AP Chemistry Flashcards: Catalysis
Written by AP Content Team, Verified for 2026 AP Exams, Last updated: May 2026
Review key ideas with interactive flashcards. This set includes 14 cards to help you master important concepts.
Why is a catalyst not shown as a reactant or product in an overall balanced chemical equation?
Because a catalyst is consumed and then regenerated during the reaction, its net concentration is constant, so it cancels out of the overall equation.
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Why is a catalyst not shown as a reactant or product in an overall balanced chemical equation?
Because a catalyst is consumed and then regenerated during the reaction, its net concentration is constant, so it cancels out of the overall equation.
How do enzyme catalysts facilitate reactions?
Enzymes bind to reactants, which can orient them favorably for collision or lower the activation energy, often by forming a new reaction intermediate.
An acid (H+) donates a proton to a reactant in step 1, and the proton is released in step 3. What type of catalysis is likely occurring?
This is likely acid-base catalysis, a form of covalent catalysis where new intermediates and elementary steps are introduced.
What are the two main ways a catalyst can increase the rate of a reaction?
A catalyst can increase the reaction rate by either increasing the number of effective collisions or by providing a reaction pathway with a lower activation energy.
What is the primary function of a catalyst in a chemical reaction?
A catalyst increases the rate of a reaction by providing an alternative reaction path or increasing the frequency of effective collisions.
What is surface catalysis?
Surface catalysis occurs when a reactant binds (adsorbs) to the surface of a catalyst, creating new elementary reactions involving the bound intermediate.
How does the introduction of new elementary steps by a catalyst increase reaction rate?
The new elementary steps constitute a different reaction mechanism that has a lower overall activation energy than the uncatalyzed mechanism.
What is the role of a reaction intermediate in a catalyzed reaction?
In many catalyzed reactions, the catalyst helps form a new reaction intermediate that is part of the alternative, lower-energy reaction pathway.
What is a key feature of covalent catalysis?
Covalent catalysis involves the catalyst forming a temporary covalent bond with a reactant, introducing new elementary steps and new reaction intermediates.
How does a catalyst affect the reaction mechanism?
A catalyst provides an alternative reaction mechanism, which is a different sequence of elementary steps for the reaction to follow.
If a species is consumed in the rate-determining step and then regenerated in a later, faster step, what is its role?
This species is a catalyst, as it participates in the mechanism (often in the slowest step) but is regenerated, resulting in no net consumption.
Explain the relationship between a catalyst, a reaction intermediate, and the reaction mechanism.
A catalyst alters the reaction mechanism, often by forming a new reaction intermediate, to provide a pathway with a lower activation energy.
A proposed mechanism involves a reactant binding to a metal surface before reacting. What type of catalysis is this?
This is an example of surface catalysis, where new elementary reactions occur involving an intermediate bound to the catalyst's surface.
What happens to the net concentration of a catalyst during a reaction?
The net concentration of a catalyst remains constant because it is consumed in one elementary step and regenerated in a subsequent step.