Kc

• Equilibrium constant, K

  A measure of the position of equilibrium; the magnitude of an equilibrium constant indicates whether there are more reactants or more products in an equilibrium system
• when expressing Kc you must put products over reactants and use square brackets
• square brackets are shorthand for the 'concentration of'
• a, b, c, d are the balancing numbers in the overall equation and the powers in Kc expression
• a Kc value of 1 tells us a position of equilibrium is halfway between reactants and products
• a Kc value >1 indicates a position of equilibrium towards products
• a Kc value <1 indicates a position of equilibrium towards reactants
• the larger the Kc value

  • the further the position of equilibrium lies to the right hand side
  • the greater the concentrations of the products compared to the reactants
• Kc is for concentration
• aA + bB = cC +dD so C and D go over A and B because products over reactants
• Bigger Kc value, equilibrium on right
• Smaller Kc value, equilibrium on left
• Kc only changes if you change the temp
• unit is mol per dm3