### Abstract

The scope of this article is to study the ability of different equations for K-2 and different sets of Pitzer parameters to model the thermodynamic properties of the H2SO4-H2O system over a wide temperature range. Three Pitzer parameters are found essential in modeling aqueous sulfuric acid, namely, C-phi for H+/SO42- interaction and parameters beta((0)) and beta((1)) for H+/HSO4- interaction. Several thermodynamic models with different K-2-equations consisting of only four Pitzer parameters, the mentioned three parameters extended by beta(0) for H+/SO42- interaction with simple temperature dependency (a + b/T), can describe stoichiometric activity and osmotic coefficients as well as vapor pressure of aqueous sulfuric acid up to a 6 molal solution in the temperature range (0 to 170) degrees C with good to moderate extrapolation capabilities. Increasing the number of parameters above four do not improve the assessment. The predicted values with different K-2-equations are assumed experimentally accurate. One of the four parameters models, Hepler A, can predict the apparent heat of solution in the temperature range (0 to 50) degrees C with reasonable accuracy even though no enthalpy or heat capacity data were included in the assessment.

Original language | English |
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Pages (from-to) | 3009-3032 |

Number of pages | 24 |

Journal | Journal of Chemical and Engineering Data |

Volume | 58 |

Issue number | 11 |

DOIs | |

Publication status | Published - Nov 2013 |

MoE publication type | A1 Journal article-refereed |

### Keywords

- ELECTROMOTIVE-FORCE MEASUREMENTS
- SOLVENT ELECTROLYTE SYSTEMS
- MODELING PHASE-EQUILIBRIA
- THERMODYNAMIC PROPERTIES
- OSMOTIC COEFFICIENTS
- IONIC-SOLUTIONS
- BISULFATE ION
- ISOPIESTIC DETERMINATION
- ELEVATED-TEMPERATURES
- MINERAL SOLUBILITIES