Vol. 4 , No. 3, March 1965
CHELATING
+ HzO +Cr(HzO)$+ kHpO
Cr(Hz0)b3+
This mechanism accounts for the observed retardation : if the steady-state condition d[Cr(H20)63+]/dt= 0 is assumed, i t follows that d[Cr12+] = kH,o [Cr(Hz0)b3+1= dt kH,oko
k1[1-] f kH,o
[Cr12+]= k [Cr12+]
Hence, the rate constant k is decreased by iodide. This effect will be negligible only if k I [ I ]
