SIT Parameters for the Dependence of (Poly)carboxylate Activity Coefficients on Ionic Strength in (C2H4)4NIaq(0 ≤I≤ 1.2 mol·kg-1) and (CH3)4NClaq(0 ≤I≤ 3.9 mol·kg-1) in the Temperature Range 278 K ≤T≤ 328 K and Correlation with Pitzer Parameters†

2007 ◽  
Vol 52 (6) ◽  
pp. 2195-2203 ◽  
Author(s):  
Francesco Crea ◽  
Concetta De Stefano ◽  
Claudia Foti ◽  
Silvio Sammartano
1990 ◽  
Vol 55 (8) ◽  
pp. 2001-2007
Author(s):  
Gurusamy Manivannan ◽  
Pichai Maruthamuthu

Aqueous thermal polymerization of acrylonitrile (AN) initiated by peroxomonosulphate (HSO5-, PMS)-thiolactic acid (TLA) and PMS-thiomalic acid (TMA) redox systems has been carried out in the temperature range 30-50 °C. The effect of concentration of monomer, initiator, reducing agent, H+, and ionic strength on rate of polymerization, Rp, has been investigated under deaerated conditions. The Rp has been found to depend on, Rp ~ [AN]01.5 [PMS]0.5 [TLA]0.5 in PMS-TLA system and, Rp ~ [AN]02.0 [PMS]1.0 [TMA]0 in PMS-TMA system. The degree of polymerization (Xn) values and thermodynamic parameters have been evaluated. Suitable reaction scheme has been proposed and expressions for Rp and Xn have been obtained.


1965 ◽  
Vol 20 (6) ◽  
pp. 1332-1336 ◽  
Author(s):  
Edward W. Moore ◽  
James W. Ross

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


2012 ◽  
Vol 65 (2) ◽  
pp. 113 ◽  
Author(s):  
Suprava Nayak ◽  
Gouri Sankhar Brahma ◽  
K. Venugopal Reddy

The formation of an intermediate ruthenium(iii) thiolate complex by the interaction of thiols, RSH (R = glutathione and l-cysteine) and dichlorotetraaquaruthenium(iii), [RuIIICl2(H2O)4]+, is reported in the temperature range 25–40°C. The kinetics and mechanism of formation of the intermediate complex were studied as a function of [RuIIICl2(H2O)4]+, [RSH], pH, ionic strength and temperature. Reduction of the intermediate complex takes place slowly and results in the corresponding disulfides RSSR and [RuIICl2(H2O)4]+. The results are interpreted in terms of a mechanism involving a rate-determining inner-sphere one-electron transfer from RSH to the oxidant used in the present investigation and a comparison of rate and equilibrium constants is presented with activation parameters.


2002 ◽  
Vol 38 (3-4) ◽  
pp. 237-247 ◽  
Author(s):  
W. Gierlotka ◽  
K. Fitzner ◽  
M. Sukiennik

The partial vapour pressure of mercury over liquid Hg-Tl liquid solutions were determined in the temperature range from 450 to 700 K by direct vapour pressure measurements carried out with the quartz gauge. From the measured ln pHg vs. T relationships activities of mercury were determined. Using Redlich-Kister formulas logarithms of the activity coefficients were described with the following equations: From which all thermodynamic functions in the solutions can be derived.


1993 ◽  
Vol 71 (3) ◽  
pp. 384-389 ◽  
Author(s):  
Stephen N. Smith ◽  
S. Sarada ◽  
Ramamurthy Palepu

The activity coefficients of NaNO3 in Mg(NO3)2, Ca(NO3)2, Sr(NO3)2 and Ba (NO3)2 were determined at constant total ionic strength of 0.1, 0.5, 0.75, 1.0, 1.5, and 2.0 mol kg−1 at 298 K using EMF methods. The experimental activity coefficients were analyzed using four different formalisms, namely, Reilly–Wood–Robinson, Scatchard, Pitzer, and Harned equations, and the interaction parameters were evaluated. Excess Gibbs free energy of mixing and trace activity coefficients were calculated and the results are discussed.


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