The document is a review sheet for Chapter 18 that covers several key concepts: - The collision theory and how temperature, surface area, concentration, and catalysts affect reaction rates - Equilibrium, LeChatlier's principle, and how concentration, temperature, and pressure shifts affect equilibrium - The definitions of endothermic and exothermic reactions and how to calculate heat of reaction - How to calculate equilibrium constants and how they determine favored products or reactants - The definitions of entropy and enthalpy and how they relate to spontaneous reactions

1. Name _______________________________________ Date ______________________
Chapter 18 Review Sheet
• What is the collision theory?
• How does temperature affect reaction rate?
• How does surface area affect reaction rate?
• How does concentration affect reactants?
• How does the presence of a catalyst affect the reaction rate?
• How do catalysts affect the activation energy?
• Know how to interpret reaction rate graphs with and without catalysts

2. • What is equilibrium? How does the rates of the forward reaction compare to the rates
of the reverse reaction?
• What is LeChatlier’s principle?
• What kind of shifts in equilibrium are expected with changes in:
 Concentration
 Temperature
 Pressure
• Know that the amount of energy released or absorbed during a chemical reaction is
the heat of reaction
 Heat of reaction = PE of products – PE of reactants
• What is an endothermic reaction? Is their heat of reaction + or -?
• What is an exothermic reaction? Is their heat of reaction + or -?
• How do you calculate the Keq (equilibrium constant) for an equation
Ex.) aA + bB  cC dD
• How does Keq determine whether the products or reactants are favored at equilibrium?
• What is entropy? What is the entropy trend for systems?
• What is enthalpy? What is the enthalpy trend for systems?
• Spontaneous vs. non spontaneous reactions