2085
IRON(II1) THIOCYANATE IN DIOXANE
April 20, 1955
The various reactions reported in this investigation were studied over a range of temperatures from 10 to 40'. The values of K used for calculation ranged from 0.6 X 10-6 a t 10" to 3.0 X a t 40°, as a result of determinations of the PH dependence a t these temperatures. The results were plotted according t o the theory of absolute reaction rates, and the heats of activation and entropies of activation shown in Table I11 were calculated. TABLE I11
+
*
AH kcal./mdle
Cr(HzO)e+++ Mal' Cr(Mal)(HzO)d+ Mal' Cr(Mal)z(HZO)nMal' Cr(Ox)?(HnO)z- f Ox'
+ +
iii ,n-c--r--n-
c --r/
\OH*
fast __f __f
slow
I H
O
H
0
I I1 0-C-C-C-0II
3.3
THE
II 1I ,o-c-c-00-c-c-0\
4-c-c-0-+ I I1
0-
cr
