Question

Consider the following elementary steps that make up the mechanism of a certain reaction: 3A→B+C B+2D→C+F Part A What is the overall reaction? Express your answer as a chemical equation. View Available Hint(s) nothing Part B Which species is a reaction intermediate? View Available Hint(s) Which species is a reaction intermediate? A B C D F Part C What is the rate law for step 1 of this reaction? Express your answer in standard MasteringChemistry notation. For example, if the rate law is k[A][C]3 type k*[A]*[C]^3. View Available Hint(s) Rate = Part D What is the rate law for step 2 of this reaction? Express your answer in standard MasteringChemistry notation. For example, if the rate law is k[A][C]3 type k*[A]*[C]^3. View Available Hint(s) Rate = Provide Feedback

Answer 1

The overall reaction is 3A + 2D → 2C + F. The reaction intermediate is B. The rate laws for step 1 and step 2 are Rate = k*[A]^3 and Rate = k*[B]*[D]^2 respectively.

Step-by-step explanation:

Part A: Overall Reaction

By adding the two given elementary steps:

3A → B + C

B + 2D → C + F

We can find the overall reaction by cancelling species that appear on both sides (intermediates) and combining the remaining species. Doing so, we obtain:

3A + 2D → 2C + F

Part B: Reaction Intermediate

The species that is a reaction intermediate is B, as it is formed in the first step and consumed in the second step.

Part C: Rate Law for Step 1

The rate law for the first elementary reaction can be written as:

Rate = k*[A]^3

Since the first step involves three molecules of A interacting, it is termolecular, and therefore the rate law reflects this with a cubic dependency on the concentration of A.

Part D: Rate Law for Step 2

The rate law for the second elementary reaction can be written as:

Rate = k*[B]*[D]^2

This is because the second step is a bimolecular reaction involving one molecule of B and two molecules of D.

Answer 2

A. 3A + 2D → 2C + F

B. B is an intermediate

C. rate = k[A]³

D. rate = k`[D]²

Step-by-step explanation:

Part A

The overall reaction is the sum of all the elementary steps:

3A→B+C

+

B+2D→C+F

3A + 2D → 2C + F

Part B

A reaction intermediate is one that participates in the elementary steps, but it is not a product. Notice B is produced in the first step and consumed in the second, therefore it is an intermediate species.

Part C

The rate law is the product of the reaction constant, k, times the concentration of the reactants raised to the power of their coefficients in the balanced reaction assuming that it is the slow step in the reaction mechanism.

rate = k[A]³

Part D

Again as in part C:

rate = k [D]² ( B is not included since as we saw it is an intermediate )