INSTITUTE OF SCIENCE
Conductivity of Positive Ions. S.H. Shakman
A notable order of agreement between calculated and observed
conductivity values (within 10% for a majority of positive
inorganic ions listed by CRC*) may be derived when ions are
assigned [either anhydrous (a) or maximally hydrated (h)] weight
values (Wa,Wh) in accord with Flint's description of hydrational
potentiality**; and relative conductivities are calculated as
inverse square root of weight (in accord with Graham's law of
diffusion, as first treated by Flint***).
Table - Equivalent Conductivity, Calculated vs Observed
Ion: H+ Li+ Na+ K+ Rb+ Cs+ [H+:
W(a or h)** 4(a) 350(h) 222(h) 94(h) 76(a) 112(a) K+]
1//W .5000 .0535 .0671 .1031 .1147 .0945 4.85
Calculated [BASE ]
Conductivity 373.1 39.9 [50.08] 77.0 85.6 70.5 4.85
Observed 349.65 38.66 50.08 73.48 77.8 77.2 4.76
*CRC Handbook of Chemistry and Physics, 1985-6, D-167-8.
**FLINT, L.H., Behavior Patterns of Hydration (1964), 21:
Wa=2(atomic no.+/-valence); Wh=Wa+18H, when H=23n-(atomic
no.+/-valence), H varies from 23 to 0 and n from 1 to 4.
***FLINT, L.H., J. Washington Acad. of Sci., 22 (1932), 98.
1987 AAAS Abstract #111; (c) 1985 SHShakman Txu219626
Flint, 1964, p. 18-9: In that his initially-determined
hydration numbers were integers as per [A] above, Flint had
next postulated integers for ionic weights (twice the atomic
numbers) and then a change in weight with ionization:
"The third and final step which marked the definitive
diagnosis of hydrational potentiality was the introduction
of the postulate of a specific change in weight with
ionization. ... It was a drastic revolutionary and
seemingly incredible step, but it permitted an integration
of observational data with a satisfying convincing nicety. ...
"At the time of the discovery in 1932, I had attained the
age of 39, an age held and maintained by no less an authority
than Jack Benny to represent the very peak of perfection in
a numan male. ..."
Flint then turned his attention to attempts to validate
the description using specific gravities, etc., whereas a
measure of validation may be derived from the ability to
extend this system to a majority of positive ions, as
[M. Berkowitz and W. Wan, Journal of Chemical Physics
(1 January 1987, p. 377): "To describe the limiting ionic
mobility on a molecular level is a very challenging task ..."]
AAAS Abstract #111; (c)1985 S H
Shakman Txu219626. All rights reserved.