Page 34 - 75_01

DÍEZ MONTORO, R. & COL. AN. R. ACAD. NAC. FARM.

For reactions between spherical molecules, nonionic and of simi-
lar sizes, (31) one is fulfilled:

k = 8RT/3?

Eq. 7 is obtained from Eq. 2 by substitution:

ze1 + ze2 = a/(1+b·?)
z01-ze1 = c
z01k’1+q(k’-1-k’1) = d/?
z02-ze2 = e
z02k’2+q(k’-2-k’2) = f/?

The rate and equilibrium constants are inversely proportional to
the viscosity of the medium, as it corresponds to molecules with spher-
ical symmetry, nonionic and of similar sizes. For constant values of
m, q and T, the activity in the equilibrium diminishes when it increas-
es viscosity.

5.5. Influence of T (Experiments 4, 14, 15, 16)

The results of experiments 4, 14, 15, 16 are fitted to the equation:

z = a·exp(b/T)+c·exp(d/T)·exp(-t·e·exp(-f/T))+g·exp(h/T)·exp(-t·j·exp(-

k/T)) Eq. 8

Its parameters, coefficient of correlation and sum of squares of
residuals are:

a = -0.445·10-12, b = 11355, c = 1.893·109, d = -3913, e = 3.21·107, f =
6215, g = 0.1279·10-6, h = 7737, j = 29.7·107, k = 8601, r = 0.994, s =
3.208·1060

The equilibrium constant is related to the temperature according
to the equation of van t’Hoff (32):

K = A·exp(-?H0/RT)

36