TY - JOUR

T1 - Stability constants for the formation of lead chloride complexes as a function of temperature and ionic strength

AU - Luo, Yanxin

AU - Millero, Frank J.

N1 - Funding Information:
We acknowledge the support of the Oceanographic Section of the National Science Foundation and the National Institute of Environmental Health. We thank two anonymous reviewers and Dr. Robert Byrne for their constructive suggestions.

PY - 2007/1/15

Y1 - 2007/1/15

N2 - The stability constants for the formation of lead (Pb2+) with chloridePb2 + + n Cl- ↔ PbCln2 - n βn (n = 1, 2, 3)have been determined using a spectrophotometric method in NaClO4 solutions as a function of ionic strength (0-6 m) and temperature (15-45 °C). The results have been fitted to the equations:{Mathematical expression}with standard errors of 0.05, 0.04 and 0.06, respectively. The thermodynamic values of log β1, log β2 and log β3 at 25.0 °C and the enthalpies of formation of PbCl+, PbCl20 and PbCl3- are in good agreement with literature values. We have combined our results with the earlier work of [Seward, T.M., 1984. The formation of lead (II) chloride complexes to 300 °C: a spectrophotometric study. Geochim. Cosmochim. Acta 48, 121-134.] Seward (1984) to yield thermodynamic constants that are valid from 15 to 300 °C:(log β1 =, 44.82 + 0.031 T - 21.21 log T; log β2 =, 61.42 + 0.046 T - 29.51 log T; log β3 =, 107.97 + 0.071 T - 51.46 log T)with standard errors of 0.05, 0.08 and 0.10, respectively.

AB - The stability constants for the formation of lead (Pb2+) with chloridePb2 + + n Cl- ↔ PbCln2 - n βn (n = 1, 2, 3)have been determined using a spectrophotometric method in NaClO4 solutions as a function of ionic strength (0-6 m) and temperature (15-45 °C). The results have been fitted to the equations:{Mathematical expression}with standard errors of 0.05, 0.04 and 0.06, respectively. The thermodynamic values of log β1, log β2 and log β3 at 25.0 °C and the enthalpies of formation of PbCl+, PbCl20 and PbCl3- are in good agreement with literature values. We have combined our results with the earlier work of [Seward, T.M., 1984. The formation of lead (II) chloride complexes to 300 °C: a spectrophotometric study. Geochim. Cosmochim. Acta 48, 121-134.] Seward (1984) to yield thermodynamic constants that are valid from 15 to 300 °C:(log β1 =, 44.82 + 0.031 T - 21.21 log T; log β2 =, 61.42 + 0.046 T - 29.51 log T; log β3 =, 107.97 + 0.071 T - 51.46 log T)with standard errors of 0.05, 0.08 and 0.10, respectively.

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U2 - 10.1016/j.gca.2006.09.019

DO - 10.1016/j.gca.2006.09.019

M3 - Article

AN - SCOPUS:33845671296

VL - 71

SP - 326

EP - 334

JO - Geochmica et Cosmochimica Acta

JF - Geochmica et Cosmochimica Acta

SN - 0016-7037

IS - 2

ER -