TY - JOUR
T1 - Activity coefficients of HCl + GdCl3 + H2O system from 5 to 55°C. Application of Pitzer formalism
AU - Roy, Rabindra N.
AU - Gregory, Darin R.
AU - Roy, Lakshmi N.
AU - Pierrot, Denis
AU - Millero, Frank J.
N1 - Funding Information:
The authors thank Andria Van Landuyt, Mousumi Kumar, Steve Gradney, Lily Tran, and Jay Howell for the preliminary measurements of this project. The Drury College group acknowledges the support of the Petroleum Research Fund, for partial support of this research through ACS-PRF Grant No. 333-44-B3. The Miami group acknowledges the support of the Oceanographic Section of the National Science Foundation.
PY - 2000/7
Y1 - 2000/7
N2 - The emf of the cell Pt, H2 (g, 1 atm) | HCl (mA), GdCl3 (mB) | AgCl, Ag without a liquid junction was used to investigate the HCl + GdCl3 + H2O mixed electrolyte system. The emf of the cell was measured for HCl + GdCl3 + H2O solutions at ionic strengths of 0.025, 0.05, 0.1, 0.5, 1.0, 1.5, and 2.0 mol-kg-1 and at eleven temperatures ranging from 5 to 55°C at 5°C intervals. The mean activity coefficients for HCl in the mixtures were determined using the Nernst equation. About 793 experimental emf data points were treated by the Harned equations. Results show that hydrochloric acid follows Harned's rule at all ionic strengths, but the quadratic term is needed for I = 1.5 mol-kg-1. The ion-interaction treatment of Pitzer was used to evaluate the results. The binary and ternary mixing parameters at 25°C were found to be ΘH,Gd = 0.07 ± 0.03 and ΨH,Gd,Cl = 0.14 ± 0.03. These values were determined using literature values of β(0), β(1), and Cφ for GdCl3 at 25°C and estimates of the effect of temperature from 5 to 55°C using enthalpy and heat capacity data.
AB - The emf of the cell Pt, H2 (g, 1 atm) | HCl (mA), GdCl3 (mB) | AgCl, Ag without a liquid junction was used to investigate the HCl + GdCl3 + H2O mixed electrolyte system. The emf of the cell was measured for HCl + GdCl3 + H2O solutions at ionic strengths of 0.025, 0.05, 0.1, 0.5, 1.0, 1.5, and 2.0 mol-kg-1 and at eleven temperatures ranging from 5 to 55°C at 5°C intervals. The mean activity coefficients for HCl in the mixtures were determined using the Nernst equation. About 793 experimental emf data points were treated by the Harned equations. Results show that hydrochloric acid follows Harned's rule at all ionic strengths, but the quadratic term is needed for I = 1.5 mol-kg-1. The ion-interaction treatment of Pitzer was used to evaluate the results. The binary and ternary mixing parameters at 25°C were found to be ΘH,Gd = 0.07 ± 0.03 and ΨH,Gd,Cl = 0.14 ± 0.03. These values were determined using literature values of β(0), β(1), and Cφ for GdCl3 at 25°C and estimates of the effect of temperature from 5 to 55°C using enthalpy and heat capacity data.
KW - Emf
KW - Gadolinium chloride
KW - Harned's rule
KW - Hydrochloric acid
KW - Mixtures of electrolytes
KW - Pitzer equations, activity coefficients
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U2 - 10.1023/A:1005129407455
DO - 10.1023/A:1005129407455
M3 - Article
AN - SCOPUS:0034349080
VL - 29
SP - 619
EP - 631
JO - Journal of Solution Chemistry
JF - Journal of Solution Chemistry
SN - 0095-9782
IS - 7
ER -