Colloid formation chloride

The pH at which basic iron(III) formate begins to precipitate depends upon several factors, which include the initial iron and chloride concentration a high concentration of ammonium chloride is essential to prevent colloid formation. It is important to use an optimum initial pH to avoid a large excess of free acid, which would have to be neutralised by urea hydrolysis, and yet there must be present sufficient acid to prevent the formation of a gelatinous precipitate prior to boiling the solution ideally, a turbidity should appear about 5-10 minutes... 

The active ingredient is sodium pyrophosphate (Na4P20ylO H2O). For reduction of Tc-pertechnetate to lower oxidation states, tin(II) chloride or tin(II) fluoride is used. An optimal ratio of reducing agent/pyrophosphate must be maintained to prevent Tc-Sn-colloid formation (Srivastava et al. 1977). Technical problems with kit production have been reported (Kowalsky and Dalton 1981). 

Important objectives of the later prodnction methods were to control the size and shape of the catalyst particles during precipitation of the magnesium chloride and to improve stabihty. Catalysts with better-controlled size and shape were based on the reaction of a precipitated magnesium chloride with titanium tetrachloride in a high-boiling-point hydrocarbon diluent at 80°C, with di-isobutyl phthalate added as an internal electron donor. " After separation, the sohd formed was reacted with more titaninm tetrachloride at 120°C, before being washed and dried. The catalyst contained between 2-3% titanium and the phthalates used were hmited to C4-C8 esters to avoid potential problems with colloid formation. The catalysts prodnced with phthalates as the internal donor had mnch higher snrface area and pore volume than when ethyl berrzoate was nsed. This method provided more active arrd stereospecifrc catalysts when used with the same triethyl aluminum co-calalyst and an external electron donor such as phenyl triethoxy silane. 

Palladium catalysts have been prepared by fusion of palladium chloride in sodium nitrate to give palladium oxide by reduction of palladium salts by alkaline formaldehyde or sodium formate, by hydrazine and by the reduction of palladium salts with hydrogen.The metal has been prepared in the form of palladium black, and in colloidal form in water containing a protective material, as well as upon supports. The supports commonly used are asbestos, barium carbonate, ... 

A substitute may be prepared thus 0 05 gram palladous chloride is placed in a special shaking flask with 50 c.c, of 50 per cent, alcohol and 1 or 2 c c. of 1 per cent, aqueous solution of gum-arabic, the weight of gum being about one-fourth the weight of the palladous chloride. On shaking this mixture in an atmosphere of hydrogen the chloride is reduced with formation of a black solution of colloidal platinum, which is rendered stable by the small quantity of gum present. 

Non-Aqueous Colloidal Metal Solutions. It has been difficult to prepare colloidal gold in non-aqueous media due to limitations in preparative methods (low salt solubilities, solvent reactivity, etc.), and the fact that the low dielectric constant of organic solvents has hindered stabilization of the particles. In aqueous solution the gold particles are stabilized by adsorption of innocent ions, such as chloride, and thus stabilized toward flocculation by the formation of a charged double layer, which is dependent on a solvent of high dielectric constant. Thus, it seemed that such electronic stabilization would be poor in organic media. 

Intravenous administration of 1 mg of yttrium chloride to rats caused formation of colloidal material in blood plasma, which accumulated primarily in the liver and spleen causing injury to these organs. ... 

Water treatment by either direct or contact filtration has become common practice for raw water with low turbidity [<3NTU] and low colour. Simple metal salts such as alum or ferric chloride are added to plant inlet water. Hydrolysis takes place with the formation of hydroxylated species, which adsorb, reducing or neutralizing the charge on the colloidal particles in the raw water, promoting their collision and the formation of floes that settle or can be filtered out. 

Hydrolysis of FeCf Solutions. Aging of ferric chloride solutions yields, as a rule, either colloidal akageneite (p-FeOOH) or hematite (a-Fe203). However, the two forms are closely related in the formation of the precipitates (95,142). 

Foam properties related to salt. The addition of sodium chloride to soybean protein suspensions caused them to form high-capacity, low-stability foams (13). It was suggested that foam capacity increased because salt improved protein solubility at the interface of the colloidal suspension during foam formation, but retarded the partial denaturation of the surface polypeptides of proteins that are necessary for protein-protein interaction and stability. 

The position of the ASV peak on the voltage scan reflects the nature of the ion being reduced, and for complex ions the peak position moves to more negative potentials as stability increases. In some cases formation of intermediate valency states (e.g. in chloride solution, Cu2+ — Cu+ — Cu°) results in split peaks. Adsorption of species (e.g. colloidal particles, surfactants) on the mercury electrode also causes peak movement (generally in an anodic direction). 

Finally, our recent research work has demonstrated that hazardous compounds can be formed in the presence of the nitrating agent N02, arising from nitrate photolysis or nitrite oxidation [88-91], and the chlorinating Cl2 " [92], Formation of the latter from OH and CD can only take place in acidic solution, but chloride oxidation is, for instance, possible upon charge-transfer processes in the presence of irradiated Fe(III) oxide colloids (represented as =Fe3+—OH in Equation 17.32) [93],... 

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