Table of Diffusion Coefficients

The tables comprise the diffusion coefficients used in aqion to calculate the electrical conductivity.1 The columns are:

z charge of ion
Di diffusion coefficient of ion i from references [P] and [V]
\(\Lambda_{m,i}^{0}\) molar limiting conductivity of ion i – calculated by Eq. (1)
\(\Lambda_{eq,i}^{0}\) equivalent limiting conductivity of ion i \(\Lambda_{eq,i}^{0} = \Lambda_{m,i}^{0}/\mid\! z_i\!\mid\)

The diffusion coefficients are selected as follows: Priority is given to the database phreeqc.dat [P], then available data from [V] are added.

Inorganic Cations

Cation |z| Di /10-9 [m2/s] \(\Lambda_{m,i}^0\) [S cm2/mol] \(\Lambda_{eq,i}^0\) [S cm2/mol] Ref
Ag+ 1 1.648 61.9 61.9 [V]
Al+3 3 0.559 188.9 63.0 [P]
Ba+2 2 0.848 127.4 63.7 [P]
Be+2 2 0.599 90.0 45.0 [V]
Ca+2 2 0.793 119.1 59.6 [P]
CaHCO3+ 1 0.506 19.0 19.0 [P]
Cd+2 2 0.717 107.7 53.8 [P]
Co+2 2 0.732 110.0 55.0 [V]
Cr+3 3 0.595 201.1 67.0 [V]
Cu+2 2 0.733 110.1 55.0 [P]
Fe+2 2 0.719 108.0 54.0 [P]
Fe+3 3 0.604 204.1 68.0 [V]
H+ 1 9.310 349.6 349.6 [P]
Hg+2 2 0.913 137.2 68.6 [V]
K+ 1 1.960 73.6 73.6 [P]
Li+ 1 1.030 38.7 38.7 [P]
Mg+2 2 0.705 105.1 53.0 [P]
MgHCO3+ 1 0.478 18.0 18.0 [P]
Mn+2 2 0.688 103.4 51.7 [P]
Na+ 1 1.330 50.0 50.0 [P]
NH4+ 1 1.980 74.4 74.4 [P]
Pb+2 2 0.945 142.0 71.0 [P]
Sr+2 2 0.794 119.3 59.6 [P]
UO2+2 2 0.426 64.0 32.0 [V]
Zn+2 2 0.715 107.4 53.7 [P]

Inorganic Anions

Anion |z| Di /10-9 [m2/s] \(\Lambda_{m,i}^0\) [S cm2/mol] \(\Lambda_{eq,i}^0\) [S cm2/mol] Ref
Br- 1 2.010 75.5 75.5 [P]
Cl- 1 2.030 76.2 76.2 [P]
CO3-2 2 0.955 143.5 71.7 [P]
CN- 1 2.077 78.0 78.0 [V]
CNO- 1 1.720 64.6 64.6 [V]
CrO4-2 2 1.132 170.0 85.0 [V]
F- 1 1.460 54.8 54.8 [P]
H2AsO4- 1 0.905 34.0 34.0 [V]
H2PO4- 1 0.846 31.8 31.8 [P]
HCO3- 1 1.180 44.3 44.3 [P]
HPO4-2 2 0.690 103.6 51.8 [P]
HS- 1 1.730 65.0 65.0 [P]
HSO4- 1 1.330 50.0 50.0 [P]
I- 1 2.045 76.8 76.8 [P]
KSO4- 1 0.746 28.0 28.0 [P]
MnO4- 1 1.632 61.3 61.3 [V]
MoO4-2 2 1.984 298.0 149.0 [V]
NaCO3- 1 0.585 22.0 22.0 [P]
NaSO4- 1 0.618 23.2 23.2 [P]
NO2- 1 1.910 71.7 71.7 [P]
NO3- 1 1.900 71.4 71.4 [P]
OH- 1 5.270 197.9 197.9 [P]
PO4-3 3 0.612 206.8 68.9 [P]
S-2 2 0.731 109.8 54.9 [P]
SeO4-2 2 1.008 151.4 76.7 [V]
SO4-2 2 1.070 160.7 80.4 [P]

Organic Anions (from Ref. [V])

Org. Anion |z| Di /10-9 [m2/s] \(\Lambda_{m,i}^0\) [S cm2/mol] \(\Lambda_{eq,i}^0\) [S cm2/mol]
Acetate- 1 1.089 40.9 40.9
Benzoate- 1 0.863 32.4 32.4
Butyrate- 1 0.868 32.6 32.6
Citrate-3 3 0.623 210.6 70.2
Dihydrogencitrate- 1 0.799 30.0 30.0
Formate- 1 1.454 54.6 54.6
Hydrogenoxalate- 1 1.070 40.2 40.2
Isovalerate- 1 0.871 32.7 32.7
Lactate- 1 1.033 38.8 38.8
Malate-2 2 0.783 117.6 58.8
Maleate-2 2 0.824 123.8 61.9
Oxalate-2 2 0.987 148.3 74.1
Phenylacetate- 1 0.815 30.6 30.6
o-Phtalate-2 2 0.696 104.6 52.3
m-Phtalate-2 2 0.728 109.4 54.7
Pivalate- 1 0.849 31.9 31.9
Salicylate- 1 0.959 36.0 36.0
Suberate-2 2 0.479 72.0 36.0
Succinate-2 2 0.783 117.6 58.8
Tartarate-2 2 0.794 119.3 59.6

References

[P]   PhreeqC (Version 3) – A Computer Program for Speciation, Batch-Reaction, One-Dimensional Transport, and Inverse Geochemical Calculations; [The diffusion coefficients are taken from the thermodynamic database “phreeqc.dat”.]

[V]   Petr Vanýsek: Ionic conductivity and diffusion at infinite dilution, Handbook of Chemistry and Physics, CRC Press, 1992/93 edition. Boca Raton, 1992. pp. (5-111)-(5-113).

Footnotes

  1. Calculations of EC are based on Eq. (10). ↩

[last modified: 2020-12-05]