Osmotic and activity coefficients in dilute solutions of ethanol in cyclohexane from freezing-point measurements

1974 ◽  
Vol 3 (8) ◽  
pp. 671-681 ◽  
Author(s):  
R. H. Stokes
Keyword(s):  
Activity Coefficients ◽  
Freezing Point ◽  
Dilute Solutions

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.

Molten salts freezing point measurements in the AgNO3-AgCl system

1966 ◽  
Vol 19 (9) ◽  
pp. 1597 ◽  
Author(s):  
R Jacoud ◽  
VC Reinsborough ◽  
FEW Wetmore
Keyword(s):  
Silver Nitrate ◽  
Activity Coefficients ◽  
Molten Salts ◽  
Formation Constant ◽  
Freezing Point ◽  
Complex Cation

Activities of silver nitrate in the AgNO3-AgCl system were obtained through freezing point depressions. Activity coefficients were calculated assuming the melt consisted of only simple ions which mixed ideally and then assuming the chloride was totally in the form of the complex cation, Ag2Cl+, which also mixed ideally. The second model proved more successful and was extended to include Ag+Cl- entities in the melt. A formation constant of 12�2 was obtained for Ag2Cl+ at 210�.

scholarly journals VIII. The ionization of dilute solutions at the freezing point

1900 ◽  
Vol 194 (252-261) ◽  
pp. 321-360 ◽  
Keyword(s):  
Potassium Chloride ◽  
Electric Current ◽  
Sulphuric Acid ◽  
Electric Charge ◽  
Chemical Nature ◽  
Freezing Point ◽  
Barium Chloride ◽  
The Other ◽  
Dilute Solutions ◽  
The Subject

The existence of a relation between the depression of the freezing point, produced by dissolving an acid or a salt in water, and the electrolytic conductivity of the solution thus obtained was pointed out by Arrhenius in 1887, and has been the subject of much experiment and discussion since that date. As is well known, the facts of electrolysis indicate that an electric current, when passing through a solution, is associated with a passage in opposite directions of the constituents of the salt. Faraday called these mobile parts ions. The number of the ions depends on the chemical nature of the salt, and is usually indicated by its formula. Thus for one molecule of potassium chloride we have two ions, the potassium travelling in one direction and the chlorine in the other. For barium chloride or sulphuric acid we have three ions, and, since the electric charge of an ion is proportional to its valency, the electrically equivalent weights of these substances are represented by ½BaCl 2 and ½H 2 So 4 , respectively.

scholarly journals The ionisation of dilute solutions at the freezing point

1900 ◽  
Vol 66 (424-433) ◽  
pp. 192-203 ◽  
Keyword(s):  
Electrical Conductivity ◽  
Freezing Point ◽  
Dilute Solutions ◽  
Electrical Conductivities

It is known that the depression of the freezing point of water, pro­duced by dissolving molecularly equivalent amounts of different acids and salts in a given quantity of it, is approximately proportional to the number of ions which these substances must be supposed to yield in order to explain their electrical conductivities. Again, as the con­centration of a solution of one such substance is gradually increased, the molecular depression of the freezing point, and the equivalent electrical conductivity, both vary, and vary by amounts which seem in some cases to correspond, but in others to differ considerably.

The electrical conductivity of solutions at the freezing-point of water

1903 ◽  
Vol 71 (467-476) ◽  
pp. 332-338 ◽  
Keyword(s):  
Electrical Conductivity ◽  
Royal Society ◽  
Freezing Point ◽  
Dilute Solutions ◽  
Freezing Points ◽  
Solvent Action

The following paper contains an account of experiments which bring to greater concentrations the series of measurements on the conductivities of dilute solutions at the freezing point, communicated to the Royal Society in February, 1900. The work has been carried on at intervals during the last two years, and was made possible by the kindness of Professor Ewing, who placed a room at the Cambridge Engineering Laboratory at the disposal of the writer and his wife. The earlier experiments were originally planned in connection with the observations undertaken by Dr. E. H. Griffiths on the freezing points of corresponding solutions; they were therefore conducted in a platinum cell of design similar to that used by Griffiths, with the object of eliminating any solvent action of glass. Any such action would be quite inappreciable at the concentrations used in the experiments now to be described; resistance cells of glass were consequently used, and the labour of observation was much reduced.

scholarly journals The depression of freezing point in very dilute aqueous solutions

1910 ◽  
Vol 83 (565) ◽  
pp. 454-461 ◽  
Keyword(s):  
Aqueous Solutions ◽  
Osmotic Pressure ◽  
Royal Society ◽  
Unit Volume ◽  
Freezing Point ◽  
Dilute Solutions ◽  
Dilute Aqueous Solutions ◽  
Similar Solutions

1. According to the ionisation theory, both the depression of the freezing point and the conductivity of a solution of an electrolyte are connected with the ionisation of the solute, and conclusions as to the degree of ionisation in dilute solutions may be drawn from both phenomena, on certain assumptions. The experiments on the depression of the freezing point of very dilute solutions, described in the paper, were planned in connexion with measurements of the conductivity of similar solutions which were made by Mr. W. C. D. Whetham, F. R. S., and have been described in papers communicated to the Royal Society in 1900 and 1902. It was intended to compare the conclusions, drawn from the results of the associated researches, as to the degree of ionisation of the solutions, especially at great dilution. If it be assumed that each molecule which dissociates in solution yields i ions, and that the osmotic pressure is equal to the pressure, according to the simple laws of gases, existing in a gas having the same number of molecules per unit volume as there are molecules and ions in unit volume of the solution, then the coefficient of ionisation (the proportion of molecules ionised in the solution) is given by α = ∆δ/δ( i -1).

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