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Rate-Determining Step A multistep reaction can only occur as fast as its slowest

ID: 1068124 • Letter: R

Question

Rate-Determining Step

A multistep reaction can only occur as fast as its slowest step. Therefore, it is the rate law of the slow step that determines the rate law for the overall reaction.

Part A

Consider the following multistep reaction:

Based on this mechanism, determine the rate law for the overall reaction.

Express your answer in standard MasteringChemistry format. For example, if the rate law is k[A]3[B]2 type k*[A]^3*[B]^2.

Part B

Consider the following multistep reaction:

Based on this mechanism, determine the rate law for the overall reaction.

Express your answer in standard MasteringChemistry format. For example, if the rate law is k[C]3[D]2 type k*[C]^3*[D]^2.

A+BAB(slow) A+ABA2B(fast) 2A+BA2B(overall)

Explanation / Answer

A)
rate law depends on the slowest step
so,
rate = k[A][B]

Answer:
k*[A]*[B]


B)
rate law depends on the slowest step
so,
rate = k'[CD][D]

but CD is intermediate. So use step 1
kc = [CD]/[C][D]
[CD] = kc [C][D]

put this in expression of rate
rate = k'kc [C][D][D]
= k*[C][D]^2

Answer:
k*[C]*[D]^2