Factors Affecting Rates of Reaction

• What must particles do to react?

  Collide with enough energy
• How does collision frequency affect reaction rates?

  More collisions increase the reaction rate
• What happens to the reaction rate when collision frequency is doubled?

  The reaction rate also doubles
• What is the minimum energy required for particles to react called?

  Activation energy
• Why do particles need activation energy?

  To bond and break bonds to start reactions
• What are the four factors that affect the rate of reaction?

  • Temperature
  • Concentration of a solution or pressure of a gas
  • Surface area
  • Presence of a catalyst
• How does increasing temperature affect reaction rates?

  Particles move faster and collide more frequently
• What is the effect of faster-moving particles on collision energy?

  More collisions have enough energy to react
• How does increasing concentration affect reaction rates?

  More particles lead to more frequent collisions
• What happens when the pressure of a gas is increased?

  Particles occupy a smaller space, increasing collisions
• How does increasing surface area affect reaction rates?

  More area allows for more frequent collisions
• What is the effect of breaking a solid reactant into smaller pieces?

  It increases the surface area for collisions
• What is a catalyst?

  A substance that speeds up a reaction
• How do catalysts affect activation energy?

  They decrease the activation energy needed
• What do catalysts provide to lower activation energy?

  An alternative reaction pathway
• What are enzymes?

  Biological catalysts in living organisms
• Why is understanding reaction rates important?

  It helps explain how reactions occur faster
• What is the relationship between particle collisions and reaction rates?

  • More frequent collisions increase reaction rates
  • Higher energy collisions lead to successful reactions
  • Successful collisions are necessary for reactions to occur