ISSN:
1572-8927
Keywords:
Activity coefficients
;
emf
;
hydrochloric acid
;
magnesium chloride
;
Pitzer's equations
;
Harned interaction coefficients
;
Brönsted-Guggenheim parameters
;
Higher-order electrostatic effects
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract Electromotive-force measurements have been made on HCl−MgCl2−H2O mixtures at 5, 15, 25, 35 and 45°C at eleven different ionic strengths from 0.1–5.0 mol-kg −1 . The results are interpreted in terms of the simple Harned's equations, as well as the more complicated Pitzer ion-component treatment of multicomponent electrolyte mixtures. Activity coefficients for HCl in the salt mixtures obey Harned's rule up to and including I=5.0. For the salt in the acid mixtures, Harned's rule holds true up to and including I=0.5. The contribution of higher-order electrostatic terms (Eθ and E'θ) in the Pitzer equations is important for accurate evaluations of unlike cation-cation interactions (θH,Mg), and cation-anion-cation interactions (ΨH,Mg,Cl). The values ofSθH,Mg and ΨH,Mg,Cl (determined with Eθ and E'θ), θH,Mg and ΨH,Mg,Cl (determined without Eθ and E'θ), as well as the trace activity coefficients of HCl, γ tr A , in solutions of MgCl2 (where ionic strength fraction of the salt,y B = 1) at all the experimental temperatures and ionic strengths, are reported. Results of this study are compared with those for similar systems. At I=0.1 and 25°C, the results of the Brönsted-Guggenheim specific interaction theory are discussed briefly.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00646403
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