Equilibria

• What is a reversible reaction?

  A reaction that can proceed in both the forward and reverse directions.
• What are the features of a dynamic equilibrium?

  • The concentration of reactants and products is constant
  • The rate of the forwards reaction is the same as the rate of the reverse reaction
  • The reactions is in a closed system
• What is a closed system?

  A closed system is a system that does not exchange matter or energy with its surroundings.
• What is Le Chatelier’s Principle?

  When a system in dynamic equilibrium is subjected to change, the position of the equilibrium will shift to oppose the change
• What effect does a higher temperature have on the equilibrium?

  The equilibrium will shift to oppose this and move in the endothermic direction to try to reduce the temperature by absorbing heat.
• What effect does decreasing the temperature have on the equilibrium?

  The equilibrium will shift to oppose this and move in the exothermic direction to try to increase the temperature by giving out heat
• What effect does increasing pressure have on the equilibrium?

  The equilibrium will shift towards the side with fewer moles of gas to oppose the change and thereby reduce the pressure
• What effect does decreasing pressure have on the equilibrium?

  The equiLibrium will shift towards the side with more moles o gas to oppose the change and thereby increase the pressure
• What is a compromise temperature?

  A temperature that gives a reasonable rate and yield
• What if both sides of the equation have the same number of moles?

  Changing pressure will have no effect on the equilibrium
• What effect does increasing the concentration of the reactant have on the equilibrium?

  Equilibrium will shift to the right to make Moore of the product and oppose the increase in concentration of the reactant
• What effect does increasing the concentration of the products have on the equilibrium?

  The equilibrium will shift towards the left to produce more reactants and oppose the change in concentration of products
• What effect does a catalyst have on the equilibrium?

  No effect on the equilibrium, however it increases the rate at which a reaction increases dynamic equilibrium as it increases the speed of both the forward and reverse reaction. The yield is also not affected.
• What is the equilibrium constant?

  The ratio of the concentration of products and reactants an reactants in a reversible reaction- indicates where the equilibrium lies
• What is the only factor that changes the equlibrium constant?

  Temperature
• What is a homogenous reaction?

  A reaction where all reactants and products are in the same phase.
• What is a heterogenous reaction?

  A reaction where reactants and products are in different phases
• What is the Haber process?

  The production of ammonia from nitrogen and hydrogen