For a reaction that proceeds by the following two-step mechanism, the first step is known to be rate-determining.
Step 1 (slow): P + Q → R
Step 2 (fast): R + Q → products
Which of the following must be true of the experimentally determined rate law?
a) It is first order in P and second order in Q because Q appears in two elementary steps.
b) It is first order in P and first order in Q because both species collide in the slow step.
c) It includes the intermediate R, since R reacts again immediately after it is formed.
d) It is first order in P but zero order in Q because Q is regenerated in the mechanism.