Magnesium sulfate-water system

Kargel JS, Head JW III, Hogenboom DL, Khurana KK, Marion GM (2001) The system sulfuric acid-magnesium sulfate-water Europa s ocean properties related to thermal state. Lunar and Planetary Science Conference XXXII, Houston TX. Abstract 2138... 

Fig. 3.—Phase Diagrams of Two Ternary Systems Amylose-Magnesium Sulfate-Water (Solid Curves) and Amylopectin-Magnesium Sulfate-Water (Dotted Curves).

Probably the most satisfactory method of calculating heat effects during a crystallization process is to use the enthalpy-concentration chart for the solution and the various solid phases which are present for the system. However, only a few such charts are available, including the following systems calcium chloride-water.,(HI), magnesium sulfate-water (P2), and ferrous sulfate-water (K2). When such a chart is available, the following procedure is used. The enthalpy if, of the entering solution at the initial temperature is read off the chart, where//, is kJ (btu) for the total feed. The enthalpy i/j of the final mixture of crystals and mother liquor at the final temperature is also read off the chart. If some evaporation occurs, the enthalpy Hy of the water vapor is obtained from the steam tables. Then the total heat absorbed q in kJ is... 

A wide variety of precipitates form in cooling water systems carbonates, silicates, sulfates, and phosphates are common. Below and slightly above 212°F (100°C), calcite, aragonite, gypsum, hydroxyapatite, magnesium phosphate, anhydrite, and serpentine are commonly encountered (see Table 4.1). 

The ice bath is removed after addition of the sodium cyanide, and the mixture is stirred for 4 hours. The organic layer is separated, and the aqueous layer is extracted with three 500-ml. portions of ether. The combined ethereal extracts and organic layer are washed with two 100-ml. portions of cold water and dried over anhydrous magnesium sulfate. The ethereal solution is filtered, and the ether is removed at atmospheric pressure. The residue is transferred to a vacuum distillation system and distilled under reduced pressure (Cauiionl See Note 2). The yield of dlmethylaminophenylacetonitrile boiling at 88-90°/l.9-2.1 tnm. is 842 844 g. (87-88%) (Notes 3 and 4). 

Potassium iodide, 20 634 Potassium ions, 20 597, 598, 641 in soap-water system, 22 727 Potassium isotopes, 20 598 Potassium magnesium sulfate, 20 626 Potassium manganate(V), 15 592 Potassium manganate(VI), 15 594-596 Potassium metal, 20 604 production of, 20 600 reducing power of, 20 599 Potassium muds, 9 4 Potassium niobate, 17 152-153 Potassium nitrate, 20 609, 634-636 solubility of, 20 636t uses of, 20 636... 

Amines such as diethylamine, morpholine, pyridine, and /V, /V, /V, /V -tetramethylethylene-diamine are used to solubilize the metal salt and increase the pH of the reaction system so as to lower the oxidation potential of the phenol reactant. The polymerization does not proceed if one uses an amine that forms an insoluble metal complex. Some copper-amine catalysts are inactivated by hydrolysis via the water formed as a by-product of polymerization. The presence of a desiccant such as anhydrous magnesium sulfate or 4-A molecular sieve in the reaction mixture prevents this inactivation. Polymerization is terminated by sweeping the reaction system with nitrogen and the catalyst is inactivated and removed by using an aqueous chelating agent. 

C. 1- Butyl-3-methylimidazolium hexafluorophosphate. A 1-L, one-necked, round-bottomed flask (Note 13) is charged with 65.6 g (0.37 mol, 1 equiv) of 1- butyl-3-methylimidazolium chloride, and 69.3 g (0.37 mol, 1 equiv) of potassium hexafluorophosphate (Note 19) in 70 ml of distilled water. The reaction mixture is stirred at room temperature for 2 hr affording a two-phase system. The organic phase is washed with 3 X 50 mL of water and dried under reduced pressure (0.1 mbar, 0.001 mm). Then 100 ml of dichloromethane and 35 g of anhydrous magnesium sulfate are added. After 1 hr, the suspension is filtered and the volatile material is removed under reduced pressure (0.1 bar, 0. 1 mm) at 30°C for 2 hr to afford 86.4 g (0.29 mol, 81%) of 1- butyl-3-methylimidazolium hexafluorophosphate as alight yellow viscous liquid, mp 10°C (Notes 20 and 21). 

In a well-ventilated hood, behind a safety shield, to a stirred solution-of 523.6 mg (4.00 mmoles) of IV-acetyl-O-t-butylhydroxylamine and 0.48 ml of dry pyridine in 6 ml of carbon tetrachloride, cooled to — 10°C, is added drop-wise a saturated solution of nitrosyl chloride in 12 ml of carbon tetrachloride. After addition of the nitrosating agent has been completed, the reaction mixture is stirred for an additional hour at -10°C. Then, while maintaining the system at 0°C, the reaction mixture is washed in turn with 25 ml portions of water, a 10 % aqueous solution of hydrochloric acid, a 10 % solution of sodium bicarbonate solution, and finally with water again. The organic layer is separated and dried over anhydrous magnesium sulfate. 

Figure 16.2. Some phase diagrams, (a) The water end of the system potassium chloride and water, (b) The water end of the system sodium chloride and water, (c) The water end of the system magnesium sulfate and water the heptahydrate goes to the mono at 150°C, and to anhydrous at 200°C. (d) /3-methylnaphthalene and /S-chloronaphthalene form solid solutions, (e) Mixtures of formamide and pyridine form a simple eutectic, (f) These mixtures form binary eutectics at the indicated temperatures and a ternary eutectic at mol fractions 0.392 dibenzyl, 0.338 diphenyl, and 0.27 naphthalene.

The general procedure for the electrochemical preparation of (10) is as follows. A solution of (9) (3 mmol) in wet acetonitrile (40 ml, 5 vol.% of H20) containing sodium perchlorate (0.25 m) was placed in an undivided electrolysis cell equipped with a platinum plate anode and a platinum plate cathode. The system was subjected to a constant current electrolysis (300 mA current density, 20mAcnr2) at ambient temperature. After 4 faradays per mole of (9) had been consumed, the electrolysed solution was poured into water (50 ml) and extracted with dichloromethane (3 X 30 ml). The organic layer was dried with magnesium sulfate and concentrated under reduced pressure. The residue was chromatographed on silica gel to afford (10) in an excellent yield. 

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