Chloride extraction

Figures 5 and 6 show how the water extractable chloride and bromide change with storage at 175 C and 200 C for a 1983 and a 1985 vintage flame retarded novolac epoxy. In both of these figures, the chloride, most of which comes from the ECN, changes from an initial concentration of <10 ppm to a maximum concentration of 17 ppm after 1000 hours at 175 C and 23 ppm after 1000 hours at 200 C. The amount of chloride extracted from both epoxies is similar. The water extractable bromide, however, increases for the 1983 epoxy after an induction period of about 168 hours. The bromide from the 1985 epoxy also increases, but at a much slower rate. These results show that the thermal stability problems of the brominated organic can be minimized, provided the flame retardant system is carefully selected.

Chloride. Aqueous chloride ion extraction data over the temperature range of 120°C to 250°C are presented in Figure 2. The amount of extracted chloride was less than 15 PPM at temperatures below 150°C. It increased to about 600- to 700 PPM around 200°C and leveled off. Unlike the data for bromide, Arrhenius plots of chloride concentration data were linear at all temperatures below 175°C for all of the resins. Besides, there was no... 

Fig. 27. Anionic analysis of 2.6 /tl of a silage extract. Chloride and bicarbonate served as leading (L) and terminating (T) anions, resp. The extract contained formate (For), lactate (Lac), acetate (Ac) and butyrate (But)...

Chloride 10 -1 -57, CN , 1, Br, S2( , SCN- Water analysis, soil extracts Chloride in sweat (cystic fibrosis) Food Analysis... 

Initial qualitative evidence that copolymer 54, which contains both calix[4]pyrrole and crown ether subunits, could extract chloride salts into organic media came from a visual test involving a water-soluble dye, 57, that contains a chloride counteranion. Treatment of an aqueous solution of the dye (25.5 mM) with a CH2CI2 solution of copolymer 54 (effective concentration of the calix[4]pyrrole and crown ether repeat units was 1.56 and 1.22 mm, respectively) resulted in a colored organic phase. 

Aluminium(ni) chloride extracts chloride ion from the phosphonium ylide, [ Bu2PCl(CPh2)], to give the salt, [ BU2P = CPh2][AlCl4], which melts at 108-109°C [522]. 

The goals of the electrochemical repair methods is to check ongoing corrosion of the rebars by increasing the alkalinity of the pore solution and to extract chlorides from the concrete cover. No official standard for the acceptance of the treatments exists, but at the end of the treatment the effectiveness should be checked. This can be done by direct measurements (half cell potential mapping) or by indirect means (chloride content, sodium profiles, total charge flow, etc.). 

Ionic impurities such as Cl, Na", and can cause corrosion of A1 bond pads and other metallization, loss in oxide dielectric strength in FET circuits, and other problems in high reliability (high rel) ICs. Until recently, most conductive epoxy adhesives contained very high levels of extractable chloride ions and other ionic impurities. The adhesives of Table 3, for example, would typically yeild over 600 ppm Cl and over 200 ppm Na, after a 24 hour extraction in neutral water at 100 C. 

The general characteristics of all these elements generally preclude their extraction by any method involving aqueous solution. For the lighter, less volatile metals (Li, Na, Be, Mg, Ca) electrolysis of a fused salt (usually the chloride), or of a mixture of salts, is used. The heavier, more volatile metals in each group can all be similarly obtained by electrolysis, but it is usually more convenient to take advantage of their volatility and obtain them from their oxides or chlorides by displacement, i.e. by general reactions such as... 

This reaction is also used on a large scale, to obtain iodine from seaweed. The ash from burnt seaweed ( kelp ) is extracted with water, concentrated, and the salts other than iodides (sulphates and chlorides) crystallise out. The more soluble iodides remain and the liquor is mixed with sulphuric acid and manganese dioxide added the evolved iodine distils off and is condensed. 

