Mineral: |
Goethite |
Reference: |
S79 |
SCM Type: |
CC - Constant Capacitance |
Ligand: |
PO4<3->
- phosphate
|
Site Type: |
»Fe-OH |
Equation: |
2 »Fe-OH + PO4<3-> + 2 H<1+> ⇔ (»Fe)2-PO4<1-> + 2 H2O |
LogK: |
26.202 LogK°I=0 (Conversion to I = 0): 27.38
LogK2.31 nm−2 (SSD-normalized): 36.74
|
Experiment: |
Potentiometric Titration |
Ionic Strength: |
0.1 mol/L
NaClO4
|
Temperature: |
295.15 K |
Solid/Liquid Ratio: |
6.0 g/L |
pH Range: |
3.5-10 |
Ligand Concentration Range: |
2E-4. 5E-4. 8E-4. 1E-3 mol/L |
Fit Method: |
graphic extrapolation |
Comment: |
cited in [SKS80], [SS87] and [SS80], SCM named \"ligand exchange model\", dependece on charge e^(F psi/R T); original reaction equation in the study: 2 »Fe-OH + H3PO4 = (»Fe)2-PO4<1-> + H<1+> + 2 H2O with logK = 4.5, formation constant in aqueous solution: PO4<3-> + 3H<1+> = H3PO4 logK = 21.702 [GFFGN03] |
|