rate of reactions

• rate of reaction equation?

  rate of reaction = change in con, vol or mass / time
• temperature effect?

  • affects solid, liquid and gas
  • increases frequency of collisions - particles move faster
  • increase number of particles with equal or greater energy than activation energy
• surface area effect?

  • affects solids
  • increases frequency of collisions - more reactant particles exposed
• concentration effects?

  • affects liquids
  • increases frequency of collisions - more reactant particles in a fixed volume = closer together
• pressure effect?

  • affects gases
  • increases frequency of collisions - particles are closer together
• rate of reaction graphs?

  • steep gradient = fast reaction
  • decrease in gradient = reaction slows
  • line flattens out = no more product is formed
• catalyst?

  • substance that increases the rate of reaction without being used up
  • lowers activation energy (provides alternate pathway)
  • weakens chemical bonds