Scandium is not an uncommon element, but is difficult to extract. The only oxidation state in its compounds is -I- 3, where it has formally lost the 3d 4s electrons, and it shows virtually no transition characteristics. In fact, its chemistry is very similar to that of aluminium (for example hydrous oxide SC2O3, amphoteric forms a complex [ScFg] chloride SCCI3 hydrolysed by water). 

Iron(III) chloride forms numerous addition compounds, especially with organic molecules which contain donor atoms, for example ethers, alcohols, aldehydes, ketones and amines. Anhydrous iron(III) chloride is soluble in, for example, ether, and can be extracted into this solvent from water the extraction is more effective in presence of chloride ion. Of other iron(III) halides, iron(III) bromide and iron(III) iodide decompose rather readily into the +2 halide and halogen. 

Give the name and formula of one ore of mercury. How is the metal (a) extracted from this ore, (b) purified Starting from the metal, how would you prepare specimens of (c) mercury(I) chloride,... 

A certain amount of hydrolysis of the original acetamide to acid and ammonia always occurs, and the final amine always contains traces of ammonia. This is separated by extracting the mixed anhydrous hydrochlorides with absolute ethanol, which dissolves the amine hydrochloride but not the ammonium chloride filtration of the hot ethanolic extract removes the ammonium chloride, whilst the amine hydrochloride crystallises readily from the filtrate on cooling. 

Caution.—If the ethanol used to extract the methylamine hydrochloride is not absolute, i.e., if it contains traces of water, considerably less than the above suggested quantity will be required for the extraction, because the solubility of the hydrochloride will be markedly increased by the water present. The recrystallised material will now, however, contain traces of ammonium chloride. 

Place the distillate in a separating-funnel and extract the benzonitrile twice, using about 30 ml. of ether for each extraction. Return the united ethereal extracts to the funnel and shake with 10% sodium hydroxide solution to eliminate traces of phenol formed by decomposition of the benzenediazonium chloride. Then run off the lower aqueous layer, and shake the ethereal solution with about an equal volume of dilute sulphuric acid to remove traces of foul-smelling phenyl isocyanide (CaHjNC) which are always present. Finally separate the sulphuric acid as completely as possible, and shake the ether with water to ensure absence of acid. Run off the water and dry the benzonitrile solution over granular calcium chloride for about 20 minutes. 

During this period hydrogen chloride continues to be liberally evolved, and the product darkens considerably in colour. Now pour the product cautiously into 500 ml. of dilute hydrochloric acid and 100 g. of chipped ice in a separating-funnel, and shake the mixture thoroughly this operation removes the dark colour, and the toluene solution becomes yellow. Run off the lower acid layer, and extract the toluene three times with water. Finally dry the toluene solution over calcium chloride. 

The mixed amines are dissolved in hydrochloric acid and zinc chloride solution added. The quinoline chlorozincate, (C H7N)2,HtZnCl, crystallises out, being almost insoluble in water, while the aniline chlorozincate remains in solution. The quinoline chlorozincate is then filtered off and decomposed by alkalis, and the liberated quinoline extracted with ether or steam-distilled. 

Cool the remainder of the filtrate and extract three times with ether, using 20 - 30 ml. for each extraction. Dry the combined ethereal extracts over powdered anhydrous sodium sulphate. Filter into a small flask and distil off the ether on a water-bath. Pour the residual oil into a small dish or beaker crystallisation takes place almost immediately. The salicyl alcohol so obtained is almost pure, but it may, if so desired, be recrystallised from a small quantity of benzene. It is a colourless crystalline solid, m.p. 86 , readily soluble in water it gives a violet coloration with ferric chloride. 

The constant K is termed the distribution or partition coefficient. As a very rough approximation the distribution coefficient may be assumed equal to the ratio of the solubilities in the two solvents. Organic compounds are usually relatively more soluble in organic solvents than in water, hence they may be extracted from aqueous solutions. If electrolytes, e.g., sodium chloride, are added to the aqueous solution, the solubility of the organic substance is lowered, i.e., it will be salted out this will assist the extraction of the organic compound. 

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