Complex salt solutions

The Pt complex salt was dissolved in water. And the R complex salt solution was mixed with a mixture of surfactant, water and ethanol. After that, Na2COs resorcinol and formaldehyde were added to the solution. The molar ratio of the solution is O.llM l.OS 3.0R 16F l.ONazCOs 75EtOH SOOOHzO. The mixture was stirred at 30 C for 12 h and then heated at 90°C in a closed vessel for 12 h. The obtained polymer was carbonized under N2 atmosphere at 800°C for 7 h with a heating rate of 1°C min And then the Pt was reduced in H2 atmosphere at 300°C for 3 h with a heating rate of 1°C min. We denote the products as Pt/C. 

The truly remarkable thing about the Pitzer equations (17.40) to (17.42) is that the above parameters derived from one- and two-salt systems can be used with extraordinary success to predict behavior in systems containing many more ionic components. Use of the Pitzer equations to predict activities in very complex salt solutions requires data for the single-salt parameters f MX I MX C mx for possible com-... 

Cementation and Prevention of it by Deposition from the Complex Salt Solutions... 

Popov KI, Krstajic NV, Popov SR (1983) Fundamental aspects of plating technology. II morphological aspects of metal electrodeposition from complex salt solutions. Surf Technol 20 203-208... 

This means that if the resistance of the electrolyte is lower, it is lower the difference between the current densities in the middle and at the tip of the electrode. The increase in also leads to a more uniform current distribution. This can happen in the presence of strongly adsorbed species or during deposition from some complex salt solution. It is also seen that current density distribution on a... 

Deposition from a Complex Salt Solution (Effect of Exchange Current Density)... 

Bromley felt that treating a multicomponent solution as a single complex salt solution would be the simplest approach towards calculating the activity coefficients of electrolytes in solution. The Fj terms would then be based on the ionic interactions of this "complex salt". Using the convention that odd number subscripts denote cations and even number subscripts indicate anions, he proposed for a cation ... 

The above mentioned Schiff base (I) forms with metal ions colored inner complex salts. Solutions of calcium, barium and strontium salts when... 

How ever, the Mn(II) ion forms a variety of complexes in solution, some of which may be more easily oxidised these complexes can be either tetrahedral, for example [MnClJ , or octahedral, for example [Mn(CN)f,] Addition of ammonia to an aqueous solution of a manganese(II) salt precipitates Mn(OH)2 reaction of ammonia with anhydrous manganese(II) salts can yield the ion [MnfNH y T... 

Esters react witli hydroxylamine to form an alcohol and a hydroxamic acid, RCONHOH. All hydroxamic acids, in acid solutions, react with ferric chloride to form coloured (usually violet) complex salts ... 

Breslow studied the dimerisation of cyclopentadiene and the reaction between substituted maleimides and 9-(hydroxymethyl)anthracene in alcohol-water mixtures. He successfully correlated the rate constant with the solubility of the starting materials for each Diels-Alder reaction. From these relations he estimated the change in solvent accessible surface between initial state and activated complex " . Again, Breslow completely neglects hydrogen bonding interactions, but since he only studied alcohol-water mixtures, the enforced hydrophobic interactions will dominate the behaviour. Recently, also Diels-Alder reactions in dilute salt solutions in aqueous ethanol have been studied and minor rate increases have been observed Lubineau has demonstrated that addition of sugars can induce an extra acceleration of the aqueous Diels-Alder reaction . Also the effect of surfactants on Diels-Alder reactions has been studied. This topic will be extensively reviewed in Chapter 4. 

All the early literature concerning thiazoles mentions numerous metallic complex-salts formed by addition to the thiazole of the aqueous solution of the metal salt and that could be used for identification purposes. The most usual complexes so obtained are platinum double salts, for example, (4-methylthiazole HC1)2 PtCU (m.p. deep 204°C) (25), or mercuric chloride derivatives, for example, 2,4-dimethyl-thiazole 2 HgCl (m.p. deep 176-177°C) (458). 

BackTitrations. In the performance of aback titration, a known, but excess quantity of EDTA or other chelon is added, the pH is now properly adjusted, and the excess of the chelon is titrated with a suitable standard metal salt solution. Back titration procedures are especially useful when the metal ion to be determined cannot be kept in solution under the titration conditions or where the reaction of the metal ion with the chelon occurs too slowly to permit a direct titration, as in the titration of chromium(III) with EDTA. Back titration procedures sometimes permit a metal ion to be determined by the use of a metal indicator that is blocked by that ion in a direct titration. Eor example, nickel, cobalt, or aluminum form such stable complexes with Eriochrome Black T that the direct titration would fail. However, if an excess of EDTA is added before the indicator, no blocking occurs in the back titration with a magnesium or zinc salt solution. These metal ion titrants are chosen because they form EDTA complexes of relatively low stability, thereby avoiding the possible titration of EDTA bound by the sample metal ion. 

In a back titration, a slight excess of the metal salt solution must sometimes be added to yield the color of the metal-indicator complex. Where metal ions are easily hydrolyzed, the complexing agent is best added at a suitable, low pH and only when the metal is fully complexed is the pH adjusted upward to the value required for the back titration. In back titrations, solutions of the following metal ions are commonly employed Cu(II), Mg, Mn(II), Pb(II), Th(IV), and Zn. These solutions are usually prepared in the approximate strength desired from their nitrate salts (or the solution of the metal or its oxide or carbonate in nitric acid), and a minimum amount of acid is added to repress hydrolysis of the metal ion. The solutions are then standardized against an EDTA solution (or other chelon solution) of known strength. 

