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gfd43tg

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## Homework Statement

The rate law for the reaction

is found from experiment to be

Suggest a mechanism consistent with the rate law.

## Homework Equations

## The Attempt at a Solution

Here is the webpage with the solution

http://www.umich.edu/~elements/07chap/frames.htm

Here is the solution

**Rate Laws**

**Relative Rates**

**Net Rates:**Rate of Formation of Product

Need to find an expression for CA* because we cannot easily measure the concentration of A*, use PSSH to solve for CA*.

Solving for CA*

Substituting for CA* in Equation (4) the rate of formation of B is

Relative rates overall

My question is, why do they go about finding the rate law for B from the original reaction, instead of by steps. The way I thought to do this was to find ##r_{A}## from the elementary steps, exactly the same way they found ##r_{A^{*}}##.

##r_{1A} = -k_{1}C_{A}^2##

##r_{2A} = -k_{2}C_{A}C_{A^*}##

##r_{A} = r_{1A} + r_{2A}##

However, there is some complication with ##r_{A2}##. Since the reaction is ##A^* + A \rightarrow A + A##, How can I do the reaction rate of A assuming irreversible? I don't know if it should be ##r_{A2} = -k_{2}C_{A}C_{A^*}## or ##r_{A2} = -k_{2}C_{A}C_{A^*} + k_{2}C_{A}^2##

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