Chemistry Reference
In-Depth Information
Fig. 6.5
The absorbance variation of dextran solution oxidized by Ce
4+
with time. Backbone
polymer dextran:
open circle
s D1,
M
w
9,000;
half
-
filled circles
D2,
M
w
61,000;
filled circles
D3,
M
w
196,000
under the polymerization conditions. Absorbance was measured at 25
Cina
0.5
1 cm spectrophotometer cell. Reaction solutions were purged with nitrogen
before mixing. The wavelength at which absorbance was followed, 380 nm, was
chosen to give a reasonably large initial absorbance.
6.2.2.1 Rate of Consumption of Ce
4+
by Dextran
Figure
6.5
shows the absorbance variation of dextran solution oxidized by Ce
4+
with time. The overall kinetic constant (
k
0
) of consumption of Ce
4+
by dextran was
calculated from the initial slopes of the logarithm of absorbance versus time [
29
]as
good pseudo-first order kinetics [cf. Eq. (
6.19
)] were observed during the initial
