Autoprotolysis constants and activity ratios of the lyate ions in water-alcohol mixtures

Abstract

The autoprotolysis constants were determined potentiometrically for water-ethanol, water-1-propanol, water-2-propanol, and water-2-methyl-2-propanol mixtures containing alcohol in concentrations of 60% (m/m) and more. Three methods were employed for the calculation of the activity ratios of the lyate ions in the systems: an empirical method based on the autoprotolysis constant and the activities of the solvent constituents, a method based on thermodynamic data, particularly the Gibbs energies of ion transfer from water to the mixed solvent, and a method based on 1H NMR data. The results of the three methods are mutually compared and discussed. The known heats of ionization for the water-ethanol system and the ionization constants of the components enabled the entropy of ionization of a mixture of water with ethanol to be calculated.

Sensitized photolysis of polychlorobiphenyls in alkaline 2-propanol: dechlorination of Aroclor 1254 in soil samples by solar radiation

“…contribution to the overall kinetics of the chain reaction is insignificant (19). In contrast to Nishiwaki (13), we thus believe that the ketyl radical, (CH3)2C'OH, reacts with the hydroxyl anion, OH-, rather than with the 2-propoxide anion, (CH3)2CHO-, to give (CH,),CO'-.…”

Ratio of lyate ions activities in two-components protogenic solvents

“…It is apparent that, except for 10 wt. % ethanol, the agreement between the ionization constants of ethanol calculated from the literatllre data 2 by means of Eqs (2) and (3) is good. Autoprotolysis constants of water in mixtures z ,z6,29 were used for the evaluation of the ratio of lyate activities according to Eq.…”

Photoluminescence Detection of Surface Oxidation Processes on InGaN/GaN Nanowire Arrays

“…Here, we confine our investigations to pure hydrocarbons and to alcohols with C1 to C3 chain lengths. Among the wide variety of functional groups that can abound on hydrocarbon cores, OH functional groups appeared to be of particular interest as alcohols, similar to water vapor, can support autoprotolysis reactions of the form , ­(R: hydrocarbon backbones; OH, O – , OH 2 + : functional groups) which suggests that these species might give rise to a similarly complex PL response behavior as adsorbed water vapor. In contrast to this expectation we find that all kinds of hydrocarbons do give rise to surprisingly similar PL response behavior, namely, PL enhancement when InGaN/GaN NWAs are operated at elevated temperature and in chemically reactive synthetic air (SA) environments but not in chemically inert N 2 backgrounds.…”

“…Here, we confine our investigations to pure hydrocarbons and to alcohols with C1 to C3 chain lengths. Among the wide variety of functional groups that can abound on hydrocarbon cores, OH functional groups appeared to be of particular interest as alcohols, similar to water vapor, can support autoprotolysis reactions of the form 20,21…”