Activity coefficients of NaCl in NaCl–NaOAc–H2O at 25, 35, and 45 °C

1991 ◽  
Vol 69 (1) ◽  
pp. 111-115 ◽  
Author(s):  
S. Manohar ◽  
J. Ananthaswamy
Keyword(s):  
Sodium Chloride ◽  
Key Words ◽  
Activity Coefficients ◽  
Sodium Acetate ◽  
Osmotic Coefficients ◽  
Free Energies ◽  
Harned's Rule ◽  
Pitzer Formalism ◽  
Scatchard Equation

The activity coefficients of NaCl were estimated by measuring the EMFs of the cell[Formula: see text]at four ionic strengths, i.e., 0.5, 1.0, 2.0, and 3.0 mol/kg and at temperatures 25, 35, and 45 °C. The results were analyzed in terms of Harned's rule, the Pitzer and Rush–Johnson–Scatchard treatments. Osmotic coefficients and excess free energies of mixing were calculated at all ionic strengths and temperatures studied. Key words: activity coefficients, sodium chloride, sodium acetate, Pitzer formalism, Scatchard equation.

Osmotic coefficients and activity coefficients of aqueous mixtures of sodium chloride and sodium carbonate at 25°C

1980 ◽  
Vol 33 (9) ◽  
pp. 1903 ◽  
Author(s):  
Jr DR White ◽  
RG Bates
Keyword(s):  
Sodium Chloride ◽  
Activity Coefficients ◽  
Sodium Carbonate ◽  
Osmotic Coefficients ◽  
Pitzer Equation ◽  
Aqueous Mixtures ◽  
Free Energies ◽  
Scatchard Equation ◽  
The Individual ◽  
Reference Electrolyte

Isopiestic vapour-pressure measurements have been used to determine the osmotic coefficients of aqueous mixtures of sodium chloride and sodium carbonate at 25°C. Solutions of sodium chloride were used as the reference electrolyte. The data served to evaluate the excess free energies of mixing as well as the mixing parameters of the Scatchard and Pitzer theories. The three-parameter form of the Scatchard equation accounts well for the experimental results, and the Pitzer equation with two adjustable parameters does equally well. The activity coefficients of the individual salts in the mixtures have been calculated.

NaCl and CaCl2 activity coefficients in mixed aqueous solutions

1965 ◽  
Vol 20 (6) ◽  
pp. 1332-1336 ◽  
Author(s):  
Edward W. Moore ◽  
James W. Ross
Keyword(s):  
Ionic Strength ◽  
Activity Coefficients ◽  
Technical Assistance ◽  
Osmotic Coefficients ◽  
Electrode System ◽  
Glass Electrode ◽  
Concentration Data ◽  
Harned's Rule ◽  
Potentiometric Measurement

In the investigation of numerous physiological phenomena it is the activity of an ion species which is desired, rather than stoichiometric concentration. The calculation of mean ionic activity from known concentration data requires accurate activity coefficients (ggr). This report concerns the determination of ggrNaCl and ggrCaCl2 in mixed NaCl-CaCl2 solutions by potentiometric measurement with a sodium-selective glass electrode-Ag/AgCl electrode system over the ionic strength range 0.05–0.5 m. Log ggrNaCl varied linearly, at constant total ionic strength, with the ionic strength of CaCl2 in the mixture, in accordance with Harned's rule. From data thus obtained, ggrCaCl2 coefficients in such mixed solutions have been calculated and compared with values calculated from published osmotic data. Resulting activity coefficient curves for ggrCaCl2 are presented over the concentration range encountered in serum and other extracellular fluids. Note: (With the Technical Assistance of Leonard Kaye and Leonard L. Anderson) glass electrodes; ion interaction; electrolyte metabolism; Harned's rule; membrane transport; osmotic coefficients Submitted on March 11, 1965

Thermodynamics of electrolyte solutions: activity coefficients of NaCl in the NaCl–NiCl2–H2O system at 25, 35, and 45 °C

1990 ◽  
Vol 68 (2) ◽  
pp. 294-297 ◽  
Author(s):  
Ch. Venkateswarlu ◽  
J. Ananthaswamy
Keyword(s):  
Activity Coefficients ◽  
Silver Chloride ◽  
Osmotic Coefficients ◽  
Reference Electrode ◽  
Nickel Chloride ◽  
Electrolyte Solutions ◽  
Pitzer Formalism ◽  
Harned Coefficients ◽  
Silver Silver ◽  
Silver Silver Chloride

The activity coefficients of NaCl in the NaCl–NiCl2–H2O system were estimated at 25, 35, and 45 °C and total ionic strengths of 0.5, 1.0, 2.0, and 3.0 m by an EMF method using a Na-ion selective electrode and a silver–silver chloride reference electrode. The Harned coefficients were calculated at all the temperatures studied. At 25 °C the data were analysed using the Pitzer formalism. The osmotic coefficients and the excess free energies of mixing were also calculated at 25 °C. Keywords: activity coefficients, sodium chloride, nickel chloride, Pitzer equations, thermodynamics.

