### Abstract

The Henry's law constants H for chloroform, 1,1-dichloroethane, 1,2-dichloropropane, trichloroethene, chlorobenzene, benzene and toluene were determined by the EPICS-SPME technique (equilibrium partitioning in closed systems - solid phase microextraction) in the temperature range 275-343 K. The curvature observed in the 1n H vs. 1/T plot was due to the temperature dependence of the change in enthalpy ΔH^{0} during the transfer of 1 mol solute from the aqueous solution to the gas phase. The nonlinearity of the plot was explained by means of a thermodynamic model which involves the temperature dependence of ΔH^{0} of the compounds and the thermal expansion of water in the three-parameter equation In (HΡ_{T}T) = A_{2}/T + BT_{B} + C_{2}, where Ρ_{T} is the density of water at temperature T, T_{B} = 1n(T/298) + (298 - T)/T, A_{2} = -ΔH_{298}^{0}/R, ΔH_{298}^{0} is the ΔH^{0} value at 298 K, B = ΔC_{P}^{0}/R, and C_{2} is a constant. AC_{p}^{0} is the molar heat capacity change in volatilization from the aqueous solution. A statistical comparison of the two models demonstrates the superiority of the three-parameter equation over the two-parameter one 1n H vs. 1/T). The new, three-parameter equation allows a more accurate description of the temperature dependence of H, and of the solubility of volatile organic compounds in water at higher temperatures.

Original language | English |
---|---|

Pages (from-to) | 757-762 |

Number of pages | 6 |

Journal | Chemosphere |

Volume | 48 |

Issue number | 7 |

DOIs | |

Publication status | Published - 2002 |

### Fingerprint

### Keywords

- Air-water partitioning
- Heat capacity of hydration
- Henry's law constant
- Hydration thermodynamics
- Solid-phase microextraction

### ASJC Scopus subject areas

- Environmental Chemistry
- Environmental Science(all)

### Cite this

*Chemosphere*,

*48*(7), 757-762. https://doi.org/10.1016/S0045-6535(02)00131-5

**Temperature dependence of Henry's law constant in an extended temperature range.** / Görgényi, M.; Dewulf, Jo; Van Langenhove, Herman.

Research output: Contribution to journal › Article

*Chemosphere*, vol. 48, no. 7, pp. 757-762. https://doi.org/10.1016/S0045-6535(02)00131-5

}

TY - JOUR

T1 - Temperature dependence of Henry's law constant in an extended temperature range

AU - Görgényi, M.

AU - Dewulf, Jo

AU - Van Langenhove, Herman

PY - 2002

Y1 - 2002

N2 - The Henry's law constants H for chloroform, 1,1-dichloroethane, 1,2-dichloropropane, trichloroethene, chlorobenzene, benzene and toluene were determined by the EPICS-SPME technique (equilibrium partitioning in closed systems - solid phase microextraction) in the temperature range 275-343 K. The curvature observed in the 1n H vs. 1/T plot was due to the temperature dependence of the change in enthalpy ΔH0 during the transfer of 1 mol solute from the aqueous solution to the gas phase. The nonlinearity of the plot was explained by means of a thermodynamic model which involves the temperature dependence of ΔH0 of the compounds and the thermal expansion of water in the three-parameter equation In (HΡTT) = A2/T + BTB + C2, where ΡT is the density of water at temperature T, TB = 1n(T/298) + (298 - T)/T, A2 = -ΔH2980/R, ΔH2980 is the ΔH0 value at 298 K, B = ΔCP0/R, and C2 is a constant. ACp0 is the molar heat capacity change in volatilization from the aqueous solution. A statistical comparison of the two models demonstrates the superiority of the three-parameter equation over the two-parameter one 1n H vs. 1/T). The new, three-parameter equation allows a more accurate description of the temperature dependence of H, and of the solubility of volatile organic compounds in water at higher temperatures.

AB - The Henry's law constants H for chloroform, 1,1-dichloroethane, 1,2-dichloropropane, trichloroethene, chlorobenzene, benzene and toluene were determined by the EPICS-SPME technique (equilibrium partitioning in closed systems - solid phase microextraction) in the temperature range 275-343 K. The curvature observed in the 1n H vs. 1/T plot was due to the temperature dependence of the change in enthalpy ΔH0 during the transfer of 1 mol solute from the aqueous solution to the gas phase. The nonlinearity of the plot was explained by means of a thermodynamic model which involves the temperature dependence of ΔH0 of the compounds and the thermal expansion of water in the three-parameter equation In (HΡTT) = A2/T + BTB + C2, where ΡT is the density of water at temperature T, TB = 1n(T/298) + (298 - T)/T, A2 = -ΔH2980/R, ΔH2980 is the ΔH0 value at 298 K, B = ΔCP0/R, and C2 is a constant. ACp0 is the molar heat capacity change in volatilization from the aqueous solution. A statistical comparison of the two models demonstrates the superiority of the three-parameter equation over the two-parameter one 1n H vs. 1/T). The new, three-parameter equation allows a more accurate description of the temperature dependence of H, and of the solubility of volatile organic compounds in water at higher temperatures.

KW - Air-water partitioning

KW - Heat capacity of hydration

KW - Henry's law constant

KW - Hydration thermodynamics

KW - Solid-phase microextraction

UR - http://www.scopus.com/inward/record.url?scp=2442586697&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=2442586697&partnerID=8YFLogxK

U2 - 10.1016/S0045-6535(02)00131-5

DO - 10.1016/S0045-6535(02)00131-5

M3 - Article

VL - 48

SP - 757

EP - 762

JO - Chemosphere

JF - Chemosphere

SN - 0045-6535

IS - 7

ER -