Nitrate de calcium

Courgnaud, R.-P. and Tremillon, B. (1965) Reactions en solution dans le nitrate de calcium tetrahydrate fondu. 1. Reactions acides-bases. Bull. Soc. Chim. Fr., 752-764. 

Procedure. Pipette 25 mL of the test solution (which may contain both calcium and lead at concentrations of up to 0.01 M) into a 250 mL conical flask and dilute to 100 mL with de-ionised water. Add about 50 mg of methylthymol blue/potassium nitrate mixture followed by dilute nitric acid until the solution is yellow, and then add powdered hexamine until the solution has an intense blue colour (pH ca 6). Titrate with standard (0.01 M) EDTA solution until the colour turns to yellow this gives the titration value for lead. 

Polarography has also been applied to the determination of potassium in seawater [535]. The sample (1 ml) is heated to 70 °C and treated with 0.1 M sodium tetraphenylborate (1 ml). The precipitated potassium tetraphenylborate is filtered off, washed with 1% acetic acid, and dissolved in 5 ml acetone. This solution is treated with 3 ml 0.1 M thallium nitrate and 1.25 ml 2M sodium hydroxide, and the precipitate of thallium tetraphenylborate is filtered off. The filtrate is made up to 25 ml, and after de-aeration with nitrogen, unconsumed thallium is determined polarographically. There is no interference from 60 mg sodium, 0.2 mg calcium or magnesium, 20 pg barium, or 2.5 pg strontium. Standard eviations at concentrations of 375, 750, and 1125 pg potassium per ml were 26.4, 26.9, and 30.5, respectively. Results agreed with those obtained by flame photometry. 

Ammonium perchlorate, NH4C104.—The perchlorate is formed by mixing solutions of barium perchlorate and ammonium sulphate, by the action of ammonium nitrate on sodium perchlorate,8 and by that of ammonium chloride on calcium or magnesium perchlorate.10 It forms rhombic,11 doubly refracting crystals,12 of density 1 88 at 25° C. Its solubility at 18° C. is 21 07 grams in 100 grams of water.18 It is de-... 

PrecipUaHon processes are only adapted to hard waters, and are de s ed to separate the excess of calcium salt, and at the same time a considerable quantity of organic matter, which is mechanically carried down with the preeijiitate. e method usually followed consists in the addition of lime (in the form of lime-water), in just Bofi cieut ontity to neutralize the excess of carbon dioxide present w the water, llie added lime, together with the calcium salt naturally present in the -water, is then precipitated, except that small portion of calcium carbonate which the water, freed from carbon dioxide, is capable of dissolving. To determine when sufficient lime-water has been added, take a sample from time to time during the addition, and test it with solution of silver nitrate until a brown precipitate is formed. At this point cease the addition of lime-water and mix the limed water with further portions of the haid water, until a sample, treated with silver-nitrate solution, gives a yellowish in place of a brown color. 

DICLORURO de ESTANO (Spanish) (7772-99-8) A strong reducing agent. Reacts violently with strong oxidizers, strong alkalis, bromine, bromine trifluoiide, calcium carbide, chlorine, chlorine monofluoride, copper nitrate, fluorine, hydrogen peroxide, nitrates, potassium, potassium dioxide, sodium, with risk of fire and explosions. Incompatible with calcium acetylide, hydrazine hydrate, metal nitrates. 

FLUORURE de BORE (French) (7637-07-2) Reacts with moist air, water, steam, producing hydrogen fluoride, boric acid, and fluoboric acid. Violent reaction with allyl chloride, alkyl nitrate, benzyl nitrate, calcium oxide, ethyl ether, iodine, magnesium tetrahy-droaluminate, active metals (except magnesium). Used as a polymerization catalyst contact with monomers may cause explosions. Corrodes most metals in the presence of moisture. 

The name muride was suggested to Balard by Anglada, who says the editors of the Annales de Chimie had persuaded Balard to adopt the name brome . Balard describes the properties of bromine fully and also the discovery of ethylene dibromide. He discovered hypochlorous acid (acide chloreux) and chlorine monoxide, obtaining hypochlorous acid by the action of precipitated mercuric oxide on chlorine water, and chlorine monoxide by dehydrating a solution of hypochlorous acid with calcium nitrate the usual preparation by passing chlorine over precipitated mercuric oxide was described by Pelouze. Balard discovered oxamic acid (see p. 339) and investigated amyl alcohol (see p. 430). 

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