Non-electrolyte

J. J. Kipling, Adsorption from Solutions of Non-Electrolytes, Academic, New York, 1965. 

Experiments on sufficiently dilute solutions of non-electrolytes yield Henry s laM>, that the vapour pressure of a volatile solute, i.e. its partial pressure in a gas mixture in equilibrium with the solution, is directly proportional to its concentration, expressed in any units (molar concentrations, molality, mole fraction, weight fraction, etc.) because in sufficiently dilute solution these are all proportional to each other. 

Finally, a brief sunnnary of the known behaviour of activity coefficients Binary non-electrolyte mixtures ... 

The standard state of an electrolyte is the hypothetical ideally dilute solution (Henry s law) at a molarity of 1 mol kg (Actually, as will be seen, electrolyte data are conventionally reported as for the fonnation of mdividual ions.) Standard states for non-electrolytes in dilute solution are rarely invoked. 

The value of the second-order rate constant for nitration of benzene-sulphonic acid in anhydrous sulphuric acid varies with the concentration of the aromatic substrate and with that of additives such as nitromethane and sulphuryl chloride. The effect seems to depend on the total concentration of non-electrolyte, moderate values of which (up to about 0-5 mol 1 ) depress the rate constant. More substantial concentrations of non-electrolytes can cause marked rate enhancements in this medium. Added hydrogen sulphate salts or bases such as pyridine... 

GORDON, M., High Polymers—Structure and Physical Properties, Iliffe, London, 2nd Edn (1963) HILDEBRAND, J., and scoiT, R., The Solubility of Non-Electrolytes, Reinhold, New York, 3rd Edn (1949)... 

Non-electrolytic sources of hydrogen have also been studied. The chemical problem is how to transfer the correct amount of free energy to a water molecule in order to decompose it. In the last few years about I0(X)0 such thermochemical water-splitting cycles have been identified, most of them with the help of computers, though it is significant that the most promising ones were discovered first by the intuition of chemists. 

Sulfamide, (H2N)2S02, can be made by ammonolysis of SO3 or O2SCI2. It is a colourless crystalline material, mp 93°, which begins to decompose above this temperature. It is soluble in water to give a neutral non-electrolytic solution but in boiling water it decomposes to ammonia and sulfuric acid. The structure (Fig. 15.50c)... 

The Af-HjO diagrams present the equilibria at various pHs and potentials between the metal, metal ions and solid oxides and hydroxides for systems in which the only reactants are metal, water, and hydrogen and hydroxyl ions a situation that is extremely unlikely to prevail in real solutions that usually contain a variety of electrolytes and non-electrolytes. Thus a solution of pH 1 may be prepared from either hydrochloric, sulphuric, nitric or perchloric acids, and in each case a different anion will be introduced into the solution with the consequent possibility of the formation of species other than those predicted in the Af-HjO system. In general, anions that form soluble complexes will tend to extend the zones of corrosion, whereas anions that form insoluble compounds will tend to extend the zone of passivity. However, provided the relevant thermodynamic data are aveiil-able, the effect of these anions can be incorporated into the diagram, and diagrams of the type Af-HjO-A" are available in Cebelcor reports and in the published literature. 

Aqueous solutions of non-electrolytes, especially of non-polar solutes, may show the reverse effect and increase the proportions of ice-like components. The non-polar part of organic electrolytes such as soaps and wetting agents may predominate in increasing the ice component. Thus solutes can be divided into two classes structure making and structure breaking, and in some metal-finishing process solutions both types of solute may be added. 

Solubility of Non-electrolytes, J. H. Hildebrand. New York Reinhold Publishing Corp., 1936, p. 13. 

Aqueous solutions of many salts, of the common strong acids (hydrochloric, nitric and sulphuric), and of bases such as sodium hydroxide and potassium hydroxide are good conductors of electricity, whereas pure water shows only a very poor conducting capability. The above solutes are therefore termed electrolytes. On the other hand, certain solutes, for example ethane-1,2-diol (ethylene glycol) which is used as antifreeze , produce solutions which show a conducting capability only little different from that of water such solutes are referred to as non-electrolytes. Most reactions of analytical importance occurring in aqueous solution involve electrolytes, and it is necessary to consider the nature of such solutions. 

R. C. Pemberton and C. J. Mash. "Thermodynamic Properties of Aqueous Non-Electrolyte Mixtures II. Vapour Pressures and Excess Gibbs Energies for Water-)- Ethanol at 303.15 to... 

Some interesting results have been obtained by Akand and Wyatt56 for the effect of added non-electrolytes upon the rates of nitration of benzenesulphonic acid and benzoic acid (as benzoic acidium ion in this medium) by nitric acid in sulphuric acid. Division of the rate coefficients obtained in the presence of nonelectrolyte by the concentration of benzenesulphonic acid gave rate coefficients which were, however, dependent upon the sulphonic acid concentration e.g. k2 was 0.183 at 0.075 molal, 0.078 at 0.25 molal and 0.166 at 0.75 molal (at 25 °C). With a constant concentration of non-electrolyte (sulphonic acid +, for example, 2, 4, 6-trinitrotoluene) the rate coefficients were then independent of the initial concentration of sulphonic acid and only dependent upon the total concentration of non-electrolyte. For nitration of benzoic acid a very much smaller effect was observed nitromethane and sulphuryl chloride had a similar effect upon the rate of nitration of benzenesulphonic acid. No explanation was offered for the phenomenon. 

