Chemical Equilibrium–Topics for Test

Topics for Test – Chemical Equilibrium

  • Graphs representing systems in equilibrium
  • Homogeneous equilibrium
  • Heterogeneous equilibrium
  • Dynamic equilibrium
  • How to write equilibrium concentration expressions for heterogeneous equilibrium
  • What does the magnitude of Kc or Keq tell you
  • Equilibrium constant for reactions with 2 or more elementary steps
  • Multiplying an equation by a coefficient ‘n’ changes Kc to Kc raised to n
  • When Kc = 1 what does it mean?
  • Application of Le Chateliers principle on systems in equilibrium
  • Shift in equilibrium when there is a [concentration] change
  • Shift in equilibrium when concentration is changed by changing volume
  • Shift in equilibrium when an inert gas is added to the reaction mixture
  • Shift in equilibrium when products are removed from the closed equilibrium system
  • Shift in equilibrium when the number of moles of reactants and products are not equal for gaseous system
  • Shift in equilibrium when heat is added or removed in an exothermic or endothermic reaction
  • Shift in equilibrium and catalyst for a reversible reaction
  • Problems – When the equilibrium expression is a perfect square
  • Problems – When K is very very small (applying 100th rule)
  • Problems – When the equilibrium expression is not a perfect square and the use of quadratic equation
  • Problems – When a stress is applied to a system in equilibrium (Le Chatliers principle) new concentration of reactant or product
  • Entropy – definition and prediction based on state of matter, temperature of reactants and products, # of moles of reactants and products
  • Spontaneous reactions
  • Gibbs Helmoltz equation and free energy
  • What is the significance of free energy?
  • What are the conditions for spontaneity of chemical reactions
  • Calculation of Kc from free energy DG = -2.303 RTlog Kc, DG = DH – TDS
  • Temperature at which a system attains equilibrium DG and equilibrium when value = 0
  • DG and equilibrium when value < 0 = -ve
  • DG and equilibrium when value > 0 = +ve
  • DG = 0 the system is in equilibrium.

Solubility Product Topics

  • Equilibrium of sparing soluble salts
  • Solubility product constant Ksp
  • Determination of Ksp from molar solubility
  • Ion product Vs Solubility product
  • Determining molar solubility from Ksp
  • Common ion effect, qualitative explanation and calculation
  • Predicting precipitation, problems
  • Selective precipitation of halides, sulfides, hydroxides, metals
  • Application of knowledge of Ksp
  • Use of complex ion formation in qualitative analysis
  • Separation of metal ions using Ksp