Sodium carbonate, hydrated

Sodium carbonate hydrate contains water of crystallisation. When it is heated strongly it gives off the water of crystallisation, which can be collected. 

The basic aggression can be, in principle, due to the action of sodium and potassium carbonates, particularly to the sodium compounds [67], This can be considered as promoted by sodium lye together with carbonation of concrete. In this condition the sodium carbonate hydrates are formed and concrete is damaged by their crystallization. 

On standing, gelatinous aluminium hydroxide, which may initially have even more water occluded than indicated above, is converted into a form insoluble in both acids and alkalis, which is probably a hydrated form of the oxide AI2O3. Both forms, however, have strong adsorptive power and will adsorb dyes, a property long used by the textile trade to dye rayon. The cloth is first impregnated with an aluminium salt (for example sulphate or acetate) when addition of a little alkali, such as sodium carbonate, causes aluminium hydroxide to deposit in the pores of the material. The presence of this aluminium hydroxide in the cloth helps the dye to bite by ad sorbing it—hence the name mordant (Latin mordere = to bite) dye process. 

Add in turn 55 g. of anhydrous sodium carbonate, 27 g. of powdered arsenious oxide and i g. of hydrated copper sulphate to 175 ml. of water in a 2 litre beaker, and heat the stirred mixture until an almost clear solution is obtained then immerse the stirred solution in ice-water, and cool it to 5°. 

Valentinite, see Antimony(III) oxide Verdigris, see Copper acetate hydrate Vermillion, see Mercury(II) sulflde Villiaumite, see Sodium fluoride Vitamin B3, see Calcium (+)pantothenate Washing soda, see Sodium carbonate 10-water Whitlockite, see Calcium phosphate Willemite, see Zinc silicate(4—)... 

There are several processes available for the manufacture of cryoHte. The choice is mainly dictated by the cost and quaUty of the available sources of soda, alumina, and fluoriae. Starting materials iaclude sodium aluminate from Bayer s alumina process hydrogen fluoride from kiln gases or aqueous hydrofluoric acid sodium fluoride ammonium bifluoride, fluorosiUcic acid, fluoroboric acid, sodium fluosiUcate, and aluminum fluorosiUcate aluminum oxide, aluminum sulfate, aluminum chloride, alumina hydrate and sodium hydroxide, sodium carbonate, sodium chloride, and sodium aluminate. 

Both mono- and disodium phosphates are prepared commercially by neutralization of phosphoric acid using sodium carbonate or hydroxide. Crystals of a specific hydrate can then be obtained by evaporation of the resultant solution within the temperature range over which the hydrate is stable. For the preparation of trisodium phosphate, sodium hydroxide must be used to reach the high end pH because CO2 cannot be stripped readily from the solution above a pH of near 8. 

Causticization, the reaction of hydrated lime [1305-62-0], Ca(OH)2, with sodium carbonate to regenerate sodium hydroxide and precipitate calcium carbonate, is an important part of the Bayer process chemistry. 

Small amounts of sodium aluminate are prepared in the lab by fusion of equimolar quantities of sodium carbonate [497-19-8] and aluminum acetate [139-12-8], A1(C2H202)3, at 800°C (4). Other methods involve reaction of sodium hycboxide with amorphous alumina or aluminum [7429-90-5] metal. Commercial quantities of sodium aluminate are made from hydrated alumina, in the form of aluminum hydroxy oxide [24623-77-6], AIO(OH), or aluminum hycboxide [21645-51 -2], Al(OH)3, a product of the Bayer process (5,6) which is used to refine bauxite [1318-16-7], the principal aluminum ore. 

The hydrated alumina minerals usually occur in ooUtic stmctures (small spherical to eUipsoidal bodies the size of BB shot, about 2 mm in diameter) and also in larger and smaller stmctures. They impart harshness and resist fusion or fuse with difficulty in sodium carbonate, and may be suspected if the raw clay analyzes at more than 40% AI2O2. Optical properties are radically different from those of common clay minerals, and x-ray diffraction patterns and differential thermal analysis curves are distinctive. 

