Notice one more feature. Comparing Fig. 4 and 5 we can see that the behavior of
Ca
2+
concentration within i = 50 ÷85 depends upon calculation method. Calculation of
curve 2 in Fig. 4 was made by the formula (10), in Fig. 6 – by (12). This fact is the
evidence of inadequacy of quasiequilibrium approximation with experimental data.
To trace the relaxation of reactions connected with CO
2
present the rate of carbon
dioxide transformation in the form where degassing components and intrasystem
transformations denoted as R
2
are clearly
shown,
2
2e
2
2
2
R
)
X
(X
a
X
+
−
=
,
(16)
Using data a
2
= 0.129 sec
-1
and X
2e
=
2.55∙10
-5
mol/dm
3
obtained
at
the
agreement of calculated by (12) and
experimental data of Ca
2+
concentration
(see Fig. 5) for the rate of reactions R
2
the
dependence shown in Fig. 7 has been
obtained. It follows from Fig. 7 that
equilibrium in CO
2
subsystem comes
during 115 run, i.e. in 29 min. after
degassing start and 7 min. after total
crystallization start approaching to its maximum at i = 100.
Equilibrium with regards to the first two reactions (7) is characterized by the
complex
2
2
1
2
7
3
qe
3
3
123
X
K
K
Y
Y
X
X
G
=
=
, Yi – appropriate ions activities,
(17)
Figure 7. Time dynamics of the rate of intra-
system reactions of CO
2
transformation in
CHCS mol/sec. Reactions are practically
equilibrium at 115 measurement.
R
2
i
Figure 5. Dependence of molar Ca
2+
concentration upon the number of
measurement i. Curve 1-experimen- tal
data, curve 2- calculation by (12).
1
2
[
Ca
2+
]
i
Figure 6. Dependence of relationship of the
experimental and calculated by (12) Ca
2+
ions concentration upon the number of
measurement i, Δi= 27 s.
і
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