Topic 10 and 11: Equilibrium I

• equilibrium is established when:


  concentrations are not the same

  forward and backward reaction match

  no further change in concentration
• 2 conditions met for dynamic equilibrium 


  reaction takes place in a closed container/ system

  reaction is reversable
• factors that affect the position of equilibrium

  temperature

  catalyst

  concentration

  pressure
• effect of concentration on equilibrium 


  increasing concentration of A produces more C and D

  it will keep moving forward and back until a new equilibrium is formed

  rate of forward reaction increases until more product is formed

  equilibrium will move to the right

  
• effect of pressure on equilibrium 


  if you decrease pressure the equilibrium will shift to the side with more molecules

  if molecules are the same on both sides, increasing/ decreasing pressure will have no effect

  
• effect of temperature on the equilibrium 


  increase temperature the equilibrium will shift to the left

  decrease temperature the equilibrium will shift right

  position of equilibrium will oppose that increase in temperature this means that it will move to the endothermic reaction

  decrease temperature equilibrium will move to the exothermic reaction
• homogenous system


  all reactants and products in the same state
• heterogenous system 


  reactants and products in different states
• harbour process


  optimum conditions:

  lower temprature and higher pressure

  drawbacks:

  lower temp causes slower rate of reaction

  higher pressure is expensive

  compromise:

  250 atm and 450 degrees
• contact process 


  optimum conditions:

  lower temperature and higher pressure

  compromise:

  2 atm and 45 degrees
• effect of catalyst on equilibrium 


  equilibrium will stay the same

  rate of reaction increases both ways

  adding a catalyst will reduce the time taken to establish an equilibrium
• increasing temperature 


  will shift to the endothermic side (positive)
• decreasing temperature 


  will shift to the exothermic side (negative)
• the concentration of a solid at a given temperature is determined by its density

  this will remain constant
• partial pressure = mole fraction times by total pressure
• mol fraction = number of moles of A divided by total number of mols of gas