Apparent molar volumes and apparent molar heat capacities of aqueous KI, HIO3, NaIO3, and KIO3 at temperatures from 278.15 K to 393.15 K and at the pressure 0.35 MPa

https://doi.org/10.1016/j.jct.2007.05.008Get rights and content

Abstract

We determined apparent molar volumes Vϕ at 298.15  (T/K)  368.15 and apparent molar heat capacities Cp,ϕ at 298.15  (T/K)  393.15 for aqueous solutions of HIO3 at molalities m from (0.015 to 1.0) mol · kg−1, and of aqueous KIO3 at molalities m from (0.01 to 0.2) mol · kg−1 at p = 0.35 MPa. We also determined Vϕ at the same p and at 298.15  (T/K)  368.15 for aqueous solutions of KI at m from (0.015 to 7.5) mol · kg−1. We determined Cp,ϕ at the same p and at 298.15  (T/K)  393.15 for aqueous solutions of KI at m from (0.015 to 5.5) mol · kg−1, and for aqueous solutions of NaIO3 at m from (0.02 to 0.15) mol · kg−1. Values of Vϕ were determined from densities measured with a vibrating-tube densimeter, and values of Cp,ϕ were determined with a twin fixed-cell, differential temperature-scanning calorimeter. Empirical functions of m and T were fitted to our results for each compound. Values of Ka, ΔrHm, and ΔrCp,m for the proton ionization reaction of aqueous HIO3 are calculated and discussed.

Introduction

Potassium salts of many ions are strong electrolytes in aqueous solutions and find many uses in modern chemistry. The salt KIO3 is one of the most versatile analytical reagents, and the thermodynamic properties of KI have been studied in great detail. In this paper, we compare our calculated values of Vϕ and Cp,ϕ to those reported in the literature for aqueous KI and KIO3. Aqueous solutions of HIO3 have not been studied as extensively, and we also report our values for this system and compare them to the literature values.

In this investigation we report values of Vϕ and Cp,ϕ or aqueous KI, HIO3, and KIO3, as well as values of Cp,ϕ for aqueous NaIO3, and their dependencies on temperature T and molality m. We used results from a vibrating tube densimeter to obtain our values of Vϕ and we used results from a twin fixed-cell temperature scanning calorimeter to obtain our values of Cp,ϕ. We report values of Vϕ for aqueous KI at 0.015  (m/mol · kg−1)  7.5, for aqueous HIO3 at 0.015  (m/mol · kg−1)  1.0, and for aqueous KIO3 at 0.01  (m/mol · kg−1)  0.2, all at 278.15  (T/K)  368.15 and at p = 0.35 MPa. We report experimental values of Cp,ϕ for KI at 0.015  (m/mol · kg−1)  5.5, for HIO3 at 0.015  (m/mol · kg−1)  1.0, for NaIO3 at 0.02  (m/mol · kg−1)  0.15, and for KIO3 at 0.01  (m/mol · kg−1)  0.2, all at 278.15  (T/K)  393.15. Values of Cp,ϕ for aqueous NaIO3 and KIO3 are compared and those for aqueous HIO3 and KIO3 are combined with previously reported Cp,ϕ data for aqueous HCl and KCl [1] to calculate values of Ka, ΔrHm, and ΔrCp,m for the deprotonation reaction of aqueous HIO3.

Section snippets

Experimental

We used potassium iodide (KI, molar mass M2 = 166.0028 g · mol−1, Columbus Chemical Industries, Inc., product no. 4370LB, lot 200120707, reported purity ⩾0.999 mass fraction), iodic acid (HIO3, M2 = 175.9107 g · mol−1, Sigma–Aldrich product no. 221929, lot 05907MC, reported purity = 1.015 mass fraction by thiosulfate titration), sodium iodate (NaIO3, M2 = 197.8923 g · mol−1, Fisher Scientific product no. S322-100, lot 955668, reported purity ⩾0.999 mass fraction), and potassium iodate (KIO3, M2 = 214.0012 g · mol−1,

Results and discussion

Values of Vϕ for aqueous KI, HIO3, and KIO3 were calculated using the following equation:Vϕ=(M2/ρs)-(ρs-ρw)/(ρs·ρw·m),where ρw is the density of water [5]. Our experimental values of ρs(m, T), as well as the calculated values of Vϕ(m, T) and their uncertainties are given in TABLE 1, TABLE 2, TABLE 3 for aqueous KI, HIO3, and KIO3, respectively. The estimated uncertainties in TABLE 1, TABLE 2, TABLE 3 were obtained by using standard error propagation methods as described previously [3].

