intro

• Dynamic equilibrium: a balance between 2 opposite processes occuring at the same rate. reactions that go both ways
• Conditions that must be met for eq:

  • Macroscopic (observable) properties are constant
  • ie: pH, temp., color, etc
  • Closed system - E exchanged, not matter
  • gas reaction must have a lid
  • Rate of forward and reverse reactions are the same
• products favored:

  • products are mostly made
  • Kc > 1
  • > 50%
• reactant favored:

  • reactants are mostly made
  • Kc < 1
  • < 50%
• products are equal to reactants:

  • = 50 %
  • Kc = 1
• equilibrium must be both:

  1. a reversable process (reaction)
  2. closed system (exchange of energy only)
• I - initial concentration

  C - change in concentration

  E - equilibrium
• Kc = equilibrium constant

  • a constant value provided by a mathematical relationship over a range of concentrations at a specific temperature
• is temperature is changes, Kc is changes
• Equilibrium law expression:

  • in a chemical equilibrium there is a constant ratio between the concentration of the products and the concentration of the reactants
  • ex:

  [C]c[D]d

  Kc = ------------

  [A]a[B]b
• solids and liquids are pure substances with fixed concentrations, therefore do not include them in the Kc expression, only aq and g
• Kc↑ = product favored
• Kc↓= reactant favored