Activity Coefficients of (Hydrogen Chloride + Europium Chloride) (aq) Using Harned's Rule and the Pitzer Formalism

2001 ◽  
Vol 46 (3) ◽  
pp. 551-556 ◽  
Author(s):  
Rabindra N. Roy ◽  
Lakshmi N. Roy ◽  
Darin Gregory ◽  
Andria VanLanduyt ◽  
Denis Pierrot ◽  
...  
Keyword(s):  
Hydrogen Chloride ◽  
Activity Coefficients ◽  
Harned's Rule ◽  
Pitzer Formalism ◽  
Europium Chloride

Determination of water activity, osmotic coefficients, activity coefficients, solubility and excess Gibbs free energies of NaCl-sucrose-H2O mixture at 298.15 K

2019 ◽  
Vol 284 ◽  
pp. 492-501 ◽  
Author(s):  
Brahim Messnaoui ◽  
Abdelfetah Mounir ◽  
Abderrahim Dinane ◽  
Abderrahim Samaouali ◽  
Bahija Mounir
Keyword(s):  
Water Activity ◽  
Activity Coefficients ◽  
Osmotic Coefficients ◽  
Free Energies

Osmotic and activity coefficients of triorganophosphates in n-octane

1982 ◽  
Vol 60 (22) ◽  
pp. 2755-2759 ◽  
Author(s):  
Norman H. Sagert ◽  
Danny W. P. Lau
Keyword(s):  
Thermodynamic Properties ◽  
Vapor Pressure ◽  
Activity Coefficients ◽  
Osmotic Coefficients ◽  
Vapor Pressure Osmometry ◽  
Excess Enthalpies ◽  
Free Energies ◽  
Ideal Behavior ◽  
Excess Thermodynamic Properties ◽  
Complex Models

Vapor pressure osmometry was used to measure osmotic coefficients for tributylphosphate (TBP), tricresylphosphate (TCP), and triethylhexylphosphate (TEHP) in n-octane at 30, 40, 50, and 60 °C and at molalities up to 0.3 mol/kg. Activity coefficients and excess thermodynamic properties (unsymmetrical definition) were calculated from these osmotic coefficients. At 30 °C, the excess Gibbs free energies for 0.1 mol of solute in 1.0 kg n-octane were −42 J, −66 J, and −20 J for TBP, TCP, and TEHP, respectively. The more ideal behavior of the TEHP-octane system is attributed to the increasing importance of hydrocarbon–hydrocarbon interactions as the chain length is increased. The excess enthalpies for 0.1 mol of solute in 1.0 kg of solvent were −100 J, −300 J, and −150 J for TBP, TCP, and TEHP, respectively. Thus, association of these solutes arises primarily from entropie effects.Our data could generally be accommodated adequately by postulating association of monomers into dimers. The exception was TCP at lower temperatures, where more complex models were required.

Thermodynamic properties of multicomponent electrolyte solutions in mixed solvents. 5• HCl + NaCl + urea + water at 278.5–318.15 K

1988 ◽  
Vol 66 (4) ◽  
pp. 637-644 ◽  
Author(s):  
Dian-Yuan Men ◽  
Jia-Zhen Yang ◽  
Chun-Yu Liang ◽  
Li-Tian Zhang ◽  
Huan Gao ◽  
...  
Keyword(s):  
Mixed Solvents ◽  
Electrolyte Solutions ◽  
Absolute Temperature ◽  
Molar Enthalpy ◽  
Free Energies ◽  
Force Measurements ◽  
Solution Theory ◽  
Electrolytic Solution ◽  
Harned's Rule ◽  
Electromotive Force Measurements

This paper reports electromotive force measurements of the cells[Formula: see text]and[Formula: see text]in mixed solvents of urea, mole fraction x = 0.05, at five temperatures from 278.15 to 318.15 K. The standard potentials of Ag–AgCl electrode in mixed solvents were obtained from the emf of cell (A) for HCl of molality mA from 0.02 to 0.11 mol kg−1, both by extrapolation on the basis of an extended Debye–Hückel equation and by a polynomial approach proposed in this paper on the basis of Pitzer's electrolytic solution theory. The standard free energies of transfer for HCl are discussed. The activity coefficients of HClγA in HCl + NaCl + urea + water have also been obtained from the emf of cell (B) at constant total ionic strength I = 0.5, 1.0, 1.5, and 2.0 mol kg−1. The experimental results show that HCl obeys Harned's rule and log γA is a linear function of absolute temperature T. They also indicate that the relative partial molar enthalpy of HCl obeys a similar Harned's rule.

Sign in / Sign up

Export Citation Format

Share Document