Solubility dissociation

Water solubility, dissociation constant(s) and n-octanol/water partition coefficients allow one to predict how an analyte may behave on normal-phase (NP), reversed-phase (RP), or ion-exchange solid-phase extraction (SPE) for sample enrichment and cleanup. 

Density, AGf, solubility, dissociation const, and standard potentials of oxidation-reduction reactions for aqueous species... 

The passage of electric current through a nonmetallic liquid is dependent on ions. The choice of electrolyte depends on such properties as its solubility, dissociation constant, mobility, discharge potential, and protic activity. It is desirable to employ a salt with high solubility, complete dissociation, high mobility of the ions, and a numerically high discharge potential. The role of adsorption of ions at the electrode is discussed elsewhere. The electrolyte may influence the rate constant for electron transfer from an electrode to a substrate. 

Chemical identity Physical-chemical data Melting point Boiling point Vapor pressure Water solubility Dissociation constant... 

Factors as proton activity, usable potential range, dielectric constant, ability to dissolve electrolytes and substrates, ion pair formation, vapour pressure, viscosity, toxicity (as regards the solvents) and solubility, dissociation constant, mobility and discharge potential (as regards the supporting electrolytes) must be carefully evaluated. 

Taking into account the equilibrium constants of the all processes mentioned in two nffichanisms (Khm, Ki, K.s, and Km and Kr2 are equilibrium constants for adsorption fi om a gas phase on the dry surface, adsorption of the ionic form, gas solubility, dissociation, and surface reaction constants), the total MM concentration in ad >rbed state (in molecular and ionic forms) cab be determined by the relationshrp [137] ... 

A series of nineteen 3 -(Oacyl) derivatives of etilefrine HCl was synthesized and dieir physical characteristics were evaluated. Correlations between structure and solubility, dissociation constant values, lipophUicity and esterase catalyzed hydrolysis were demonstrated. 3 -(OPivaloyl)-etilefrine showed favorable characteristics of solubility, lipophilicity and stability against enzymatic cleavage in blood."... 

Water produces this effect probably because dioxane is an acceptor for hydrogen ions thus producing the cations (I). On the other hand, hydroxyl ions transform dipicrylamine into the quinoidal anion (II). Consequently, the addition of water, which is shghtly dissociated into H+ and OH ions, results in the formation of the soluble dissociated orange-red salt of (I) and (II) ... 

The Fe(HC03)2 formed in this redox reaction is relatively soluble, dissociated and its formation is competing with the formation of insoluble iron(II) oxides such as Fe(OH)2 or colloidal associations such as Fe (OH) " [13]. 

In the case of a sparingly soluble salt that dissociates into v positive ions M and negative ions A, the solubility S is given by... 

Properties—Hydrogen iodide is a colourless gas. It is very soluble in water and fumes in moist air (cf. hydrogen chloride), to give hydriodic acid. Its solution forms a constant boiling mixture (cf. hydrochloric and hydrobromic acids). Because it attacks mercury so readily, hydrogen iodide is difficult to study as a gas, but the dissociation equilibrium has been investigated. 

Chromium(VI) oxide is very soluble in water initially, chromic acid , H2Cr04, may be formed, but this has not been isolated. If it dissociates thus ... 

In aqueous solution at 100° the change is reversible and equilibrium is reached when 95 per cent, of the ammonium cyanate has changed into urea. Urea is less soluble in water than is ammonium sulphate, hence if the solution is evaporated, urea commences to separate, the equilibrium is disturbed, more ammonium cyanate is converted into urea to maintain the equilibrium and evfflitually the change into urea becomes almost complete. The urea is isolated from the residue by extraction with boiling methyl or ethyl alcohol. The mechanism of the reaction which is generally accepted involves the dissociation of the ammonium cyanate into ammonia and cyanic acid, and the addition of ammonia to the latter ... 

Phenyldiazonium chloride and other similar diazonium compounds are very soluble in water, are completely insoluble in ether and other organic solvents, and are completely dissociated in aqueous solution to organic cations and inorganic anions (e.g., chloride ions) a convenient formulation is therefore, for example, CjHjNj+CP. 

Thia does not apply to aalta these are highly polar compounds, dissociate in solution In water, and are usually very soluble. 

In this experiment the equilibrium constant for the dissociation of bromocresol green is measured at several ionic strengths. Results are extrapolated to zero ionic strength to find the thermodynamic equilibrium constant. Equilibrium Constants for Calcium lodate Solubility and Iodic Acid Dissociation. In J. A. Bell, ed. Chemical Principles in Practice. Addison-Wesley Reading, MA, 1967. 

The physical properties of cyanoacetic acid [372-09-8] and two of its ester derivatives are Hsted ia Table 11 (82). The parent acid is a strong organic acid with a dissociation constant at 25°C of 3.36 x 10. It is prepared by the reaction of chloroacetic acid with sodium cyanide. It is hygroscopic and highly soluble ia alcohols and diethyl ether but iasoluble ia both aromatic and aUphatic hydrocarbons. It undergoes typical nitrile and acid reactions but the presence of the nitrile and the carboxyUc acid on the same carbon cause the hydrogens on C-2 to be readily replaced. The resulting malonic acid derivative decarboxylates to a substituted acrylonitrile ... 

Electrolytic Solvent. The use of DMAC as a nonaqueous electrolytic solvent is promising because salts are modesdy soluble ia DMAC and appear to be completely dissociated ia dilute solutions (18). 

Water-soluble peroxide salts, such as ammonium or sodium persulfate, are the usual initiators. The initiating species is the sulfate radical anion generated from either the thermal or redox cleavage of the persulfate anion. The thermal dissociation of the persulfate anion, which is a first-order process at constant temperature (106), can be greatly accelerated by the addition of certain reducing agents or small amounts of polyvalent metal salts, or both (87). By using redox initiator systems, rapid polymerizations are possible at much lower temperatures (25—60°C) than are practical with a thermally initiated system (75—90°C). 

Iron(III) bromide [10031-26-2], FeBr, is obtained by reaction of iron or inon(II) bromide with bromine at 170—200°C. The material is purified by sublimation ia a bromine atmosphere. The stmcture of inoa(III) bromide is analogous to that of inon(III) chloride. FeBr is less stable thermally than FeCl, as would be expected from the observation that Br is a stronger reductant than CF. Dissociation to inon(II) bromide and bromine is complete at ca 200°C. The hygroscopic, dark red, rhombic crystals of inon(III) bromide are readily soluble ia water, alcohol, ether, and acetic acid and are slightly soluble ia Hquid ammonia. Several hydrated species and a large number of adducts are known. Solutions of inon(III) bromide decompose to inon(II) bromide and bromine on boiling. Iron(III) bromide is used as a catalyst for the bromination of aromatic compounds. 

Lead Sesquioxide. Lead sesquioxide (lead trioxide), Pb202, is an amorphous, orange-yeUow powder soluble ia cold water. It decomposes ia hot water and ia acids to lead salts plus Pb02. Lead sesquioxide can be prepared from lead dioxide by hydrothermal dissociation (43). 

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