Equilibria

• What type of reactions are reversible?

  Reactions where products can reform reactants
• How is a reversible reaction represented?

  Using a double arrow
• What characterizes the two reactions in a reversible system?

  One is endothermic, the other exothermic
• What is dynamic equilibrium?

  When forward and backward reaction rates are equal
• What happens to concentrations at dynamic equilibrium?

  Concentrations of reactants and products remain constant
• In what type of system does dynamic equilibrium occur?

  Closed systems
• What does Le Chatelier’s Principle predict?

  How an equilibrium mixture changes with conditions
• What does Le Chatelier’s Principle state?

  The system alters to lessen the effect of change
• How can industries use Le Chatelier’s Principle?

  To maximize the yield of desired products
• What effect does increasing temperature have on reactions?

  It favors the endothermic reaction
• What happens when temperature is decreased in a reaction?

  It favors the exothermic reaction
• What is the effect of increasing pressure on a reaction?

  It favors the side with fewer moles
• What happens when pressure is decreased in a reaction?

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

  It favors the production of products
• What is the effect of decreasing product concentration?

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

  Catalysts do not affect equilibrium position
• What do catalysts do to the rate of reaching equilibrium?

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

  The position of equilibrium at a certain temperature
• When does the value of \( K_c \) change?

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

  Concentration of products divided by reactants
• What happens to the number of moles in the \( K_c \) expression?

  Each substance is raised to the power of moles
• What affects the units of \( K_c \)?

  The chemical reaction involved
• What does changing temperature do to \( K_c \)?

  It affects the value of \( K_c \)
• How does concentration change affect \( K_c \)?

  It does not affect the value of \( K_c \)
• How do catalysts influence \( K_c \)?

  Catalysts do not affect the value of \( K_c \)