RES³T - Rossendorf Expert System for Surface and Sorption Thermodynamics

Show Detailed Site Query Results

Binding Site Data:

Mineral:	Akaganeite
Reference:	KM89a
SCM Type:	TL - Triple Layer
Ionic Strength:	0.0 mol/L of KNO3
Site Type:	»Fe-OH
PZC:	7.25
pK1:	4.2	pK1°_I=0 (Conversion to I = 0):	4.20	pK1_{2.31 nm⁻²} (normalized):	5.68
pK2:	10.6	pK2°_I=0 (Conversion to I = 0):	10.60	pK2_{2.31 nm⁻²} (normalized):	9.12
Site Density in nm^-2:	70.2572
Original Site Density:	0.00602 mol / g solid
Solid/Liquid Ratio in g/L:	3.0
pH Range:
Temperature in K:
Method for Site Density:	Potentiometric Titration
Method for Protolysis:	Potentiometric Titration
Fit Method:	graphic extrapolation
Comment:	SSD: adsorption of H+ or OH- from 0.1M HNO3 or 0.1M KOH after 24h equilibration [BM81]; SSD 70 sites/nm^2 (!), TGA: 14.5% H2O (corresponds to about 8.05 mmol/g surface moisture, therefore the value of SSD per unit weight is reasonably accurate, however SSD per unit surface area is high, obviously because of underestimation of SSA): nevertheless doubtful value; single extrapolation to zero-charge condition for titration in 0.001M KNO3; double extrapolation to alpha=c=0: pK1=4.0, pK2=10.5

1 data sets were retrieved