Browsing by Author "Feakins, David"

Filter results by typing the first few letters
Now showing 1 - 3 of 3
  • No Thumbnail Available
    Item
    Transition State Treatment of the Relative Viscosity of Electrolytic Solutions: Applications to Aqueous, Non-aqueous and Methanol + Water Systems
    (Journal of the Chemical Society : Faraday Transaction - I. The Chemical Society, London. 1974, 70 (1-6), 1974) Feakins, David; Freemantle, David J.; Lawrence, Kenneth G.
    A transition-state treatment of the relative viscosity of electrolyte solutions is described. The following expression is found for the viscosity B-coefficient: B=(V°1–V°2)/1000 +V°1[(Δµ°[graphic omitted]2–Δµ°[graphic omitted]1)/1000 RT]. V°1 and V°2 are the partial molal volumes of the solvent and solute respectively; Δµ°[graphic omitted]1 is the activation energy for viscous flow of the solvent, and Δµ°[graphic omitted]2 the “ionic activation energy” at infinite dilution. For aqueous solutions, at 25°C, the term (V°1–V°2)/1000 accounts completely, in the case of ammonium chloride, and partially in the case of potassium, rubidium and caesium chlorides, for the negative sign of the B-coefficient. When solutions in different solvents are compared, the well-known tendency for B to increase with V°1 is at least partly explained by the form of the above expression; changes in µ°[graphic omitted]2 from water to methanol, for example, are less dramatic than changes in B. B-coefficients in the methanol + water system are consistent with a maximum in solvent structure around 20% methanol (w/w) at 25°C; whilst the µ°[graphic omitted]2-values support this interpretation, it is noted that solvent structure can influence B twice over, in µ°[graphic omitted]2 and (trivially) in µ°[graphic omitted]1.
  • No Thumbnail Available
    Item
    Washburn numbers: Part 1.—The electromotive force method for alkali-metal chlorides in the methanol + water and dioxan + water systems
    (Journal of the Chemical Society : Faraday Transaction - I. The Chemical Society, London. 1974, 70 (10), 1974) Feakins, David; Lorimer, John Phillip
    The e.m.f. method has been used to study the transport of water in solutions of alkali-metal chlorides in methanol + water and dioxan + water systems. A detailed description of the method is given. Specimen results indicate a dependence of the Washburn number of water wW° on solvent structure.
  • No Thumbnail Available
    Item
    Washburn Numbers: Part 3.—Alkali-metal Chlorides in the DMSO4-Water System; Comparison with Hydrochloric Acid ; “ Structural ” Effects
    (Journal of the Chemical Society : Faraday Transaction - I. The Chemical Society, London. 1978, 74 (02), 1978) Feakins, David; O’Shaughnessy, Denis A.
    Washburn numbers for alkali-metal chlorides have been measured in the range 0-40 % (w/w) DMSO (x2 = 0-0.094) and are compared with literature values for H+CI-. There is evidence for significant incorporation of DMSO into near-neighbour shells of H+ and Li+; by making certain assumptions it is concluded that these ions, and Cl-, are preferentially solvated by DMSO. The Washburn numbers of H+Cl, LrCl- and K+Cl- show maxima when plotted against ,v2. Possible explanations of this behaviour, which is paralleled by that of the Walden products, are discussed in detail, and it is concluded that it arises mainly from shifts in the preferential rather than the total solvation of the ions. The maxima in are evidence for the retention of water-like structure in the region studied, but not necessarily for its enhancement.