Reaction Energy Profile - AP Chemistry
Card 1 of 30
What is the effect of particle size decrease on reaction rate?
What is the effect of particle size decrease on reaction rate?
Tap to reveal answer
Increases reaction rate. Smaller particles have greater surface area, increasing collision frequency.
Increases reaction rate. Smaller particles have greater surface area, increasing collision frequency.
← Didn't Know|Knew It →
State the definition of the activated complex in a reaction.
State the definition of the activated complex in a reaction.
Tap to reveal answer
A transitional structure formed during a reaction. This unstable intermediate exists at the energy maximum during bond reorganization.
A transitional structure formed during a reaction. This unstable intermediate exists at the energy maximum during bond reorganization.
← Didn't Know|Knew It →
Identify the term for reactions that release energy to the surroundings.
Identify the term for reactions that release energy to the surroundings.
Tap to reveal answer
Exothermic reactions. These reactions release energy, making products lower in energy than reactants.
Exothermic reactions. These reactions release energy, making products lower in energy than reactants.
← Didn't Know|Knew It →
What does the energy difference between reactants and products indicate?
What does the energy difference between reactants and products indicate?
Tap to reveal answer
The enthalpy change ($\Delta H$) of the reaction. This represents the overall heat absorbed or released in the reaction.
The enthalpy change ($\Delta H$) of the reaction. This represents the overall heat absorbed or released in the reaction.
← Didn't Know|Knew It →
Which direction of enthalpy change (positive/negative) indicates an exothermic reaction?
Which direction of enthalpy change (positive/negative) indicates an exothermic reaction?
Tap to reveal answer
Negative $\Delta H$ indicates exothermic. Energy flows from the system to surroundings when $\Delta H < 0$.
Negative $\Delta H$ indicates exothermic. Energy flows from the system to surroundings when $\Delta H < 0$.
← Didn't Know|Knew It →
What is the definition of activation energy in a chemical reaction?
What is the definition of activation energy in a chemical reaction?
Tap to reveal answer
The minimum energy required to initiate a chemical reaction. This energy barrier must be overcome for reactant bonds to break and form products.
The minimum energy required to initiate a chemical reaction. This energy barrier must be overcome for reactant bonds to break and form products.
← Didn't Know|Knew It →
Which option shows a reaction with a negative $\Delta H$?
Which option shows a reaction with a negative $\Delta H$?
Tap to reveal answer
An exothermic reaction. Negative $\Delta H$ means products are lower in energy, releasing heat.
An exothermic reaction. Negative $\Delta H$ means products are lower in energy, releasing heat.
← Didn't Know|Knew It →
What is the effect of a catalyst on activation energy?
What is the effect of a catalyst on activation energy?
Tap to reveal answer
Catalysts lower the activation energy. They provide alternative pathways with lower energy barriers for reactions.
Catalysts lower the activation energy. They provide alternative pathways with lower energy barriers for reactions.
← Didn't Know|Knew It →
Which part of a reaction energy profile represents the activated complex?
Which part of a reaction energy profile represents the activated complex?
Tap to reveal answer
The peak of the energy curve. The transition state occurs at maximum energy where bonds are breaking and forming.
The peak of the energy curve. The transition state occurs at maximum energy where bonds are breaking and forming.
← Didn't Know|Knew It →
Identify the term for reactions that release energy to the surroundings.
Identify the term for reactions that release energy to the surroundings.
Tap to reveal answer
Exothermic reactions. These reactions release energy, making products lower in energy than reactants.
Exothermic reactions. These reactions release energy, making products lower in energy than reactants.
← Didn't Know|Knew It →
What does the energy difference between reactants and products indicate?
What does the energy difference between reactants and products indicate?
Tap to reveal answer
The enthalpy change ($\Delta H$) of the reaction. This represents the overall heat absorbed or released in the reaction.
The enthalpy change ($\Delta H$) of the reaction. This represents the overall heat absorbed or released in the reaction.
← Didn't Know|Knew It →
State the definition of the activated complex in a reaction.
State the definition of the activated complex in a reaction.
Tap to reveal answer
A transitional structure formed during a reaction. This unstable intermediate exists at the energy maximum during bond reorganization.
A transitional structure formed during a reaction. This unstable intermediate exists at the energy maximum during bond reorganization.
← Didn't Know|Knew It →
What is the significance of the peak in a reaction energy profile?
What is the significance of the peak in a reaction energy profile?
Tap to reveal answer
It represents the transition state. The highest point corresponds to the unstable activated complex formation.
It represents the transition state. The highest point corresponds to the unstable activated complex formation.
← Didn't Know|Knew It →
State the effect of concentration increase on reaction rate.
State the effect of concentration increase on reaction rate.
Tap to reveal answer
Increases reaction rate. More reactant molecules increase collision frequency and reaction rate.
Increases reaction rate. More reactant molecules increase collision frequency and reaction rate.
← Didn't Know|Knew It →
Identify the component of the reaction energy profile that changes with a catalyst.
Identify the component of the reaction energy profile that changes with a catalyst.
Tap to reveal answer
The activation energy ($E_a$). Catalysts only affect activation energy, not the overall enthalpy change.
The activation energy ($E_a$). Catalysts only affect activation energy, not the overall enthalpy change.
← Didn't Know|Knew It →
Which option shows a reaction with energy released as heat?
