Chemistry Reference
In-Depth Information
If a plot of equation (9.1) is made, with
t
on the horizontal axis and
ln[
a
/(
a
x
)] on the vertical axis, a straight line passing through the origin
will be obtained for a reaction obeying first-order kinetics. The slope of this
straight line will be equal to
k
, the
rate constant
for the reaction (see Figure
9.1).
a
ln
Slope =
k
(
a
-
x
)
t
Figure 9.1
Graph of ln[a/(a
x)] vs t.
x
) vs
t
will yield a straight line the
slope of which is negative and equal to
For equation (9.2), a plot of ln(
a
k
, and the intercept with the
vertical axis equal to ln
a
(see Figure 9.2).
Slope = -
k
ln(
a
-
x
)
t
Figure 9.2
Graph of ln(a
x) vs t.
The rate constant,
k
, is a very important measure of a reaction rate
and has the dimension of time
1
for a first-order process. This can be shown
