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  • 1
    Electronic Resource
    Electronic Resource
    Dissociation constant of acetic acid in N-methylpropionamide from 5 to 55°C and related thermodynamic quantities (1972)
    Springer
    Journal of solution chemistry 1 (1972), S. 507-516 
    Details
    ISSN: 1572-8927
    Keywords: Acetic acid ; dissociation constant ; N methylpropionamide ; nonaqueous solvents ; solute-solvent interactions ; weak acids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The dissociation constant of acetic acid in N-methylpropionamide (NMP) has been determined at 11 temperatures from 5 to 55°C by measurement of the electromotive force of cells without liquid junction containing hydrogen gas electrodes and silver-silver chloride electrodes. The pK at 25°C was found to be 7.995 (molal scale) as compared with 4.756 in water; thus, acetic acid is much weaker in NMP than in water despite the higher dielectric constant of the nonaqueous solvent (176 as compared with 78.3 at 25°C). The standard changes of enthalpy and entropy for the dissociation of acetic acid were calculated from the temperature coefficient of pK, and thermodynamic functions for the transfer dissociation process were obtained. The weakness of acetic acid in NMP is discussed in terms of electrostatic effects and solute-solvent interactions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00651727
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  • 2
    Electronic Resource
    Electronic Resource
    Dissociation constant of protonated tris(hydroxymethyl)aminomethane in N-methylpropionamide and related thermodynamic quantities from 10 to 55°C (1973)
    Springer
    Journal of solution chemistry 2 (1973), S. 405-415 
    Details
    ISSN: 1572-8927
    Keywords: Acidic dissociation ; dissociation constant ; emf measurements ; ionization processes ; N-methylpropionamide ; solvation ; tris-(hydroxymethyl)aminomethane
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The dissociation constant of protonated tris(hydroxymethyl)aminomethane (tris·H+) in the solvent N-methylpropionamide (NMP) has been determined at intervals of 5°C from 10 to 55°C by measurement of the emf of cells without liquid junction using hydrogen and silver-silver chloride electrodes. At 25°C, pK a was found to be 8.831, as compared with 8.075 in water. The standard changes in Gibbs energy, enthalpy, and entropy for the dissociation process have been evaluated from the dissociation constant and its change with temperature. By comparison with similar data for the dissociation of tris·H+ in water, thermodynamic functions for the transfer from water to NMP have been derived. The dissociation process is isoelectric, and the solvent dielectric constant is high (ε=176 at 25°C). Consequently, electrostatic charging effects are expected to be minimal, and the change in dissociation constant depends primarily on solute-solvent interactions. The results, combined with transfer energies for HCl, tris, and tris·HCl from emf and solubility measurements, demonstrate that the decreased acidic strength of tri·H+ in NMP is attributable in large part to the fact that NMP is less effective than water in stabilizing tris and its salts.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00713253
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  • 3
    Electronic Resource
    Electronic Resource
    Activity coefficient of hydrochloric acid in aqueous solutions of sodium chloride (1977)
    Springer
    Journal of solution chemistry 6 (1977), S. 385-392 
    Details
    ISSN: 1572-8927
    Keywords: Activity coefficient ; electrolytes ; mixed ; Harned coefficients ; hydrochloric acid ; mixed electrolyte solutions ; sodium chloride
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Electromotive-force measurements of the cell $$Pt;H_2 \left( {g,1{\text{ }}atm} \right)|HCl\left( {{\text{m}}_A } \right),NaCl\left( {{\text{m}}_B } \right)|AgCl;Ag$$ have been made at temperatures between 5 and 45°C at values ofm A+m B of 0.1, 0.3809, 0.6729, and 0.8720 mole-kg−1. The activity coefficients of HCl in HCl/NaCl mixtures and the Harned coefficients α12 have been obtained. The change of α12 with total molality is consistent with the existence of binary interactions between H+ and Na+ ions. The linear variation of the relative partial molal heat content with the fraction of NaCl in the mixture suggests that an analog of the Harned rule exists for this thermodynamic quantity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00645511
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  • 4
    Electronic Resource
    Electronic Resource
    Activity coefficient of hydrochloric acid in HCl/MgCl2 mixtures and HCl/NaCl/MgCl2 mixtures from 5 to 45°C (1980)
    Springer
    Journal of solution chemistry 9 (1980), S. 457-465 
    Details
    ISSN: 1572-8927
    Keywords: Activity coefficient ; electrolyte mixtures ; Harned coefficient ; hydrochloric acid ; ionic interactions ; magnesium chloride ; seawater
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Magnesium, the dominant bivalent cation in natural seawater, exerts a substantial influence on the patterns of ion interactions in this saline medium. Mean activity coefficients of hydrochloric acid in mixtures of this acid with magnesium chloride at four ionic strengths, namelyI=0.1, 0.3809, 0.6729, and 0.8720 mole-kg−1, were obtained from emf measurements of cells without liquid junction at nine temperatures from 5 to 45°C. The three highest ionic strengths correspond to seawater of salinities 20, 35, and 45‰, respectively. In addition, mixtures of HCl, NaCl, and MgCl2 were studied atI=0.6729, the molal ratio of NaCl to MgCl2 being maintained at 7.202 as in natural seawater. The Harned coefficients α1 2 were found to decrease slowly with increase in temperature. The trace activity coefficient of HCl in solutions of MgCl2 as well as in NaCl MgCl2 mixtures was found to be nearly identical with that measured earlier in synthetic seawater of the same ionic strength but containing NaCl, MgCl2, KCl, and CaCl2.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00647736
