Equilibria

• In reversible reaction - explain forward reaction in terms of conc. and time

  In forward reactions the reactants are used up quickly which overtime will cause the reactants concentration to drop and products conc to increase - reach equilibrium with backward reaction
• In reversible reaction - explain the backward reaction in terms of conc. and time

  In backward reaction the reactants are formed slow at first but over time the reactant concentration will increase while product conc will decrease and reach equilibrium with forward reaction
• What is dynamic equilibrium?

  When the rate of the forward reaction is equal to the rate of the backward reaction in a closed system. Each of the concentrations remain constant
• What is Le Chatelier's Principle?

  If a reaction at equilibrium is subject to a change in concentration, temperature, pressure - equilibrium will move to counteract the change
• How does a catalyst effect equilibrium?

  -> speeds up the rate of both forward and backward reactions equally

  • has no effect on equilibrium and yield
• -

  
• What is Kc?

  Equilibrium Constant
• How do you calculate Kc?

  Kc = products/reactants
• How do you calculate units for Kc?

  Placing the units of each compound over and under the line and cancel each other out.

  • Invert units if more units under
  • If more above do nothing
• What acronym is used to find conc. of species in equilibrium?

  Inital moles

  Change

  Equilibrium
• What value effects Kc?

  -> Temperature

  • increasing temp - shift to endothermic side -> cause Kc to decrease
  • decreasing temp - shift to exothermic side -> cause Kc to increase
• How does concentration and catalysts affect Kc?

  -> both have NO affect on Kc