Chemical Reaction Mechanisms
Chemistry ⇒ Chemical Reactions and Equations
Chemical Reaction Mechanisms starts at 11 and continues till grade 12.
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A reaction mechanism consists of the following steps: Step 1: A + B → C (slow), Step 2: C + D → E (fast). What is the rate law for this reaction?
A reaction proceeds via the following steps: Step 1: A + B → C (slow), Step 2: C + D → E (fast). If the concentration of D is doubled, what happens to the rate of the reaction?
Define the term 'intermediate' in the context of a reaction mechanism.
Describe the difference between a reaction intermediate and a transition state.
A reaction mechanism consists of the following steps: Step 1: A + B → C (slow), Step 2: C + D → E (fast). What is the rate law for this reaction?
A reaction proceeds via the following steps: Step 1: A + B → C (slow), Step 2: C + D → E (fast). If the concentration of D is doubled, what happens to the rate of the reaction?
In a proposed mechanism, the first step is fast and reversible, and the second step is slow. Which step is likely to be the rate-determining step?
In the following mechanism, identify the intermediate: Step 1: NO2 + F2 → NO2F + F, Step 2: NO2 + F → NO2F
The rate law for a reaction is found to be rate = k[A][B]. Which of the following mechanisms is consistent with this rate law? (1) A + B → products (single step), (2) A → intermediate, intermediate + B → products, (3) 2A + B → products, (4) B → intermediate, intermediate + A → products
The rate law for a reaction is rate = k[A]2. Which of the following could be the molecularity of the rate-determining step? (1) Unimolecular, (2) Bimolecular, (3) Termolecular, (4) Tetramolecular
The reaction 2NO2 → 2NO + O2 is found to be second order in NO2. Which of the following could be the rate law? (1) rate = k[NO2], (2) rate = k[NO2]2, (3) rate = k[NO2][O2], (4) rate = k[NO2][NO]
Which of the following best describes an elementary step in a reaction mechanism? (1) A single molecular event, (2) The overall reaction, (3) The rate-determining step, (4) The slowest step
A catalyst increases the rate of a reaction by providing an alternative pathway with ______ activation energy.
A reaction mechanism must be consistent with the observed ______ law.
The presence of a catalyst changes the ______ of a reaction but not the overall enthalpy change.
The slowest step in a reaction mechanism is called the ______-determining step.
True or False: A catalyst can change the mechanism of a reaction.
True or False: Catalysts appear in the overall balanced equation of a reaction.
True or False: The molecularity of an elementary step can be fractional.
True or False: The overall rate law for a reaction can always be deduced from the stoichiometry of the overall equation.
