### Abstract

The enthalpies of dilution of lithium, sodium, potassium, and magnesium chloride and sulfate solutions in the range 0.1 to 1.0 m have been measured at 30°C with a microcalorimeter. The relative apparent enthalpies φ_{L} of these solutions have been determined with the aid of an extended form of the Debye-Hückel limiting law {Mathematical expression} where S_{H} is the limiting-law slope, σ = 3/I^{3/2} × [(1+I^{1/2} - 1/(1+I^{1/2} - 2 ln (2+I^{1/2})], and B and C are empirical constants. This equation fits the experimental results to within a standard deviation of 2 cal-mole^{-1} for all the salts. The measured φ_{L} for the MgSO_{4} solutions were compared to those calculated using the additivity principle, φ_{L}(MgCl_{2}) + φ_{L}(Na_{2}SO_{4}) - 2φ_{L}(NaCl), and the extended Debye-Hückel equation. The results of this comparison have been used to calculate the ΔH_{A}
^{o} for the formation of MgSO_{4}
^{0}. A value of ΔH_{A}
^{o} = 1.15 to 1.36 was obtained, depending upon the φ_{L} estimates for the free ions Mg^{2+} and SO_{4}
^{2-}. The results are briefly discussed and compared to the results obtained by other workers.

Original language | English (US) |
---|---|

Pages (from-to) | 145-159 |

Number of pages | 15 |

Journal | Journal of Solution Chemistry |

Volume | 4 |

Issue number | 2 |

DOIs | |

State | Published - Feb 1975 |

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### Keywords

- dilution
- Enthalpy
- ion pairs
- lithium, sodium, and potassium chlorides and sulfates

### ASJC Scopus subject areas

- Physical and Theoretical Chemistry

### Cite this

*Journal of Solution Chemistry*,

*4*(2), 145-159. https://doi.org/10.1007/BF00649155

**The enthalpy of formation of magnesium sulfate ion pairs.** / Leung, Wing H.; Millero, Frank J.

Research output: Contribution to journal › Article

*Journal of Solution Chemistry*, vol. 4, no. 2, pp. 145-159. https://doi.org/10.1007/BF00649155

}

TY - JOUR

T1 - The enthalpy of formation of magnesium sulfate ion pairs

AU - Leung, Wing H.

AU - Millero, Frank J

PY - 1975/2

Y1 - 1975/2

N2 - The enthalpies of dilution of lithium, sodium, potassium, and magnesium chloride and sulfate solutions in the range 0.1 to 1.0 m have been measured at 30°C with a microcalorimeter. The relative apparent enthalpies φL of these solutions have been determined with the aid of an extended form of the Debye-Hückel limiting law {Mathematical expression} where SH is the limiting-law slope, σ = 3/I3/2 × [(1+I1/2 - 1/(1+I1/2 - 2 ln (2+I1/2)], and B and C are empirical constants. This equation fits the experimental results to within a standard deviation of 2 cal-mole-1 for all the salts. The measured φL for the MgSO4 solutions were compared to those calculated using the additivity principle, φL(MgCl2) + φL(Na2SO4) - 2φL(NaCl), and the extended Debye-Hückel equation. The results of this comparison have been used to calculate the ΔHA o for the formation of MgSO4 0. A value of ΔHA o = 1.15 to 1.36 was obtained, depending upon the φL estimates for the free ions Mg2+ and SO4 2-. The results are briefly discussed and compared to the results obtained by other workers.

AB - The enthalpies of dilution of lithium, sodium, potassium, and magnesium chloride and sulfate solutions in the range 0.1 to 1.0 m have been measured at 30°C with a microcalorimeter. The relative apparent enthalpies φL of these solutions have been determined with the aid of an extended form of the Debye-Hückel limiting law {Mathematical expression} where SH is the limiting-law slope, σ = 3/I3/2 × [(1+I1/2 - 1/(1+I1/2 - 2 ln (2+I1/2)], and B and C are empirical constants. This equation fits the experimental results to within a standard deviation of 2 cal-mole-1 for all the salts. The measured φL for the MgSO4 solutions were compared to those calculated using the additivity principle, φL(MgCl2) + φL(Na2SO4) - 2φL(NaCl), and the extended Debye-Hückel equation. The results of this comparison have been used to calculate the ΔHA o for the formation of MgSO4 0. A value of ΔHA o = 1.15 to 1.36 was obtained, depending upon the φL estimates for the free ions Mg2+ and SO4 2-. The results are briefly discussed and compared to the results obtained by other workers.

KW - dilution

KW - Enthalpy

KW - ion pairs

KW - lithium, sodium, and potassium chlorides and sulfates

UR - http://www.scopus.com/inward/record.url?scp=0000351819&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0000351819&partnerID=8YFLogxK

U2 - 10.1007/BF00649155

DO - 10.1007/BF00649155

M3 - Article

AN - SCOPUS:0000351819

VL - 4

SP - 145

EP - 159

JO - Journal of Solution Chemistry

JF - Journal of Solution Chemistry

SN - 0095-9782

IS - 2

ER -