Sodium sulfate.decahydrate

In the days of alchemy and the phlogiston theory, no system of nomenclature that would be considered logical ia the 1990s was possible. Names were not based on composition, but on historical association, eg, Glauber s salt for sodium sulfate decahydrate and Epsom salt for magnesium sulfate physical characteristics, eg, spirit of wiae for ethanol, oil of vitriol for sulfuric acid, butter of antimony for antimony trichloride, Hver of sulfur for potassium sulfide, and cream of tartar for potassium hydrogen tartrate or physiological behavior, eg, caustic soda for sodium hydroxide. Some of these common or trivial names persist, especially ia the nonchemical Hterature. Such names were a necessity at the time they were iatroduced because the concept of molecular stmcture had not been developed, and even elemental composition was incomplete or iadeterminate for many substances. 

Sodium sulfate decahydrate melts incongmently at 32.4°C to a sulfate Hquid phase and an anhydrous sulfate soHd phase. The presence of other salts, such as NaCl, can depress the melting poiat to 17.9°C. 

Glaubersalz, n. Glauber s salt (sodium sulfate decahydrate). 

K. S. Pitzer and L. V. Coulter. "The Heat Capacities. Entropies and Heats of Solution of Anhydrous Sodium Sulfate and of Sodium Sulfate Decahydrate. The Application of the Third Law of Thermodynamics to Hydrated Crystals". J. Am. Chem. Soc.. 60. 1310-1313 (1938). 

G. Brodale and W. F. Giauque, "The Heat of Hydration of Sodium Sulfate. Low Temperature Heat Capacity and Entropy of Sodium Sulfate Decahydrate", J. Am. Chem. Soc., 80, 2042-2044 (1958). 

The distinction can be important if you buy sodium sulfate decahydrate, Na2SO410H2O, instead of its anhydrous form, Na,S04, you are buying a lot of water ... 

Near room temperature most gases become less soluble in water as the temperature is raised. The lower solubility of gases in warm water is responsible for the tiny bubbles that appear when cool water from the faucet is left to stand in a warm room. The bubbles consist of air that dissolved when the water was cooler it comes out of solution as the temperature rises. In contrast, most ionic and molecular solids are more soluble in warm water than in cold (Fig. 8.22). We make use of this characteristic in the laboratory to dissolve a substance and to grow crystals by letting a saturated solution cool slowly. However, a few solids containing ions that are extensively hydrated in water, such as lithium carbonate, are less soluble at high temperatures than at low. A small number of compounds show a mixed behavior. For example, the solubility of sodium sulfate decahydrate increases up to 32°C but then decreases as the temperature is raised further. 

Describe the processes occurring with the sodium sulfate decahydrate. 

It appeared that the large, well-defined crystals of sodium sulfate decahydrate, Na2S04 ... 

B. (2S, 3R)-2,4-Dimethyl-1,3-pentanediol3. To a stirred solution of (+)-2 (2.75 g, 5 mmol, 96 4 isomeric purity) in tetrahydrofuran (THF) (50 mL) is added lithium aluminum hydride (0.19 g, 5 mmol) at 0°C. The reaction mixture is stirred at room temperature for 1 hr and quenched by the careful addition of sodium sulfate decahydrate (5 g). The mixture is stirred vigorously for 30 min and filtered. The filtrate is concentrated, dissolved in 75 mL of a 1 1 mixture of hexane and dichloromethane. This solution is dried over sodium sulfate, filtered and concentrated under reduced pressure. Trituration of the resulting oil with hexane (50 ml) results in the precipitation of auxiliary alcohol 4 (1.6-1.8 g) which is recovered by filtration (Note 11). The residue is separated by chromatography over silica gel (40 g) (Note 2) with hexane and ethyl acetate (3 1-1 1) to afford additional 4 (0.2-0.4 g. Note 12) and 3 (0.60 g, 92%) (Notes 13, 14). 

If seeding with sodium sulfate decahydrate is omitted, the unstable heptahydrate may crystallize. 

The object of the experiment described below is to set up a gas thermometer, calibrate it at the ice point (in lieu of the experimentally more difficult triple point), and use it to determine the temperatures of one or more other fixed points. These may include the steam point, the boiling point of liquid nitrogen, the sublimation temperature of solid carbon dioxide (Dry Ice), the transition temperature of sodium sulfate decahydrate to the monohydrate and saturated solution, etc. The experiment will be performed with an apparatus that... 

Two other methods exist for preparing hydrazodicarbonamide. In the first method urea and dimethylketazine are reacted in the presence of either ammonium sulfate or sodium sulfate decahydrate (1) as illustrated in Eq 2 ... 

For example, when sodium sulfate crystallizes from aqueous solution below 40°C the crystals that form are anhydrous Na2S04, while above 40°C each molecule of Na2S04 that crystallizes has 10 molecules of water associated with it. The hydrated salt, Na2SO4T0H2O(s), is called sodium sulfate decahydrate. The change from the anhydrous to the hydrated form of the solid at 40°C is responsible for the discontinuity in the plot of Figure 6.5-1. Another solute that forms hydrated salts is magnesium sulfate, which can exist in five different forms in different temperature ranges. (See Table 6.5-1.)... 

Na2H20O14S sodium sulfate decahydrate 7727-73-3 25.00 1.4600 1 3170 Ni2B nickel boride 12007-01-1 25.00 7.9000 1... 

Further evidence of specific chemical effects in the hot zone appears in the work of Aten, who investigated the distribution of oxidation states of formed by the n,p reaction in irradiated inorganic sulfur compounds (S). When he irradiated solid potassium sulfate or sodium sulfate decahydrate, only a few per cent of the recoils were in lower (nonphosphate) oxidation states. With sodium sulfite (hydrated) the percentage rose to about 50%, while for sodium sulfide 65% to 95% were in lower oxidation states. He found similar correlations when the P was produced by the Cl (n,a) process. Here, the irradiation of KCIO3 or KCIO4 produced 99% phosphate, while NaCl gave only 35%. 

If the temperature is allowed to fall below 15°, large amounts of sodium sulfate decahydrate crystallize with the product. If this happens it may be necessary to recrystallize the /er/.-butylurea several times. 

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