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  • 5
    Electronic Resource
    Electronic Resource
    The temperature variation of the Harned coefficient in the system HCl−NaCl (1980)
    Springer
    Journal of solution chemistry 9 (1980), S. 449-454 
    Details
    ISSN: 1572-8927
    Keywords: Activity coefficient ; electrolytes ; mixed ; Harned coefficient ; hydrochloric acid ; mixed electrolyte solutions ; sodium chloride
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The Harned coefficient measures the effect of an added electrolyte on the activity coefficient of another electrolyte. It is composite, depending partly on properties of solutions containing only one electrolyte and partly on the magnitude of a coefficient characteristic of interaction between two like charged ions in the mixed electrolyte solution. From the meager data available, the latter coefficient depends little upon temperature. The consequences of assuming temperature independence are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00647734
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  • 6
    Electronic Resource
    Electronic Resource
    The system H2O−HCl−NH4Cl at 25°C: A study of Harned's rule (1974)
    Springer
    Journal of solution chemistry 3 (1974), S. 837-845 
    Details
    ISSN: 1572-8927
    Keywords: Activity coefficient ; ammonium chloride ; Harned's rule ; hydrochloric acid ; mixtures of electrolytes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Electromotive-force measurements of cells containing hydrochloric acid and ammonium chloride at constant total molality have been used to determine the variation of the logarithm of the activity coefficient of hydrochloric acid with change in the amount of ammonium chloride in the solution. The results are interpreted in the light of the recent work of Pitzer, and it is found that Harned's rule holds for both electrolytes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00645689
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  • 7
    Electronic Resource
    Electronic Resource
    Calculation of the osmotic and activity coefficients of seawater at 25°C (1972)
    Springer
    Journal of solution chemistry 1 (1972), S. 481-488 
    Details
    ISSN: 1572-8927
    Keywords: Activity coefficient ; osmotic coefficient ; seawater
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The equation of Reilly, Wood, and Robinson was used to predict the osmotic coefficient of seawater and of its concentrates at molal ionic strengths of 0.5 to 6.0 at 25°C. The results agree closely with experimental data at ionic strengths below 5. The average difference in osmotic coefficients over the entire concentration range is 0.0014. The only serious discrepancy is at an ionic strength of 6, where a difference of 0.0068 is found. The accuracy of the predictions of osmotic coefficients prompted the calculation of the activity coefficients of NaCl, Na2SO4, MgCl2, MgSO4, KCl, and K2SO4 in the mixture. The calculated activity coefficients of NaCl and Na2SO4 agree within experimental error with previous measurements. This agreement demonstrates the prediction of activity and osmotic coefficients for complex mixtures.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00651724
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  • 8
    Electronic Resource
    Electronic Resource
    Osmotic coefficients of aqueous sodium carbonate solutions at 25°C (1979)
    Springer
    Journal of solution chemistry 8 (1979), S. 35-40 
    Details
    ISSN: 1572-8927
    Keywords: Activity coefficient ; isopiestic vapor pressure measurements ; osmotic coefficient ; sodium carbonate ; seawater ; solubilities
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Isopiestic vapor pressure measurements are reported for aqueous sodium carbonate solutions at 25°C using sodium chloride as reference electrolyte. Osmotic and activity coefficients are calculated from the concentrations of the solutions in isopiestic equilibrium. The results are used to calculate the trace activity coefficients of carbonate ion in sodium chloride solutions; these should approximate the trace activity coefficient of carbonate ion in seawater. The solubility of sodium carbonate in water at 25°C has been determined.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00646807
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  • 9
    Electronic Resource
    Electronic Resource
    Standardization of silver-silver chloride electrodes from 0 to 60°C (1980)
    Springer
    Journal of solution chemistry 9 (1980), S. 455-456 
    Details
    ISSN: 1572-8927
    Keywords: Activity coefficient ; hydrochloric acid ; silver—silver chloride electrode
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Reference values of the activity coefficient of hydrochloric acid at intervals of 5°C from 0 to 60°C are proposed. With their use, interlaboratory differences among silver—silver chloride electrodes can be eliminated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00647735
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