AP Chemistry Flashcards: Reaction Energy Profile
Written by AP Content Team, Verified for 2026 AP Exams, Last updated: May 2026
Review key ideas with interactive flashcards. This set includes 11 cards to help you master important concepts.
What fundamental processes occur during an elementary reaction?
Elementary reactions typically involve the breaking of some existing chemical bonds and the forming of new ones.
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What fundamental processes occur during an elementary reaction?
Elementary reactions typically involve the breaking of some existing chemical bonds and the forming of new ones.
How is the overall energy change of a reaction represented on an energy profile?
The overall energy change is represented by the difference in energy between the final products and the initial reactants.
What does the peak of a reaction energy profile represent?
The peak of the energy profile represents the transition state, which is the highest-energy point along the reaction coordinate.
Why is the rate of a reaction dependent on temperature?
Reaction rate is temperature-dependent because temperature affects the proportion of collisions that possess enough energy to overcome the activation energy and reach the transition state.
What is a reaction energy profile?
A reaction energy profile is a graph that shows the energy of a system as it proceeds along the reaction coordinate, moving from reactants, through a transition state, to products.
What relationship does the Arrhenius equation describe in the context of reaction energy?
The Arrhenius equation describes the relationship between temperature and the proportion of collisions with sufficient energy to reach the transition state, thereby affecting the reaction rate.
If a reaction energy profile shows products at a higher energy level than reactants, what does this imply about the overall energy change?
This implies the reaction has a positive overall energy change, meaning it is an endothermic reaction that has absorbed energy from the surroundings.
Define the term 'reaction coordinate'.
The reaction coordinate is the axis on an energy profile that plots the energy of the complex set of motions involved in rearranging reactants to form products.
What is activation energy (Ea)?
Activation energy is the energy difference between the reactants and the transition state, representing the minimum energy required for a reaction to occur.
What three key points are depicted along the reaction coordinate on an energy profile?
The energy profile shows the energy of the system as it proceeds from reactants, through a transition state, to products.
On a reaction energy profile, how would you locate the activation energy?
You would find the energy difference between the starting energy level of the reactants and the energy level of the transition state at the peak of the curve.