A useful equation for the calculation of liquid phase diffusivities of dilute solutions of non-electrolytes has been given by Wilke and CHANG(I6). This is not dimensionally consistent and therefore the value of the coefficient depends on the units employed. Using SI units ... 

Sontherland, W, A Dynamical Theory of Diffusion for Non-Electrolytes and the Molecnlar Mass of Albnmin, Philosophical Magazine 9, 781, 1905. 

Spectroscopic studies [118] of [Cu(5)Br2] suggest NNS coordination and a dimeric halogen bridged complex. This assignment is consistent with non-electrolytic behavior in DMF, but not with a magnetic moment at room temperature of 1.79 B.M. The shift of the thioamide 4 band from 815 cm" to 800 cm on complexation is taken as evidence for coordination of the... 

Acetylpyridine thiosemicarbazone forms [Co(8)2Cl2], which is isolated from hot ethanol [178], Based on infrared spectra the pyridyl nitrogen is coordinated and bonding is NS with two chlorines bringing the coordination number to six. The complex is a non-electrolyte in DMF, has a magnetic moment of 4.13 B.M., and the electronic spectrum has bands at about 8160 and 17 860 cm consistent with octahedral stereochemistry. 

Ethanol-dimethoxypropane solutions of either 1-formylisoquinoline or 2-formylquinoline thiosemicarbazone and cobalt(II) salts yield [Co(L)A2] complexes where A = Cl, Br, I, NO3, NCS, or NCSe [147]. All are non-electrolytes, have magnetic moments of 4.30-4.70 B.M. and are five coordinate with approximate trigonal bipyramidal stereochemistry involving NNS coordination based on electronic and infrared spectra. [Co(21-H)2] 2H2O was isolated from a cold methanolic solution of cobalt(II) chloride and 1-formylisoquinoline thiosemicarbazone [187]. Infrared spectral studies show NNS coordination the electronic spectral bands fit a distorted octahedral symmetry, and the magnetic moment is 4.48 B.M. 

Methyl-5-amino-l-formylisoquinoline thiosemicarbazone, 22, also yields cobalt(II) complexes from unheated methanol solution [202]. However, due to this ligand s added steric requirements, a complex, [Co(22)Cl2], with one ligand per metal ion center is formed. This brown solid has a magnetic moment of 4.42 B.M., is a non-electrolyte, has coordination of a neutral NNS ligand, and the electronic spectrum indicates approximate trigonal bipyramidal stereochemistry. 

Picolylphenylketone S-benzyldithiocarbazate, 48, yielded paramagnetic [ Ni(48-H)A 2] (A = Cl, Br) and diamagnetic [Ni(48-H)I] [207]. All three compounds are non-electrolytes and the iodo complex is planar while the other two complexes involve sulfur bridging atoms and five-coordinate nickel(II) centers. All three complexes can be converted to monomeric, octahedral complexes by addition of pyridine, 2-picoline or quinoline. 

Kamlet, M. J., Doherty, R. M., Carr, P., Abraham, M. H., Marcus, Y Taft, R. W. Linear solvation energy relationships. 46. An improved equation for correlation and prediction of octanol-water partition coefficients of organic non-electrolytes (including strong hydrogen bond donor solutes)./. Phys. Chem. 1988, 92, 5244-5255. 

Ti(R2 fc)3Cl is a seven coordinated monomeric species, as is suggested from the spectral data and the non-electrolytic character and confirmed by an X-ray diffraction study (6). Apart from the chlorine compounds the bromine analogues are reported (9). 

Activity coefficient models offer an alternative approach to equations of state for the calculation of fugacities in liquid solutions (Prausnitz ct al. 1986 Tas-sios, 1993). These models are also mechanistic and contain adjustable parameters to enhance their correlational ability. The parameters are estimated by matching the thermodynamic model to available equilibrium data. In this chapter, vve consider the estimation of parameters in activity coefficient models for electrolyte and non-electrolyte solutions. 

EM Wright, JM Diamond. Patterns of non-electrolyte permeability. Proc Royal Soc B 172 203-225, 1969. 

Thus, in weak electrolytes, molecules can exist in a similar way as in non-electrolytes—a molecule is considered to be an electrically neutral species consisting of atoms bonded together so strongly that this species can be studied as an independent entity. In contrast to the molecules of non-electrolytes, the molecules of weak electrolytes contain at least one bond with a partly ionic character. Strong electrolytes do not form molecules in this sense. Here the bond between the cation and the anion is primarily ionic in character and the corresponding chemical formula represents only a formal molecule nonetheless, this formula correctly describes the composition of the ionic crystal of the given strong electrolyte. 

The mean molality values m (moles per kilogram), mole fractions x (dimensionless number) and concentrations c (moles per cubic decimetre) are related by equations similar to those for non-electrolytes (see Appendix A). 

Similarly, concepts of solvation must be employed in the measurement of equilibrium quantities to explain some anomalies, primarily the salting-out effect. Addition of an electrolyte to an aqueous solution of a non-electrolyte results in transfer of part of the water to the hydration sheath of the ion, decreasing the amount of free solvent, and the solubility of the nonelectrolyte decreases. This effect depends, however, on the electrolyte selected. In addition, the activity coefficient values (obtained, for example, by measuring the freezing point) can indicate the magnitude of hydration numbers. Exchange of the open structure of pure water for the more compact structure of the hydration sheath is the cause of lower compressibility of the electrolyte solution compared to pure water and of lower apparent volumes of the ions in solution in comparison with their effective volumes in the crystals. Again, this method yields the overall hydration number. 

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