Question

Consider the mechanism. step 1:step 2:overall:2a⟶bb c⟶d2a c⟶dslowfast determine the rate law for the overall reaction, where the overall rate constant is represented as k.

Answer 1

Answer:

Rate: R = k [A]²

Explanation:

The rate law equation for a given complex chemical reaction is given as the product of molar concentrations of the reactant raised to the power their respective partial reaction orders. The sum of the partial reaction orders is equal to the overall order of reaction.

For a complex reaction, the rate law is generally determined by the slowest step, which is known as the rate-determining step.

Given reaction mechanism:

Step 1: 2 A⟶ B,               slow step

Step 2: B+ C⟶ D,            fast step

Overall: 2 A + C ⟶ D

In this given reaction mechanism, the step 1 is the slow step and thus the rate determining step.

Therefore, the rate law for the given mechanism is:

Rate: R = k [A]²

Here, k is the overall rate constant

Also, the overall order of the reaction = 2

Therefore, the given chemical reaction is said to be second order reaction.