Alkali or alkaline-earth salts of both complexes are soluble in water (except for Ba2[Fe(CN)g]) but are insoluble in alcohol. The salts of hexakiscyanoferrate(4—) are yellow and those of hexakiscyanoferrate(3—) are mby red. A large variety of complexes arise when one or more cations of the alkah or alkaline-earth salts is replaced by a complex cation, a representative metal, or a transition metal. Many salts have commercial appHcations, although the majority of industrial production of iron cyanide complexes is of iron blues such as Pmssian Blue, used as pigments (see Pigments, inorganic). Many transition-metal salts of [Fe(CN)g] have characteristic colors. Addition of [Fe(CN)g] to an unknown metal salt solution has been used as a quaUtative test for those transition metals. 

Iron (III) chloride hexahydrate [10025-77-17, FeCl36H2 0, is a brown-yeUow to orange material that crystallizes from a solution of iron or iron salt dissolved ia hydrochloric acid that coataias an oxidant such as Cfy or nitric acid. The monoclinic crystals contain the complex salt... 

Salt Formation and Metal Chelation, Most a-ainiao acids form salts in alkaline and acidic aqueous solutions (88). For example, a-amino acids form inner complex salts with copper. 

Solutions of anhydrous stannous chloride are strongly reducing and thus are widely used as reducing agents. Dilute aqueous solutions tend to hydrolyze and oxidize in air, but addition of dilute hydrochloric acid prevents this hydrolysis concentrated solutions resist both hydrolysis and oxidation. Neutralization of tin(II) chloride solutions with caustic causes the precipitation of stannous oxide or its metastable hydrate. Excess addition of caustic causes the formation of stannites. Numerous complex salts of stannous chloride, known as chlorostannites, have been reported (3). They are generally prepared by the evaporation of a solution containing the complexing salts. 

Copper hydroxide is almost iasoluble ia water (3 p.g/L) but readily dissolves ia mineral acids and ammonia forming salt solutions or copper ammine complexes. The hydroxide is somewhat amphoteric dissolving ia excess sodium hydroxide solutioa to form ttihydroxycuprate [37830-77-6] [Cu(011)3] and tetrahydroxycuprate [17949-75-6] [Cu(OH) ]. ... 

Dissolved oxygen reduction process Corrosion processes governed by this cathode reaction might be expected to be wholly controlled by concentration polarisation because of the low solubility of oxygen, especially in concentrated salt solution. The effect of temperature increase is complex in that the diffusivity of oxygen molecules increases, but solubility decreases. Data are scarce for these effects but the net mass transport of oxygen should increase with temperature until a maximum is reached (estimated at about 80°C) when the concentration falls as the boiling point is approached. Thus the corrosion rate should attain a maximum at 80°C and then decrease with further increase in temperature. 

A 0-9% salt solution is considered to be isotonic with blood. Other electrolytes present include bicarbonate ions (HCOj ) and small amounts of potassium, calcium, magnesium, phosphate, sulphate and organic acid ions. Included among the complex compounds and present in smaller amounts are phospholipids, cholesterols, natural fats, proteins, glucose and amino acids. Under normal conditions the extracellular body fluid is slightly alkaline with a pH of 7-4. ... 

Tantalum is severely attacked at ambient temperatures and up to about 100°C in aqueous atmospheric environments in the presence of fluorine and hydrofluoric acids. Flourine, hydrofluoric acid and fluoride salt solutions represent typical aggressive environments in which tantalum corrodes at ambient temperatures. Under exposure to these environments the protective TajOj oxide film is attacked and the metal is transformed from a passive to an active state. The corrosion mechanism of tantalum in these environments is mainly based on dissolution reactions to give fluoro complexes. The composition depends markedly on the conditions. The existence of oxidizing agents such as sulphur trioxide or peroxides in aqueous fluoride environments enhance the corrosion rate of tantalum owing to rapid formation of oxofluoro complexes. 

The process of separating the intermediate products from the purified solutions, in the form of solid complex fluoride salts or hydroxides, is also related to the behavior of tantalum and niobium complexes in solutions of different compositions. The precipitation of complex fluoride compounds must be performed under conditions that prevent hydrolysis, whereas the precipitation of hydroxides is intended to be performed along with hydrolysis in order to reduce contamination of the oxide material by fluorine. 

The great importance of the solubility product concept lies in its bearing upon precipitation from solution, which is, of course, one of the important operations of quantitative analysis. The solubility product is the ultimate value which is attained by the ionic concentration product when equilibrium has been established between the solid phase of a difficultly soluble salt and the solution. If the experimental conditions are such that the ionic concentration product is different from the solubility product, then the system will attempt to adjust itself in such a manner that the ionic and solubility products are equal in value. Thus if, for a given electrolyte, the product of the concentrations of the ions in solution is arbitrarily made to exceed the solubility product, as for example by the addition of a salt with a common ion, the adjustment of the system to equilibrium results in precipitation of the solid salt, provided supersaturation conditions are excluded. If the ionic concentration product is less than the solubility product or can arbitrarily be made so, as (for example) by complex salt formation or by the formation of weak electrolytes, then a further quantity of solute can pass into solution until the solubility product is attained, or, if this is not possible, until all the solute has dissolved. 

Determination of cobalt as cobalt tetrathiocyanatomercurate(II) (mercurithio-cyanate) Discussion. This method is based upon the fact that cobalt (II) in almost neutral solution forms a blue complex salt Co [ Hg( SCN )4] with a reagent... 

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