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Table 3 Equilibrium constants for acetate and malonate complexes of Pb and Zn used in model calculations

From: Transport of Pb and Zn by carboxylate complexes in basinal ore fluids and related petroleum-field brines at 100 °C: the influence of pH and oxygen fugacity

Acetate (Ac- = CH3COO-) Malonate (Ma2- = C3H2O42-)
Reaction LogK T/°C Ref.a Reaction LogK T/°C Ref.a
H+ + Ac- → Hac 4.94 100 1 H+ + HMa- → H2Ma 3.02 100 5
     H+ + Ma2- → HMa- 6.14 100 5
Pb2+ + Ac- → PbAc+ 3.00 100 2     
Pb2+ + 2Ac- → Pb(Ac)2 4.69 100 2 Pb2+ + Ma2+ → PbMa 2.79 25 6
Pb2+ + 3Ac- → Pb(Ac)3 3.66 100 3 Pb2+ + 2Ma2+ → Pb(Ma)22- 5.70 25 6
     Pb2+ + HMa- → PbHMa+ 2.40 25 6
Zn2+ + Ac- → ZnAc+ 2.30 100 4 Pb2+ + 2HMa- → Pb(HMa)2 2.40 25 6
Zn2+ + 2Ac- → Zn(Ac)2 4.00 100 4     
Zn2+ + 3Ac- → Zn(Ac)3 4.70 100 4 Zn2+ + Ma2- → ZnMa 3.84 25 7
     Zn2+ + 2Ma2- → Zn(Ma)22- 5.40 25 7
     Zn2+ + HMa+ → ZnHMa+ 1.00 25 7
  1. a(1) Mesmer et al.[84] (2) Extrapolation based on 24 to 85°C data from Giordano[85] and Hennet et al.[50] (3) SOLMINEQ.88, Kharaka et al.[86] (4) Giordano and Drummond. (5) Kettler et al.[88] (6) Data from Hammam et al.[89] extrapolated to I = 0. (7) Evans and Monk.[90]