,61). 

Anhydrous magnesium nitrate [10377-60-3] Mg(N02)2, is very difficult to isolate. The commercial product is the deUquescent hexahydrate [13446-18-9] Mg(N02)2 6H20. As illustrated in the solubiUty curve in Figure 7, the hexahydrate is the stable soHd phase between —18 and 55—56°C. Properties are given in Table 17 (1 4). The unit ceU contains two formula units and the calculated density is 1.643 g/cm. ... 

An aqueous solution of mono ammonium phosphate [10361-65-6] reacts with MgO to form ammonium magnesium phosphate hexahydrate [15490-91-2], NH MgPO 6H20. Several other species of hydrated phosphates are created during this reaction which takes place quickly and produces compounds that have desirable properties as cementing agents. The hexahydrate is the most prevalent. Properties are given in Table 22. 

Three peroxyacids are produced commercially for the merchant market peroxyacetic acid as a 40 wt % solution in acetic acid, y -chloroperoxybenzoic acid, and magnesium monoperoxyphthalate hexahydrate. Other peroxyacids are produced for captive use, eg, peroxyformic acid generated in situ as an epoxidizing agent. 

Many other metal thiosulfates, eg, magnesium thiosulfate [10124-53-5] and its hexahydrate [13446-30-5] have been prepared on a laboratory scale, but with the exception of the calcium, barium [35112-53-9] and lead compounds, these are of Httle commercial or technical interest. Although thaHous [13453-46-8] silver, lead, and barium thiosulfates are only slightly soluble, other metal thiosulfates are usually soluble in water. The lead and silver salts are anhydrous the others usually form more than one hydrate. Aqueous solutions are stable at low temperatures and in the absence of air. The chemical properties are those of thiosulfates and the respective cation. 

Chemical Designations - Synonyms Anhydione Dehydrite Magnesium perchlorate, anhydrous Magnesium perchlorate, hexahydrate Chemical Formula Mg(C104)2. 

Dithioglycerol is prepared in the following manner 1,537 parts of sodium monosulfide nonahydrate and 411 parts of powdered sulfur are dissolved with stirring in 1,345 parts of water. Magnesium hydroxide is precipitated in the stirred sodium trisulfide solution by adding successively 97 parts of sodium hydroxide dissolved in 180 parts of water and then slowly 246 parts of magnesium chloride hexahydrate dissolved in 180 parts of water. The... 

A mixture of DMF and magnesium nitrate hexahydrate decomposed violently when it was heated above the salt s melting point. It was thought that in those conditions, nitric acid had formed and oxidised DMF. 

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