Equilibria-NOTES

• What is a reversible reaction?

  A reaction where reactants form products that can reform the original reactants
• How is a reversible reaction represented?

  Using a double arrow

  
• What characterizes the endothermic and exothermic reactions in a reversible system?

  One reaction is endothermic and the opposite is exothermic
• What is dynamic equilibrium in reversible reactions?

  It is when the forward and backward rate of reaction is the same
• What happens to the concentrations of reactants and products at dynamic equilibrium?

  The concentrations remain constant
• In what type of system does dynamic equilibrium occur?

  In closed systems
• What does Le Chatelier’s Principle predict?

  How an equilibrium mixture will change if reaction conditions are altered
• What does Le Chatelier’s Principle state about a system subject to change?

  The system will alter to lessen the effect of that change
• How can Le Chatelier’s Principle be useful in industry?

  It helps to maximize the yield of a desired product
• What effect does increasing temperature have on an endothermic reaction?

  It favors the endothermic reaction and increases the yield of endothermic products
• What happens when temperature is decreased in an exothermic reaction?

  It favors the exothermic reaction and increases the yield of exothermic products
• What is the effect of increasing pressure in a reaction?

  It favors the side with fewer moles
• What is the effect of decreasing pressure in a reaction?

  It favors the side with more moles
• How does increasing the concentration of reactants affect the reaction?

  It favors the reaction that produces the products
• What happens when the concentration of products is decreased?

  It favors the reaction that reforms the reactants
• How do catalysts affect the equilibrium position?

  Catalysts do not affect the equilibrium position
• What do catalysts do in a reaction?

  They allow equilibrium to be reached faster
• What does the equilibrium constant \( K_c \) indicate?

  The position of equilibrium for a reaction at a certain temperature

  
• When does the value of \( K_c \) change?

  When the reaction conditions change
• How is \( K_c \) calculated?

  By dividing the concentration of products by the concentration of reactants
• What happens to the number of moles in the \( K_c \) expression?

  Each substance is raised to a power equal to the number of moles
• How does the equilibrium constant's units vary?

  The units depend on the chemical reaction
• What affects the value of \( K_c \)?

  Changing the reaction temperature
• What does the value of \( K_c \) not change with?

  Concentration change or use of a catalyst
• What is the relationship between temperature and the equilibrium position?

  Changing temperature results in different concentrations of reactants and products