### Abstract

The thermodynamic stability constants for the hydrolysis and formation of mercury (Hg^{2+}) chloride complexes Hg^{2+} + nH_{2}O = Hg(OH)_{n}
^{(2-n)+} + nH^{+} β_{n} Hg^{2+} + nCl^{-} = HgCl_{n}
^{(2-n)+} β_{i} have been used to calculate the activity coefficients for Hg(OH)_{n}
^{(2-n)+} and HgCl_{n}
^{(2-n)+} complexes using the Pitzer specific interaction model. These values have been used to determine the Pitzer parameters for the hydroxide and chloro complexes β_{ML}
^{(0)}, β_{ML} ^{(1)} and C_{ML}). The values of λ_{ij} and ζ_{ijk} have been determined for the neutral complexes (Hg(OH)_{2} and HgCl_{2}). The resultant parameters yield calculated values for the measured values of log β* to ±0.01 from I = 0.1 to 3 m at 25°C. Since the activity coefficients of Hg(OH)_{n}
^{(2-n)+} and HgCl_{n}
^{(2-n)+} are in reasonable agreement with the values for Pb(II), we have estimated the effect of temperature on the chloride constants for Hg(II) from 0 to 300°C and I = 0-6 m using the Pitzer parameters for PbCl_{n}
^{(2-n)+} complexes. The resulting parameters can be used to examine the speciation of Hg(II) with Cl^{-} in natural waters over a wide range of conditions.

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

Pages (from-to) | 339-355 |

Number of pages | 17 |

Journal | Aquatic Geochemistry |

Volume | 13 |

Issue number | 4 |

DOIs | |

State | Published - Dec 2007 |

### Fingerprint

### Keywords

- Activity coefficients
- Chloride complexes
- Mercury(II) hydroxide
- NaClO
- Pitzer equations
- Speciation

### ASJC Scopus subject areas

- Geochemistry and Petrology
- Geophysics

### Cite this

_{4}media.

*Aquatic Geochemistry*,

*13*(4), 339-355. https://doi.org/10.1007/s10498-007-9023-y

**Use of Pitzer equations to examine the formation of mercury(II) hydroxide and chloride complexes in NaClO _{4} media.** / González-Dávila, Melchor; Santana-Casiano, J. Magdalena; Millero, Frank J.

Research output: Contribution to journal › Article

_{4}media',

*Aquatic Geochemistry*, vol. 13, no. 4, pp. 339-355. https://doi.org/10.1007/s10498-007-9023-y

_{4}media. Aquatic Geochemistry. 2007 Dec;13(4):339-355. https://doi.org/10.1007/s10498-007-9023-y

}

TY - JOUR

T1 - Use of Pitzer equations to examine the formation of mercury(II) hydroxide and chloride complexes in NaClO4 media

AU - González-Dávila, Melchor

AU - Santana-Casiano, J. Magdalena

AU - Millero, Frank J

PY - 2007/12

Y1 - 2007/12

N2 - The thermodynamic stability constants for the hydrolysis and formation of mercury (Hg2+) chloride complexes Hg2+ + nH2O = Hg(OH)n (2-n)+ + nH+ βn Hg2+ + nCl- = HgCln (2-n)+ βi have been used to calculate the activity coefficients for Hg(OH)n (2-n)+ and HgCln (2-n)+ complexes using the Pitzer specific interaction model. These values have been used to determine the Pitzer parameters for the hydroxide and chloro complexes βML (0), βML (1) and CML). The values of λij and ζijk have been determined for the neutral complexes (Hg(OH)2 and HgCl2). The resultant parameters yield calculated values for the measured values of log β* to ±0.01 from I = 0.1 to 3 m at 25°C. Since the activity coefficients of Hg(OH)n (2-n)+ and HgCln (2-n)+ are in reasonable agreement with the values for Pb(II), we have estimated the effect of temperature on the chloride constants for Hg(II) from 0 to 300°C and I = 0-6 m using the Pitzer parameters for PbCln (2-n)+ complexes. The resulting parameters can be used to examine the speciation of Hg(II) with Cl- in natural waters over a wide range of conditions.

AB - The thermodynamic stability constants for the hydrolysis and formation of mercury (Hg2+) chloride complexes Hg2+ + nH2O = Hg(OH)n (2-n)+ + nH+ βn Hg2+ + nCl- = HgCln (2-n)+ βi have been used to calculate the activity coefficients for Hg(OH)n (2-n)+ and HgCln (2-n)+ complexes using the Pitzer specific interaction model. These values have been used to determine the Pitzer parameters for the hydroxide and chloro complexes βML (0), βML (1) and CML). The values of λij and ζijk have been determined for the neutral complexes (Hg(OH)2 and HgCl2). The resultant parameters yield calculated values for the measured values of log β* to ±0.01 from I = 0.1 to 3 m at 25°C. Since the activity coefficients of Hg(OH)n (2-n)+ and HgCln (2-n)+ are in reasonable agreement with the values for Pb(II), we have estimated the effect of temperature on the chloride constants for Hg(II) from 0 to 300°C and I = 0-6 m using the Pitzer parameters for PbCln (2-n)+ complexes. The resulting parameters can be used to examine the speciation of Hg(II) with Cl- in natural waters over a wide range of conditions.

KW - Activity coefficients

KW - Chloride complexes

KW - Mercury(II) hydroxide

KW - NaClO

KW - Pitzer equations

KW - Speciation

UR - http://www.scopus.com/inward/record.url?scp=36749089016&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=36749089016&partnerID=8YFLogxK

U2 - 10.1007/s10498-007-9023-y

DO - 10.1007/s10498-007-9023-y

M3 - Article

AN - SCOPUS:36749089016

VL - 13

SP - 339

EP - 355

JO - Aquatic Geochemistry

JF - Aquatic Geochemistry

SN - 1380-6165

IS - 4

ER -