Article

Abstract

As a foundation for a future measurement of solvated electron mobilities in alcohol-water mixed solvents, the electrical conductances of sodium tetraphenylboride (STPB) in methanol-water, ethanol-water, and 2-propanol-water were measured at different temperatures. The molar conductivity LAMBDA 0 (10-4 S m2 mol-1) of STPB at 298 K is 70 in pure water and 82 in pure methanol; in methanol-water mixed solvents it passes through a minimum, the value being 45 at 70 mol% water. In 2-propanol-water LAMBDA 0 (10-4 S m2 mol-1) at 298 K decreases rapidly from 70 in pure water to 22.6 in 80 mol% water, then gradually to 16.5 in pure 2-propanol. Behavior in ethanol-water is intermediate, with a minimum of 29.5 in 70 mol% water, gradually increasing to 35.5 in pure ethanol. The product of LAMBDA 0 and the solvent viscosity eta has a maximum at about 75 mol% water in methanol, 90 mol% water in ethanol, and 95 mol% water in 2-propanol. The effects are attributed to changes of solvent structure and of solvated ion radius as alcohol is added to water.Key words: alcohol-water mixed solvents, electrical conductivity, large ions, solvent effects, activation energy.

Solvent effects on reactivity of solvated electrons with ammonium nitrate in 2-propanol/water mixed solvents

“…The variation of E L 0 with solvent composition is qualitatively similar to that of E h . In the alcohol-rich region, E L 0 are considerably lower than E h , because the ions are less tightly solvated by alcohol molecules than by water molecules [1].…”

“…The studies of solvent effects on reactivity of solvated electrons (e À s ) with solutes have been carried out to elucidate solvated electrons behavior in nonhomogeneous fluids [1][2][3]. The solvated electrons were obtained by dissolving alkali metal in liquid ammonia, or other solvents [4,5].…”

Conductometric, spectrophotometric and thermodynamic studies of nickel sulfate in aqueous polyvinyl alcohol + methanol systems at different temperatures

“…The presence of a small amount of alcohol in water alters the solvent structure, by changing the hydrogen bond configurations. The addition of organic solvent to an aqueous solution of electrolyte brings about a change in ion solvation that often results in a large change in the reactivity of dissolved electrolyte [2][3][4][5][6][7].…”