Tribasic coppersulfate is usually prepared by reaction of sodium carbonate and copper sulfate. As the temperature of the reaction contents increases so does the size of the resulting particle. For use as a crop fungicide, intermediate (40—60°C) temperatures are used to obtain a fine particle. When lower temperatures are used to precipitate basic copper(II) sulfate, products high in sulfate and water of hydration are obtained. 

Neutralization. The choice of a reagent for pH adjustment depends on cost ease and safety of storage and handling effectiveness, eg, for removing heavy metals, buffet characteristics of the pH titration curve as they affect pH control and avadabihty. The three principal reagents for neutralization of acid wastes are sodium hydroxide, sodium carbonate, and hydrated calcium hydroxide. 

This compound is readily soluble in water without regeneration of the citral from the solution either by sodium carbonate or hydrate. 

A mixture of 3.4 parts of 7-chloro-4-fluorobutyrophenone, 4 parts of 1-(4-piperidyl)-2-benzimidazolinone hydrochloride, 6 parts of sodium carbonate and 0.1 part of potassium iodide in 176 parts of 4-methyl-2-pentanone is stirred and refluxed for 48 hours. The reaction mixture is cooled and 120 parts of water is added. The separated organic layer is dried over magnesium sulfate and the solvent is evaporated to leave an oily residue which is dissolved in dilute hydrochloric acid and boiled. The acidic solution is filtered and cooled at room temperature whereupon there crystallizes from solution l-<1-[ y-(4-fluorobenzoyl)-propyl]-4-piperidvl>-2-benzimidazolinone hydrochloride hydrate melting at about 134°-142°C. 

The relation between moisture content and vapor pressure (or relative humidity) at constant temperature is expressed by an isotherm. Figures 1 and 2 show typical isotherms for a crystalline hydrate sodium carbonate and a food material (potato). 

Di- -tolylmercury (Coll. Vol. 1, 226) In 93.5 per cent yields by refluxing an alcoholic suspension of -tolylmejcurie chloride with sodium carbonate and hydrazine hydrate. Gilman and Barnett, Rec. tiav. chim. 55. 563 (1936). 

A student measures 10.0 g of hydrated sodium carbonate (Na2C03 xH20) and places it m a crucible. After heating, 3.7 g of anhydrous sodium carbonate (Na2C03) remains. What is the formula for the hydrate ... 

Formerly derived from the natural mineral lapis lazuli, ultramarine blue pigments have, for more than a century, been manufactured synthetically. The materials used in the manufacture of ultramarines are china clay (a hydrated aluminosilicate), sodium carbonate, silica, sulfur and a carbonaceous reducing material such as coal tar pitch. For the manufacture of the blue pigments, the blend of ingredients is heated to a temperature of 750 800 °C over a period of 50-100 h, and the reaction... 

Alum Borax Natron Iron vitriol Mineral Mineral Mineral Mineral or synthetic Sulfate of aluminum and other metals (e.g., potassium alum) Hydrated sodium borate Natural mixture sodium carbonate and sodium bicarbonate Hydrated iron sulfate... 

Besides the amorphous alumina films formed in the majority of acidic electrolytes (except those formed in chromic acid and exhibiting traces of y-Al203194), there are possibilities of forming oxides with a more or less pronounced crystallinity. These oxides are formed in alkaline solutions195 and especially in sodium carbonate baths.196 According to the data provided by Hiroshi and Yoshimura,197 these oxides contain a y- A1203 phase easily hydrated and converted into a bayerite-like substance. 

For most uses, the Na2C03 must be purified. This is done by dissolving it in water and separating insoluble rocky material by filtration. Organic impurities are removed by adsorption using activated charcoal. The hydrated crystals of Na2C03-H20 are obtained by boiling off the excess water to concentrate the solution. The hydrated crystals are heated in a rotary kiln to obtain anhydrous sodium carbonate ... 

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