Chlorinated lime

Bleach Liquor. Bleach Hquor or lime bleach Hquor is an aqueous solution of calcium hypochlorite and calcium chloride. It typically contains 30—35 g/L of available chlorine, though it may be as high as 85 g/L. It has been used in pulp bleaching, when it can be made more cheaply than sodium hypochlorite. It is prepared on site by chlorinating lime solutions. 

One such decontaminant is supertropical bleach (STB). STB is a mixture of chlorinated lime and calcium oxide containing about 30% available chlorine. It can be used either as a dry mix or as a slurry to decontaminate some equipment surfaces and terrain. The dry mix is prepared with two parts bleach to three parts earth by volume. A slurry typically consists of 40 parts STB to 60 parts by weight of water. This material is then sprayed or swabbed on the contaminated surface (see Bleaching agents). STB is an effective decontaminant for mustard, lewisite, and VX. It is less effective against nerve agents other than VX. 

Chlorination of lime slurried in strong NaOCl solution, followed by cooling to — 15°C, precipitates about 80% of the av CI2 as large hexagonal crystals of a triple salt Ca(OCl)2 NaOCl NaCl -12H20 [64147-46-2] (182). The recovered triple salt, free of much of the lime impurities, is treated with chlorinated lime slurry to produce neutral calcium hypochlorite dihydrate crystals [22464-76-2]. 

Chlorination of thick lime slurry at 40—45°C forms large crystals of hemibasic calcium hypochlorite. The fine crystals obtained under 30°C are difficult to filter and since they invariably contain occluded mother Hquor, they have frequently been incorrectly referred to as monobasic or two-thirds basic (187,188). The isolated hemibasic crystals are suspended in a thin chlorinated lime slurry and chlorinated, producing laminar crystals of Ca(OCl)2 2H20, which are filtered and dried. Mother Hquors are treated with a lime slurry to recover the dibasic crystals, which are then suspended in a Hquor of lower CaCl2 content and chlorinated to form the neutral salt (188—190). 

Other processes also use the dibasic salt as an intermediate. Dibasic calcium hypochlorite can be prepared from filtrates from chlorinated lime slurries in various ways. In one process, the filtrate is returned to the slurry being chlorinated to keep it thin. This is designed to improve crystal growth. The dibasic crystals, together with water, are added to the slurry during chlorination and some dibasic salt is prepared by chlorination in addition to the dibasic salt made from filtrates (188). In another process, dibasic crystals are separated, slurried in water, and chlorinated to obtain a slurry of neutral Ca(OCl)2 2H20 in a mother Hquor of reduced calcium chloride content which is then filtered and air dried (191,192). 

The presence of acetanilide in these residues may be confirmed by boilin the residue for two to three minutes with HCl, and when cool, adding a few drops of 0 5 per cent, of chlorinated lime solution, in such a manner that the liquids do not mix. A fine blue colour results if acetanilide be present. 

Chlorinated lime or bleaching powder, CaOCl2, contains about 30% w/w of available chlorine. 

Theory Chlorinated lime reacts with acetic acid to produce a mole each of calcium acetate, hydrochloric acid and hydrochlorous acid. The two acids interact to give water and chlorine, and the latter reacts with HI to liberate iodine that can be estimated by titrating with 0.1 N sodium thiosulphate solution. The various reactions involved may be expressed as given below ... 

Materials Required Chlorinated lime 4 g dilute acetic acid 5 ml potassium iodide 3 g acetic acid 5 ml 0.1 N sodium thiosulphate solution. 

From this value the percentage of chlorine present in the given sample of chlorinated lime can be calculated. 

Other agents are also available, which are used to remove pigmentation of teeth e.g. weak ammonia solution is used to remove iodine stains, hypochlorite or iodine solution are used to remove silver stains, hypochlorites are used to remove iron stains of teeth and for dye stains, chlorinated lime and acetic acid are used. 

Put some chlorinated lime into a test tube and pour a 20% hydrochloric acid solution over it. Write the equation of the reaction. 

Add a solution of 1 iV sulphuric acid to a part of the prepared chlorinated lime solution until the reaction is acid and carefully smell the product. Write the equation of the reaction. What happens to chlorinated lime when its concentrated solution is heated ... 

Put a little chlorinated lime into test tube 7, and pour a concentrated ammonia solution into dropping funnel 2. Add the ammonia solution dropwise to the chlorinated lime and collect the evolved nitrogen in test tube 3 by putting it over the end of the gas-discharge tube. Write the equation of the reaction. See whether... 

Preparation of Chloroform. First prepare chlorinated lime. To do this, add 60-80 ml of water to 60 g of pure slaked lime placed in a beaker. Thoroughly stir the mixture. Put the beaker into a bath with ice and pass chlorine purified from hydrogen chloride into the mixture during two hours. 

Transfer the obtained chlorinated lime into the reaction flask of an apparatus for preparing chloroform (Fig. 106) and pour in 150 ml of water. Put a mixture of 20 ml of acetone and 20 ml of water into... 

Transfer the dry chloroform into the flask of an apparatus for distillation under atmospheric pressure (see Fig. 20). Collect the fraction boiling at 62 °C. Weigh the substance and calculate its yield in per cent. Write the equation of the reaction of chlorinated lime with acetone. 

Preparation of Nickel(III) Oxide. Pour a little of a sodium hydroxide solution into a small amount of a nickel sulphate one while stirring, and then add a chlorinated lime (calcium hypochlorite) solution (which must be absolutely transparent). Let the mixture stand for several hours until the evolution of oxygen bubbles stops. Next heat it up to boiling. Let the mixture settle and wash the precipitate by decantation. Write the equation of the reaction. 

Preparation and Properties of Lead(IV) Oxide, a. Prepare a saturated transparent solution of chlorinated lime and a solution of 3 g of lead acetate in 5 ml of water. Add an equal volume of a lead acetate solution heated to 50 °C to the first solution while stirring it. Heat the reaction mixture to 100-110 °C. Wash the precipitate first with water by decantation, and next with a dilute nitric acid solution (what ions are washed off here ). Filter off the product, again wash it two or three times on the funnel with water and dry it at 100 °C. Keep the preparation. Write the equation of the reaction. 

Aniline. — On pouring 1 gm. of powdered diphenylamine into 20 cc. of a chlorinated lime solution, the liquid should not acquire a violet color. 

Benzoquinone-l,4 di(chloro-iniine) [called Benzo-chinon-(1.4)-bis-chlorimid or p-Chinon-bis-chlor-imid in Ger], C1N CBH4 NC1 mw 175.02, N 16.01% ndls(from w) having a si aromatic odor, mp 124 -6°(dec) expl when heated rapidly above the mp readily sol in hot ale, hot AcOH, eth or benz si sol in hot w almost insol in cold w was first prepd by Krause(Ref 2) by treating an ice-cold soln of p-phenylenediamine in dil HC1 with, an excess of chlorinated lime(bleaching powder). 

Decontominoting Agent STB (also referred to as Bleach, Supertropical Bleach, Bleaching Powder, Bleaching Material, and Chlorinated Lime). STB is a wh powder contg 30% of available chlorine. 

Calcium hypochlorite is also manufactured by the formation under refrigeration of the complex salt Ca(OCl)2 Na0ClNaC112H20, which is prepared by the chlorination of a mixture of sodium hydroxide and calcium hydroxide. The salt is reacted with a chlorinated lime slurry, filtered to remove salt, and dried, resulting finally in a stable product containing 65 to 70% calcium hypochlorite. 

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