1026 
the value of log K is calculated from 22, we get the values of the 
sixth column of table XI, which appreciably differ from those of 
the fifth column. This deviation can, however, be accounted for by 
this that the terms with » of HJ, and possibly also those of H, 
play a part at these high temperatures; the term with HZ will 
render the value of log K according to 22 smaller. The iodine 
vibration which prevails at low temperatures, will also continue to 
do so at high temperatures. The value of the iodine term amounts 
to — 0.277 at 7 = 1295; and ‘to. — 0.319 at 774490 - \the. term, 
therefore, which occurs in expression 22 through the vibration of 
the atoms in H/, remains below this value; and in this way an 
agreement may be probably arrived at, as the discrepancies between 
the values of the fifth and the sixth columns are smaller than the 
mentioned ones. Moreover some variation is still possible in the 
choice of the parameters of the straight line (equation 21). 
The equation 22, which is accordingly in satisfactory agreement 
with all the determinations of the iodine hydrogen equilibrium, 
MM, 
TER 
radii, as they are given by Sackur, the value of the expression 
mentioned is calculated, we find 1,21 which is therefore in good 
agreement with the preceding one. 
From formula 22 the value 2530 cal. follows for Zn lr—300, 
this value differs but little from that used by Nernst in his calcula- 
tions?); most of the data which can be derived from direct caloric 
determinations, are useless. 
yields the value 1,184 for log lf from the mean molecule 
17. From the ealeulations of the dissociation equilibria of the 
three halogen hydrogens we come therefore to the conclusion that 
the quotient of the moments of inertia agrees with that calculated 
from the mean molecule radit. 
This conclusion, at which Sackur by the aid of his expressions 
had arrived already before, but which was only meant to be roughly 
valid, appears also to be in good harmony with Prof. vaN DER 
Waars Jr.’s expression, in which the vibrations of the atoms are 
taken into account. 
Amsterdam, Dec. 1914. Anorg. Chem. Lab. of the University. 
1) Zeitschr. f, Elektrochem. 15, 687 (1909). 
