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of log([BHP]/[BH]) for any given point along the abcissa
as ionic strength is increased, and (2) the decrease in
the slopes of the lines as the ionic strength is increased.
Two explanations for the change in slope may be advanced.
The value of q may be indeed changing from 2 to 1, for the
intercalation reaction, as the ionic strength is increased.
If this is true, then either the overall stoichiometry is
changing such that mq ^ 4 or, the stoichiometry is remaining
constant and m is becoming equal to 4 while q is decreasing
to 1. A more likely explanation can be advanced on the basis
of relative changes of K and K If K and KT do not change
in the same manner as the ionic strength is varied, then
what we may be observing is an apparent change in q for
intercalative binding when, in reality, the apparent change
is due to an overlapping of surface binding manifestations
with intercalative binding. Assume that the values of m and
q remain unchanged for each type of binding, then, the real
slopes of the two line segments will remain constant and
their point of intersection will be dependent on the ratio
of Ks to K. For example, in one extreme case there is
essentially no intercalative binding, K /K is very large,
b -L
and only the line having slope 1 will be observed. At the
other extreme, Ks/KI would be very small when only inter
calative binding occurs and a single line having slope 2
would be seen. If the system is perturbed in a manner which
caused K to decrease more rapidly than KT the point of
intersection of the two lines will reflect the change in