Question

In a reaction, compounds A and B combine to form compounds C and

d. Experimental data shows that the reaction is third-order. Which rate law could describe this reaction?

Answer 1

We are given two compounds which are A and B. These compounds combine to form compounds C and D. And the experimental data shows that the reaction is third-order. This means that the reaction can either be:

1) A + 2B ===> C + D
or
2) 2A + B ===> C + D

So, the rate law is

1) k = [A][B]^2
or
2) k = [A]^2[B]

Answer 2

The integrated rate law for third order reaction is K[A][B]^2.  For third order reactions, the sum of the exponents in the reaction must be equal to 3. Reactant does not have any exponent because its concentration is directly proportional to the rate of the reaction.