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     The Weight of Hydrogen Gas (H2).  S.H. Shakman

A study involving approximately 200 interdiffusing gas-pairs
supports a value of 4 for the weight of H2 gas in preference to a
value of 2, on a scale of 32 for O2 gas.  Table A lists ten
illustrative gas-pairs (A-B); observed diffusion coef-
ficients (Do)*; calculations (Dc) based on viscosity data 
and conventionally-appraised molecular weight values*; cal-
culations (Dc') based on atomic numbers per equation Dc'= 
8.9585sqrt(WAsqrtWB+WBsqrtWA)/WAWB, when gases (A,B) are assigned
weight values (WA,WB) equal to double the sums of atomic
numbers of component atoms, and 8.9585 adjusts raw calcula-
tions relative to the base of .181 for N2-O2; and alternate
calculations (Dc") identically derived as are Dc' except 
that H2 is arbitrarily assigned   TABLE A-OBSERVED vs CALCUL-
a WA value of 2 (thus WA and WB   ATED DIFFUSION COEFFICIENTS 
values approximate convention-     A-B   Do   Dc   Dc'  Dc"  
ally-appraised weight values).    H2-N2  .674 .656 .703 1.133 
Note that orders of agreement     N2-O2  .181 .175 .181-BASE  
with observed values exhibited    N2-CO2 .144 .130 .149 
by Dc' values (based on a value   H2-CO  .651 .661 .703 1.133 
of 4 for the weight of H2 rela-   CO-N2  .192 .174 .197 
tive to 32 for (2) are (a) com-   CO-O2  .185 .175 .181 
parable to those exhibited by     H2-O2  .697 .689 .651 1.053 
the less-directly derived Dc      O2-CO2 .139 .128 .137 
values and (b) preferable to      H2-CO2 .550 .544 .545  .885 
those exhibited by Dc" values.    CO2-CO .137 .128 .149 

*HIRSCHFELDER, J.O., CURTISS, C.F., and BIRD, R.B., Molecu-
lar Theory of Gases and Liquids (1954), p. 579.

(As Newton affirmed,"More is in vain when less will serve.")

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