[F] OPTIONS:3+3 [Hydration * Specific Gravity]. S.H. ShakmanA. Agreement (w/in 10%) between observed and calculated
conductivity values for majority of (49) positive ions calc. as per
1987 AAAS Abstract #111 (see [B]) may be extended to major-
ity of total 108 ions in CRC 1985, D167, when 3rd hydrational
assumption is allowed (max-per-Flint)/2. Ions in each of 3
below groups often relate sequentially &/or thru Mendeleev.:
(1)Hydration # [H]=zero for all 12 listed positive
lanthanide ions; H+,OH-; Cs+,Rb+; SO3-2,SO4-2,S2O4-2;
(2)H=maximum-per-Flint for Li+[H=19],Na+,K+; Be++
(3)(H=max-per-Flint)/2 for Mn++[H=19/2],Fe++[18/2],Co++
Abegg & Bodlander in 1899[Z.Anorg. Chem.20,491] thought
resp. conductivities evidenced anhydrous H+ & OH- ions;
Flint indicated such for H+,Rb+,Cs+ w/Cl- [1932,p.233].
Bousfield in 1906[Phil.Trans.206A,124] posited H=3.5 for Cl-.
Error Pos (49) Neg (59) Total (108)
max l/2 0 T max 1/2 0 T max 1/2 0 T
w/in 10% 8 6 18 32 8 8 9 25 16 14 27 57
w/in 20% 8 8 19 35 17 11 11 39 25 19 30 74
B. Flint in 1964 [Behavior Patterns...,Chs.3,15] derived
hydrated volume (Vh) as a function of anhydrous (Wa) and hydra-
ted (Wh) wts. [Vh=Wh/(1+Wa/Wh)]; subtracted Vh in cc from 1000
to derive volume of free water in a 1-liter solution; added
added same free-water amount in grams to wt. of hydrated sol-
ute; and divided result by 1000 to calculate specific gravity.
Curiously Flint used 2 distinct methods to determine ratio
(Wa/Wh) in above equation for Vh:
(1) ratio for total molecule [used in [G] 1987 AAAS Abstract#113; &
(2) average of individual ionic ratios.
As a 3rd option, individual ionic hydrated volumes might be summed.
[W.G. Ganong, Rev. of Med. Physiology (1975), p. 12]: "The ions
in the body are hydrated, and although the atomic weight of
potassium (39) is greater than that of sodium (23) the hydrated
sodium ion, i.e., Na+ with its full complement of water, is
larger than the hydrated potassium ion."
Encyclopedia Britannica (198?): "... the ions Cl-, Br-, and I- have
almost identical mobilities although it might be expected that the
heavy and bulky I- ion would a much lowermobility than the lighter
and smaller Cl- ion. Even more surprisinigly, the small and light
lithium (Li+) ion has only about half the mobility of the heavy
cesium (cs+) ion."
Copyright 1988 S H Shakman. All rights reserved. [HOME]