Which option shows a reaction with energy released as heat?
Tap to reveal answer
An exothermic reaction. Heat release occurs when products form at lower energy than reactants.
An exothermic reaction. Heat release occurs when products form at lower energy than reactants.
← Didn't Know|Knew It →
Which direction of enthalpy change (positive/negative) indicates an endothermic reaction?
Which direction of enthalpy change (positive/negative) indicates an endothermic reaction?
Tap to reveal answer
Positive $\Delta H$ indicates endothermic. Energy flows from surroundings to the system when $\Delta H > 0$.
Positive $\Delta H$ indicates endothermic. Energy flows from surroundings to the system when $\Delta H > 0$.
← Didn't Know|Knew It →
What does a lower peak in the presence of a catalyst indicate?
What does a lower peak in the presence of a catalyst indicate?
Tap to reveal answer
Reduced activation energy. Catalysts create alternative pathways requiring less energy to reach products.
Reduced activation energy. Catalysts create alternative pathways requiring less energy to reach products.
← Didn't Know|Knew It →
Find and correct: 'The transition state has the lowest energy in a reaction.'
Find and correct: 'The transition state has the lowest energy in a reaction.'
Tap to reveal answer
Correct: 'highest energy.'. The transition state represents the maximum energy point during reaction.
Correct: 'highest energy.'. The transition state represents the maximum energy point during reaction.
← Didn't Know|Knew It →
Identify the term for the highest energy point in a reaction energy profile.
Identify the term for the highest energy point in a reaction energy profile.
Tap to reveal answer
Transition state. This point represents the activated complex at maximum potential energy.
Transition state. This point represents the activated complex at maximum potential energy.
← Didn't Know|Knew It →
What is the influence of a catalyst on reaction equilibrium?
What is the influence of a catalyst on reaction equilibrium?
Tap to reveal answer
No change in equilibrium position. Catalysts speed reactions equally in both directions, maintaining equilibrium.
No change in equilibrium position. Catalysts speed reactions equally in both directions, maintaining equilibrium.
← Didn't Know|Knew It →
Find and correct: 'Exothermic reactions have $\Delta H > 0$.'
Find and correct: 'Exothermic reactions have $\Delta H > 0$.'
Tap to reveal answer
Correct: '$\Delta H < 0$'. Exothermic reactions release energy, requiring negative enthalpy change values.
Correct: '$\Delta H < 0$'. Exothermic reactions release energy, requiring negative enthalpy change values.
← Didn't Know|Knew It →
Identify the term for reactions that release energy to the surroundings.
Identify the term for reactions that release energy to the surroundings.
Tap to reveal answer
Exothermic reactions. These reactions release energy, making products lower in energy than reactants.
Exothermic reactions. These reactions release energy, making products lower in energy than reactants.
← Didn't Know|Knew It →
What does the energy difference between reactants and products indicate?
What does the energy difference between reactants and products indicate?
Tap to reveal answer
The enthalpy change ($\Delta H$) of the reaction. This represents the overall heat absorbed or released in the reaction.
The enthalpy change ($\Delta H$) of the reaction. This represents the overall heat absorbed or released in the reaction.
← Didn't Know|Knew It →
State the definition of the activated complex in a reaction.
State the definition of the activated complex in a reaction.
Tap to reveal answer
A transitional structure formed during a reaction. This unstable intermediate exists at the energy maximum during bond reorganization.
A transitional structure formed during a reaction. This unstable intermediate exists at the energy maximum during bond reorganization.
← Didn't Know|Knew It →
What is the significance of the peak in a reaction energy profile?
What is the significance of the peak in a reaction energy profile?
Tap to reveal answer
It represents the transition state. The highest point corresponds to the unstable activated complex formation.
It represents the transition state. The highest point corresponds to the unstable activated complex formation.
← Didn't Know|Knew It →
Which direction of enthalpy change (positive/negative) indicates an exothermic reaction?
Which direction of enthalpy change (positive/negative) indicates an exothermic reaction?
Tap to reveal answer
Negative $\Delta H$ indicates exothermic. Energy flows from the system to surroundings when $\Delta H < 0$.
Negative $\Delta H$ indicates exothermic. Energy flows from the system to surroundings when $\Delta H < 0$.
← Didn't Know|Knew It →
What is the effect of a catalyst on activation energy?
What is the effect of a catalyst on activation energy?
Tap to reveal answer
Catalysts lower the activation energy. They provide alternative pathways with lower energy barriers for reactions.
Catalysts lower the activation energy. They provide alternative pathways with lower energy barriers for reactions.
← Didn't Know|Knew It →
What is the definition of activation energy in a chemical reaction?
What is the definition of activation energy in a chemical reaction?
Tap to reveal answer
The minimum energy required to initiate a chemical reaction. This energy barrier must be overcome for reactant bonds to break and form products.
The minimum energy required to initiate a chemical reaction. This energy barrier must be overcome for reactant bonds to break and form products.
← Didn't Know|Knew It →
Which option shows a reaction with a negative $\Delta H$?
Which option shows a reaction with a negative $\Delta H$?
Tap to reveal answer
An exothermic reaction. Negative $\Delta H$ means products are lower in energy, releasing heat.
An exothermic reaction. Negative $\Delta H$ means products are lower in energy, releasing heat.
← Didn't Know|Knew It →