The rate law for the 3rd order reaction of the type *A + 2B* → *P* is:

Using the same logic described in a previous article, we can rewrite the rate law as:

where *a* = [*A _{0}*] and

*b*= [

*B*].

_{0}Integrating the above equation throughout, we have

Substituting the partial fraction expression in eq15 and after some algebra, we have,

###### Question

How to compute ?

###### Answer

Note that the integrand in the 5th equality can be obtained by differentiating the last term using the quotient rule.