If plotting #ln[A]# vs. time gives a straight line, what is the order of reaction?

1 Answer
Sep 30, 2017

You may want to re-read this...

What is the value for the rate constant #k# at this temperature?


Well, a default rate law would include the reactant(s) in the reaction

#A -> B + C#

and so, one would write

#r(t) = k[A]^m#

as a first guess. And we know that the first-order integrated rate law is

#overbrace(ln[A])^(y) = overbrace(-k)^(m)overbrace(t)^(x) + overbrace(ln[A]_0)^(b)#,

with #[A]# being the concentration of reactant #A# at time #t#, and #k# being the rate constant. #[A]_0# is then the initial concentration of #A# at time zero.

Since using the first-order integrated rate law by plotting #ln[A]# vs. #t# yielded a straight line, this reaction has a rate law of:

#color(blue)(r(t) = k[A])#

because we know #m = 1# at this point. What therefore does #m# signify?