Chlorine reaction with calcium

Bleaching powder. If, instead of cold sodium hydroxide, cold calcium hydroxide solution is used in reaction with chlorine, one obtains a solution containing calcium chloride and calcium hypochlorite ... 

Bleaching powder (chloride of lime) was first used industrially at the beginning of the nineteenth century and for over a century was the only transportable form of chlorine, since chlorine could be made available by acidification with hydrochloric acid. It contains ca. 36% of available chlorine. Since transportation of liquid chlorine became technically feasible at the beginning of the twentieth century, the manufacture of bleaching powder has steadily declined in importance. It is manufactured by reacting moist calcium hydroxide with chlorine, this reaction being fairly slow. 

Originally, the term oxidation referred only to reactions with oxygen. It now is used to describe any process in which the oxidation number of a species increases, even if oxygen is not involved in the reaction. When calcium combines with chlorine to form calcium chloride. 

Calcium thiosulfate is a clear crystalline substance, with a faintly sulfurous odor. It reacts with free as well as combined chlorine. Calcium thiosulfate undergoes the following reactions with chlorine (20) ... 

Calcium reacts with chlorine to form acom-pound called calcimn chloride, CaCl2, which is often used for deicing roads. In the reaction, each calcium atom loses two electrons while two chlorine atoms each gain one electron. Use the format shown in Table 4.2 to analyze this reaction. What role does the coefficient 2 play in the reaction ... 

LAPIS INFERNALIS (7761-88-8) A powerful oxidizer. Forms friction- and shock-sensitive compounds with many materials, including acetylene, anhydrous ammonia (produces compounds that are explosive when dry), 1,3-butadiyne, buten-3-yne, calcium carbide, dicopper acetylide. Contact with hydrogen peroxide causes violent decomposition to oxygen gas. Violent reaction with chlorine trifluoride, metal powders, nitrous acid, phosphonium iodide, red or yellow phosphorus, sulfur. Incompatible with acetylides, acrylonitrile, alcohols, alkalis, ammonium hydroxide, arsenic, arsenites, bromides, carbonates, carbon materials, chlorides, chlorosulfonic acid, cocaine chloride, hypophosphites, iodides, iodoform, magnesium, methyl acetylene, phosphates, phosphine, salts of antimony or iron, sodium salicylate, tannic acid, tartrates, thiocyanates. Attacks chemically active metals and some plastics, rubber, and coatings. 

SILVER NITRATE or SILVER(I) NITRATE (7761-88-8) A powerful oxidizer. Forms friction- and shock-sensitive compounds with many materials, including acetylene, anhydrous ammonia (produces compounds that are explosive when dry), 1,3-butadiyne, buten-3-yne, calcium carbide, dicopper acetylide. Contact with hydrogen peroxide causes violent decomposition to oxygen gas. Violent reaction with chlorine trifluoride, metal powders, nitrous acid. 

Reaction with chlorine. Dry hydrated limes readily react with chlorine forming bleaching powder — see section 31.3. Milks of lime also react with chlorine to produce bleach (a solution of calcium hypochlorite — equation 19.3). 

Formerly, the term oxidation meant reaction with oxygen. The current definition greatly enlarges the meaning of this term. Consider the reaction of calcium metal with chlorine gas (Figure 4.13) the reaction looks similar to the burning of calcium in oxygen. The chemical equation is... 

Sodium hypochlorite and calcium hypochlorite are chlorine derivatives formed by the reaction of chlorine with hydroxides. The appHcation of hypochlorite to water systems produces the hypochlorite ion and hypochlorous acid, just as the appHcation of chlorine gas does. 

Reaction of HOCl, formed from calcium hypochlorite and CO2, with highly substituted alkenes in CH2CI2 is a convenient route to aHyUc chlorides (111). Ketones are chlorinated to a-chloroketones by reaction with HOCl Acetone initially gives CH2COCH2CI (112). Methyl ethyl ketone gives 78% CH3CHCICOCH3, 15% CH3CH2COCH2CI, and 7% dichlorides (113). 

When treated with aluminum bromide at 100°C, carbon tetrachloride is converted to carbon tetrabromide [558-13-4], reaction with calcium iodide, Cal2, at 75°C gives carbon tetraiodide [507-25-5]. With concentrated hydroiodic acid at 130°C, iodoform [75-47-8], CHI, is produced. Carbon tetrachloride is unaffected by gaseous fluorine at ordinary temperatures. Replacement of its chlorine by fluorine is brought about by reaction with hydrogen fluoride at a... 

The dissociation of hypochlorous acid depends on the pH. The unionized acid is present in greater quantities in acid solution, although in strongly acid solution the reaction with water is reversed and chlorine is Hberated. In alkaline solutions the hypochlorite ion OCL is increasingly Hberated as the pH is increased. The pH is important because unionized hypochlorous acid is largely responsible for the antimicrobial action of chlorine in water. Chlorine compounds are therefore more active in the acid or neutral range. The hypochlorites most commonly employed are sodium hypochlorite [7681-52-9] or calcium hypochlorite [7778-54-3]. 

Butyl h3q)Ochlorite has been prepared by treatment of an alkaline solution of /-butyl alcohol with chlorine, - and a recent warning cautions against allowing the temperature to rise above 20° during this reaction. /-Butyl hypochlorite has been prepared in solution by shaking a solution of the alcohol in carbon tetrachloride, fluorotrichloromethane (Freon 11), and other solvents with aqueous hypochlorous acid. It has also been prepared by the action of chlorine on an aqueous /-butyl alcohol suspension of calcium carbonate, and by the action of chlorine monoxide on a carbon tetrachloride solution of the alcohol. ... 

Calcium hypochlorite is an oxidizing agent. It undergoes vigorous to violent reactions with reducing agents and organics. In aqueous solution, it dissociates to calcium and hypochlorite ions. The hypochlorite ions form hypochlor-ous acid and molecular chlorine, which coexist in equilibrium. 

Similar proposals have been made to treat the enormous quantities of calcium chloride obtained as a by-product in many industries either to obtain chlorine (q.v.) or hydrogen chloride. J. T. Pelouze 14 showed that when calcium chloride is mixed with sand to prevent fusion, it is readily decomposed by steam at a red heat with the copious evolution of hydrogen chloride, and the reaction was the basis of the E. Solvay patents in which the calcium chloride was mixed with sand or clay. W. Bramley mixed the calcium chloride with iron ore before heating it in a stream of air for chlorine, or with-steam for hydrogen chloride. W. H. Seamon proposed to treat molten calcium chloride with acetylene to produce calcium carbide and hydrogen chloride. 

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