1017 
12. Other equilibria of the type ABZ A+ B. 
None of the data which are to be found in the literature on 
other equilibria of the above type, allow of a sufficiently accurate 
calculation of the moments of inertia. 
There exists a very interesting investigation on hydrogen dissocia- 
tion by Lanemurr, who coneludes to dissociation of the hydrogen 
molecules from the abnormally high energy required to keep the 
tungsten wires in a hydrogen atmosphere at high temperature, and 
who tries to calculate the degree of dissociation from these energy 
measurements. *) On account of the insufficient accuracy of the 
required quantities these calculations cannot yield any but rough 
values. From the values of the degree of dissociation, which LANGMUIR 
considers the most probable, I have calculated the moment of inertia 
by the aid of equation 4 and 4a, resp. 6 and 6a of my preceding 
communication ; the limits for the values for log M found thus amount 
to — 44.3 (Terrope and vaN pER Waats at À =0), and — 45.3 
(vAN DER Waars at A=20u). From this moment of inertia the 
value 8.10! resp. 2.5.10-" em. would follow for the atom distance. 
The moment of inertia of hydrogen, however, is in my opinion suffi- 
ciently accurately known to justify us in rejecting these values, and 
in concluding that the values given by Langmuir, are not accurate. 
Reversely it would certainly be of importance to seek an inter- 
pretation of the phenomena found by Lanemuir, by the aid of equa- 
tions 4 and 6 and of the value of the moment of inertia of hydrogen, 
as it is found according to other methods. *). 
The chlorine dissociation has been examined at temperatures 
between 1760 and 2000 K. by Pier; owing to the great experi- 
mental difficulties accompanying this investigation, these values are 
not accurate either. °) If we calculate for this case the value of the 
moment of inertia, we find values for log M varying between about 
— 54 and — 37. Now we can certainly disregard the smallest values, 
because they are found from the determinations at the lowest tem- 
peratures, where the degree of dissociation is very small, and a 
small absolute error manifests itself greatly enlarged in the equili- 
brium constant. But also at the higher temoeratures the value of 
log M varies too much to allow us to draw satisfactory conclusions. 
The case of the bromine dissociation is somewhat more favourable. 
If we apply the equations 4 and 6 to the values found by Prrman 
1) LANeMuIR, Journ. Amer. Chem. Soc. 34. 860. (1912). 
2) Cf. for the moment of inertia of hydrogen among others Einstein and Stern, 
Ann. der. Physik. (4) 40. 551. (1913). 
5) Pier, Zeitschr. f. physik, Chemie. 62. 417, (1908). 
