Interpretation:
The mechanisms which are compatible with the rate law have to be chosen.
Concept Introduction:
Steady-state approximation:
Once the steady state condition is reached, the rate of formation of the intermediate is equal to the rate of destruction of the intermediate.
Explanation of Solution
(a) The accepted mechanism:
The rate determining step is the slowest step in the mechanism. Thus, the rate of the reaction is given below.
Applying the steady-state approximation on the intermediates
At steady state condition, the rate of formation of the intermediate is equal to the rate of destruction of the intermediate.
Now,
Because the rate of step
Now,
Now, the rate law can be modified as given below.
Assumption:
It is conceivable that the recombination of
Therefore, the rate law of the reaction is
(b) The accepted mechanism:
The rate determining step is the slowest step in the mechanism. Thus, the rate of the reaction is given below.
This rate law is not consistent with the observed rate law.
(c) The accepted mechanism:
The rate determining step is the slowest step in the mechanism. Thus, the rate of the reaction is given below.
Applying the steady-state approximation on the intermediates
At steady state condition, the rate of formation of the intermediate is equal to the rate of destruction of the intermediate.
Now,
Now,
Because the rate of step
Now, the rate law can be modified as given below.
Assumption:
It is conceivable that the recombination of
Therefore, the rate law of the reaction is
(d) The accepted mechanism:
The rate determining step is the slowest step in the mechanism. Thus, the rate of the reaction is given below.
Applying the steady-state approximation on the intermediates
At steady state condition, the rate of formation of the intermediate is equal to the rate of destruction of the intermediate.
Now,
Because the rate of step
Now,
This cannot be solved without any assumption.
So, option (a) and (c) is correct option.
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Chapter 11 Solutions
Chemistry: The Molecular Science
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