Calcium chloride solutions

It should be emphasised that the calcium chloride solution used in testing for acids is of Reagent concentration (p. 524) throughout. 

Commercial diethyl carbonate may be purified by the following process. Wash 100 ml. of diethyl carbonate successively with 20 ml. of 10 per cent, sodium carbonate solution, 20 ml. of saturated calcium chloride solution, and 25 ml. of water. Allow to stand for one hour over anhydrous calcium chloride with occasional shaking, filter into a dry fiask containing 5 g. of the same desiccant, and allow to stand for a further hour. Distil and collect the fraction boiling at 125-126°. Diethyl carbonate combines with anhydrous calcium chloride slowly and prolonged contact should therefore be avoided. Anhydrous calcium sulphate may also be used. 

An alternative method for isolating the n-butyl ether utilises the fact that n-butyl alcohol is soluble in saturated calcium chloride solution whilst n-butyl ether is slightly soluble. Cool the reaction mixture in ice and transfer to a separatory fimnel. Wash cautiously with 100 ml. of 2-5-3N sodium hydroxide solution the washings should be alkaline to litmus. Then wash with 30 ml. of water, followed by 30 ml. of saturated calcium chloride solution. Dry with 2-3 g. of anhydrous calcium chloride, filter and distil. Collect the di-n-butyl ether at 139-142°. The yield is 20 g. 

Separate the ketone layer from the water, and redistil the lattCT rmtil about one third of the material has passed over. Remove the ketone after salting out any dissolved ketone with potassium carbonate (5). Wash the combined ketone fractions four times with one third the volume of 35-40 per cent, calcium chloride solution in order to remove the alcohol. Dry over 15 g. of anhydrous calcium chloride it is best to shake in a separatory funnel with 1-2 g. of the anhydrous calcium chloride, remove the saturated solution of calcium chloride as formed, and then allow to stand over 10 g. of calcium chloride in a dry flask. Filter and distil. Collect the methyl n-butyl ketone at 126-128°. The yield is 71 g. 

Add a few drops of saturated calcium chloride solution, and allow to stand for several hours. If fluorine is present, a gelatinous precipitate of calcium fluoride will form. 

The synthetic and plasmid DNAs are mixed and join their sticky ends spontaneously. They are covalently bound together by DNA ligases, when the resulting hybrid plasmid is inserted into bacterial cells. Dilute calcium chloride solutions render the bacterial membranes permeable and allow the passage of ONA into the cells. 

This carbon dioxide-free solution is usually treated in an external, weU-agitated liming tank called a "prelimer." Then the ammonium chloride reacts with milk of lime and the resultant ammonia gas is vented back to the distiller. Hot calcium chloride solution, containing residual ammonia in the form of ammonium hydroxide, flows back to a lower section of the distiller. Low pressure steam sweeps practically all of the ammonia out of the limed solution. The final solution, known as "distiller waste," contains calcium chloride, unreacted sodium chloride, and excess lime. It is diluted by the condensed steam and the water in which the lime was conveyed to the reaction. Distiller waste also contains inert soHds brought in with the lime. In some plants, calcium chloride [10045-52-4], CaCl, is recovered from part of this solution. Close control of the distillation process is requited in order to thoroughly strip carbon dioxide, avoid waste of lime, and achieve nearly complete ammonia recovery. The hot (56°C) mixture of wet ammonia and carbon dioxide leaving the top of the distiller is cooled to remove water vapor before being sent back to the ammonia absorber. 

Viscosity is an important property of calcium chloride solutions in terms of engineering design and in appHcation of such solutions to flow through porous media. Data and equations for estimating viscosities of calcium chloride solutions over the temperature range of 20—50°C are available (4). For example, at 25°C and in the concentration range from 0.27 to 5.1 molal (2.87—36.1 wt %) CaCl2, the viscosity increases from 0.96 to 5.10 mPa-s (=cP). 

There are 10 producers of calcium chloride solutions in the United States, three of these also make a dry product. Solution production is centered around Michigan (brines), California and Utah (brines), and Louisiana (by-product acid). The majority of dry calcium chloride is made in Michigan, lesser quantities in Louisiana, and minor quantities in California. Production involves removal of other chlorides (primarily magnesium) by precipitation and filtration followed by concentration of the calcium chloride solution, either for ultimate sale, or for feed for dry product. Commercial dry products vary by the amount of water removed and by the nature of the drying equipment used. Production and capacity figures for the United States are indicated in Table 2. 

Roadbed Stabilization/Dust Control. One of the earliest uses of calcium chloride was for dust control and roadbed stabilization of unpaved gravel roads. Calcium chloride ia both dry and solution forms are used both topically and mixed with the aggregate. When a calcium chloride solution is sprayed on a dusty road surface, it absorbs moisture from the atmosphere binding the dust particles and keeping the surface damp. Calcium chloride does not evaporate, thus this dust-free condition is retained over along period of time. 

If aggregate is mixed with dry calcium chloride or a calcium chloride solution and then compacted, the presence of the calcium chloride draws ia moisture to biad the fine particles ia the aggregate matrix. This process leads to a well compacted, maximum deasity gravel road. This appHcatioa for calcium chloride was reviewed ia 1958 (27). More receat pubHcatioas are also available (28—30). 

Calcium chloride solutions, typically employed at 2—5% concentration, are used as antispasmodics, diuretics (qv), and in the treatment of tetany. Concentrated solutions of calcium chloride cause erythema, exfoUation, ulceration, and scarring of the skin (39). Injections into the tissue may cause necrosis. If given orally calcium chloride can cause irrita tion to the gastrointestinal tract unless accompanied by a demulcent. There is no pubHshed information on mutagenicity or carcinogenicity caused by calcium ions or calcium chloride. Calcium chloride has been given a toxicity or hazard level 3 (40). Materials in this classification typically have LD q below 400 mg/kg or an LC q below 100 ppm. 

