Calcium sulfate strong

Calcium Sulfate. Strongly exothermic reaction that may lead to detonation calcium sulfate should not be used to dry diazomethane. Potassium hydroxide is a suitable drying agent.8... 

Excess calcium hydroxide is precipitated by usiag carbon dioxide and the calcium carbonate, calcium hydroxide, and calcium phosphite are removed by filtration. The filtered solution is treated with an equivalent amount of sodium sulfate or sodium carbonate to precipitate calcium sulfate or carbonate. Sodium hypophosphite monohydrate [10039-56-2] is recovered upon concentration of the solution. Phosphinic acid is produced from the sodium salt by ion exchange (qv). The acid is sold as a 50 wt %, 30—32 wt %, or 10 wt % solution. The 30—32 wt % solution is sold as USP grade (Table 12) (63). Phosphinic acid and its salts are strong reduciag agents, especially ia alkaline solution (65). 

Calcium sulfate exhibits high thermal stability. At elevated temperatures, it occurs in anhydrous form. The dihydrate loses its water molecules upon strong heating. When ignited with charcoal, it is reduced to calcium sulfide ... 

A variety of organic adhesives which are capable of forming strong bonds between a polymeric (acrylate) restoration and the hydrophilic tooth material have recently been developed. A number of these monomers, which possess a pendent ionizable group, are polymerized in the mouth to form an adhesive layer. Alginates, which are used as impression materials, are formed by the reaction of the sodium salt of anhydro-beta-d-mannuronic acid with calcium sulfate. Calcium ions crosslink the linear polymer to form a gel. This reaction is carried out inside the mouth, and the gel formed retains the shape of the oral cavity. 

Gypsum is a compound composed of calcium ions and sulfate ions. It is mixed with water to make plaster. Plaster is a mixture, not a solution. Gypsum is insoluble in water because the attractive forces among the ions in calcium sulfate are so strong that they cannot be overcome by the attractive forces exerted by the water molecules. Solvation does not occur. 

Metal sulfates can be cracked to sulfur dioxide. This is the basis of the Muller-Kuhne process, which is operated in several Eastern European countries, the Federal Republic of Germany, Austria and South Africa, but whose importance has strongly diminished of late. In this process calcium sulfate (naturally occurring gypsum or anhydrite or gypsum from the manufacture of phosphoric acid) is reacted with coal in the presence of clay and sand in a rotary tube furnace a temperatures between 700 and 1200°C. Initially calcium sulfide and carbon dioxide are formed, which further react forming calcium oxide and sulfur dioxide ... 

Derivation Strong heating of pulverized calcium sulfate and charcoal. 

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