The Complete Calculation of Activity Coefficients from Freezing Point Data.

1933 ◽  
Vol 13 (1) ◽  
pp. 103-110 ◽  
Author(s):  
T. F. Young
Keyword(s):  
Activity Coefficients ◽  
Freezing Point ◽  
Complete Calculation ◽  
Point Data

PRODUCTION AND PROPERTIES OF 2,3-BUTANEDIOL: XII. ANTIFREEZE PROPERTIES OF TERNARY AQUEOUS SOLUTIONS CONTAINING LEVO-2,3-BUTANEDIOL AS A MAJOR COMPONENT

1946 ◽  
Vol 24f (5) ◽  
pp. 287-299 ◽  
Author(s):  
K. A. Clendenning ◽  
D. E. Wright
Keyword(s):  
Ethylene Glycol ◽  
Aqueous Solutions ◽  
Boiling Point ◽  
Freezing Point ◽  
Ternary Systems ◽  
Freezing Points ◽  
Point Depressant ◽  
Point Data ◽  
Considerable Range

Freezing point, viscosity, and boiling point data are presented for aqueous solutions of levo-2,3-butanediol containing methanol, ethanol, ethylene glycol, and tetrahydrofurfuryl alcohol as third components. All four ternary systems show freezing points of −50 °C. and lower over a considerable range of compositions. Among the compounds tested as third components, methanol was most effective as a thinning agent and accessory freezing point depressant. The data indicate that 20% methanol–40% butanediol–40% water is suitable for use at temperatures as low as −50 °C.

scholarly journals The accurate determination of the freezing-points of alloys, and a study of valency effects in certain alloys of silver

1937 ◽  
Vol 160 (901) ◽  
pp. 282-303 ◽  
Keyword(s):  
Freezing Point ◽  
Equilibrium Diagram ◽  
Accurate Determination ◽  
Freezing Points ◽  
Experimental Errors ◽  
Series Of Experiments ◽  
Point Data ◽  
Many Sources ◽  
Straight Lines

In the alloys of silver with the four elements immediately following it in the Periodic Table, the silver rich alloys give rise to primary substitutional solid solutions for which the phase boundaries in the equilibrium diagram show well-defined valency effects. When the diagrams are plotted in atomic percentages, the liquidus and solidus curves fall more steeply with increasing valency of the solute, whilst the extent of the solid solution becomes less. It was shown (Hume-Rothery, Mabbott and Channel-Evans 1934) that, to a first approximation, the liquidus curves followed a simple valency rule, such that alloys of identical equivalent composition had identical freezing-points, and, hence, in dilute solutions where the liquidus curves were straight lines, the atomic depression of freezing-point was proportional to the valency of the solute. The experimental errors of 1 or 2°C. in the freezing-point data prevented an exact proof of a whole number law, and the present paper describes more accurate determinations of the freezing-points of these alloys. The first part of the experimental work was carried out by one of the authors (W. H. -R.) working alone, and the later work by the two authors together. It is convenient to refer to the two series of experiments as the early work and the later work respectively. In order to increase the accuracy of the liquidus determinations it has been necessary to examine many sources of error, and this work is described in 2; 3 contains the experimental results, which are discussed in 4.

Na and K activity coefficients in bile and bile salts determined by glass electrodes

1964 ◽  
Vol 206 (5) ◽  
pp. 1111-1117 ◽  
Author(s):  
Edward W. Moore ◽  
John M. Dietschy
Keyword(s):  
Bile Salt ◽  
Activity Coefficients ◽  
Freezing Point ◽  
Osmotic Coefficients ◽  
Ionic Species ◽  
Salt Solutions ◽  
Glass Electrodes ◽  
Sodium And Potassium

Mathematical formulations for transmembrane potential differences are expressed in terms of ionic activities rather than ionic concentrations, and require knowledge of the activity coefficients of a given ionic species in mixed solutions. Cation-selective glass electrodes have been used to determine sodium and potassium activity coefficients in pure bile salt solutions and in native bile, relative to standard NaCl or KCl solutions. Comparison was made with osmotic coefficients determined by freezing-point depression. Both sodium and potassium activity coefficients in bile salt solutions and in bile were lower than those for NaCl or KCl solutions at corresponding concentrations, with potassium coefficients being lower than those for sodium. These derived activity coefficients have been used experimentally in in vivo and in vitro gall bladder preparations with close agreement between observed potentials and those predicted by the Hodgkin-Katz equation.

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