The

References (28)

  • B.A. Patterson et al.

    J. Chem. Thermodyn.

    (2001)
  • K. Ballerat-Busserolles et al.

    J. Chem. Thermodyn.

    (1999)
  • T.L. Niederhauser et al.

    J. Chem. Thermodyn.

    (2004)
  • E.C. Sorenson et al.

    J. Chem. Thermodyn.

    (2003)
  • P.P.S. Saluja et al.

    J. Chem. Thermodyn.

    (1992)
  • J.J. Spitzer et al.

    Thermochim. Acta

    (1979)
  • O. Enea et al.

    J. Chem. Thermodyn.

    (1977)
  • P.P.S. Saluja et al.

    Can. J. Chem.

    (1986)
  • International Critical Tables, vol. 3, McGraw-Hill, New York, 1928, p. 55, 87,...
  • E. Garcia-Paneda et al.

    J. Chem. Soc.

    (1994)
  • G.T. Hefter et al.

    J. Solution Chem.

    (1989)
  • G.T. Hefter et al.

    J. Soution Chem.

    (1990)
  • A.F. Vorob’ev et al.

    Zh. Fiz. Khim.

    (1982)
  • L.A. Dunn

    Trans. Faraday Soc.

    (1968)
  • Cited by (19)

    • Volumetric properties of aqueous solution of lithium tetraborate from 283.15 to 363.15 K at 101.325 kPa

      2018, Journal of Chemical Thermodynamics
      Citation Excerpt :

      The volumetric property of aqueous electrolyte solutions plays a very important role in elucidating the structural interactions occurring in solution. In order to further researching on the structural interactions occurring in solution, some aqueous systems containing chloride, iodide, nitrate, sulfate have been researched, such as LiCl + H2O [6], NaCl + H2O [7], KCl + H2O, RbCl + H2O, CsCl + H2O [8], MgCl2 + H2O, CdCl2 + H2O [9], CaCl2 + H2O [10], SrCl2 + H2O [11], AlCl3 + H2O, NaCl + KCl + H2O [12], CaCl2 + NaCl + H2O, MgCl2 + NaCl + H2O [13], KCl + CaCl2 + H2O [14], KCl + NaCl + H2O [15], KI + H2O, HIO3 + H2O, NaIO3 + H2O, KIO3 + H2O [16], Mg(NO3)2 + H2O, Sr(NO3)2 + H2O, Mn(NO3)2 + H2O [17], RbNO3 + H2O, CsNO3 + H2O, Sr(NO3)2 + H2O, Y(NO3)3 + H2O, Ga(NO3)3 + H2O [18], Li2SO4 + H2O [19], K2SO4 + H2O [20], Na2SO4 + H2O, +Na2SO4 + NaCl + H2O [21], VOSO4 + H2O [22]. The temperature, concentration, and pressure dependences of the density, apparent and partial molar volumes were reported.

    • Effect of temperature on compressibility properties of 0.1, 0.5 and 1.0 molal solutions of alkali metal halides. Part 1. Aqueous solutions of sodium chloride, sodium bromide, sodium iodide, potassium chloride, potassium bromide, potassium iodide, rubidium chloride and rubidium iodide in the 278.15 K to 353.15 K temperature range

      2017, Journal of Molecular Liquids
      Citation Excerpt :

      They were also expressed as polynomials of temperature, to perform interpolations for desired concentrations. A very accurate specific heat capacities (from 278.15 K to 393.15 K and at 0.35 MPa) coming from the Woolley group [82,86,89–93,95] and viscosities determined by Isono [104,107] (from 288.15 K to 328.15 K) were preferred in calculations. Introducing values of δT = ± 0.05 K, T = 298.15 K, δCP(T;m) = ± 0.01 J·g− 1, CP(T;m) = 4.138 J·g− 1, δα(T;m) = ± 2·10− 6 K− 1 and α(T;m) = 2.67·10− 4 K− 1 into Eq. (17) we have that δΔκ (T;m) = ± 9.0·10− 14 Pa− 1 which gives the error of about 2.0%.

    • A Pitzer-based characterization of aqueous magnesium chloride, calcium chloride and potassium iodide solution densities to high temperature and pressure

      2013, Fluid Phase Equilibria
      Citation Excerpt :

      Almost 90% of the residuals are between ±0.5 cm3 mol−1. Swenson and Woolley's [33] potassium iodide data at low concentration (m < 0.2) contain large standard errors and exhibit large systematic deviations from their model. Therefore, they were excluded from the present model-fitting.

    View all citing articles on Scopus
    View full text