Reactions.— r. Make a strong neutral solution, add calcium chloride solution and boil. The calcium salt is precipitated. 

Boil the tartaric acid and caustic soda solution for three hours in a round flask (I litre), or preferably in a tin bottle furnished with reflu. condenser. The use of a tin vessel obviates certain clitli-cultiesof filtration which the solution of the silica by the action of the alkali on the glass entails. The liquid, after boilinjg, is carefully neutralised with cone, hydrochloric acid (it is acl is-able to remove a little of the solution beforehand in case overshooting the mark) and an excess of calcium chloride solution is added to the hot liquid. The mixture is left overni hl. and the calcium salts filtered off at the pump, washed with water, and well pressed. 

When the temperature of the plasma reaches about 5° to 8°C, the calculated quantity of calcium chloride solution is added in amount which is from 0.2 to 0.3% in excess of that needed to react with and precipitate the anticoagulant. The temperature of the plasma is allowed to rise to about 24°C. At 18° to 24°C strands of fibrin begin to appear and the... 

Calcium chloride solutions Sodium chloride solutions COj liquid Chlorine liquid Methanol solutions Ethanol solutions Ethylene glycol solutions... 

Prepared saltwater completion fluids are made of fresh surface water, with sufficient salts added to produce the proper salt concentration. Usually, the addition of 5 to 10% NaCl, 2% CaClj, or 2% KCl is considered satisfactory for clay inhibition in most formations. Sodium chloride solutions have been extensively used for many years as completion fluids these brines have densities up to 10 Ib/gal. Calcium chloride solutions may have densities up to 11.7 lb/ gal. The limitations of CaClj solutions are (1) flocculation of certain clays, causing permeability reduction, and (2) high pH (10 to 10.5) that may accelerate formation clays dispersion. In such cases, CaC12-based completion fluids should be replaced with potassium chloride solutions. Other clear brines can be formulated using various salts over wide range of densities, as shown in Figure 4-123 [28]. 

Table 3.39 Bimetallic corrosion between nickel and nickel-iron alloys in l6<7o calcium chloride solution ...

Fig. 8.33 Effect of cold work (%) on the susceptibility to cracking of type 321 stainless steel in boiling magnesium chloride and calcium chloride solutions (after Sedriks )...

English physicist and electrochemist Michael Faraday in 1823. You can make it by bubbling chlorine gas through calcium chloride solution at 0°C the hydrate comes down as feathery white crystals. In the winter of 1914, the Geiman army used chlorine in chemical warfare on the Russian front against the soldiers of the Tsar. They were puzzled by its ineffectiveness not until spring was deadly chlorine gas liberated from the hydrate, which is stable at cold temperatures. 

The solution is cooled and then diluted with 450 cc. of water. The oily layer of chloronitrile is collected in about 80 cc. of chloroform and Separated from the water solution. The chloroform solution is washed with about 125-150CC. of calcium chloride solution (prepared by adding one volume of water to an equal volume of a saturated solution of crystallized calcium chloride) and once with 125-150 cc. of water, and then dried over fused calcium chloride. 

Nickel may be determined in the presence of a large excess of iron(III) in weakly acidic solution by adding EDTA and triethanolamine the intense brown precipitate dissolves upon the addition of aqueous sodium hydroxide to yield a colourless solution. The iron(III) is present as the triethanolamine complex and only the nickel is complexed by the EDTA. The excess of EDTA is back-titrated with standard calcium chloride solution in the presence of thymolphthalexone indicator. The colour change is from colourless or very pale blue to an intense blue. The nickel-EDTA complex has a faint blue colour the solution should contain less than 35 mg of nickel per 100 mL. 

Procedure. Prepare a standard calcium chloride solution (0.01 M) by dissolving 1.000 g of calcium carbonate in the minimum volume of dilute hydrochloric acid and diluting to 1 L with de-ionised water in a graduated flask. Also prepare a 20 per cent aqueous solution of triethanolamine. 

Determination of oxalate as calcium oxalate and as calcium carbonate or calcium oxide Discussion. The neutral solution of alkali oxalate is acidified with acetic (ethanoic) acid, heated to boiling, and precipitated with boiling calcium chloride solution. After standing for 12 hours, the precipitate is filtered off, washed with hot water, and weighed either as calcium oxalate, or after heating, as calcium carbonate, CaC03, or as calcium oxide, CaO. Further details are given in Section 11.22. 

Sodium alginate (Fisher Scientific, Manchester, UK) was prepared by dissolving 10 g of powder form in 500 ml of distilled water. A separate solution of 120 g of calcium chloride was dissolved in 21 of distilled water. Sodium alginate and calcium chloride solution were... 

Glaser and Lichtenstein (G3) measured the liquid residence-time distribution for cocurrent downward flow of gas and liquid in columns of -in., 2-in., and 1-ft diameter packed with porous or nonporous -pg-in. or -in. cylindrical packings. The fluid media were an aqueous calcium chloride solution and air in one series of experiments and kerosene and hydrogen in another. Pulses of radioactive tracer (carbon-12, phosphorous-32, or rubi-dium-86) were injected outside the column, and the effluent concentration measured by Geiger counter. Axial dispersion was characterized by variability (defined as the standard deviation of residence time divided by the average residence time), and corrections for end effects were included in the analysis. The experiments indicate no effect of bed diameter upon variability. For a packed bed of porous particles, variability was found to consist of three components (1) Variability due to bulk flow through the bed... 

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