rates of reaction

• What is activation energy?

  The amount of energy required for the reactants to react
• What is a catalyst?

  An additional substance that adjusts the rate of a chemical reaction but is not used up in the reaction
• What does collision theory state?

  Reactants must collide with sufficient activation energy and at the right orientation for a reaction to occur
• How is concentration defined in chemistry?

  The amount of particles in a specific volume, measured in moles per litre (mol L-1)
• What is the reaction rate?

  The amount of reactions occurring per unit time, usually per second
• What does surface area refer to in a chemical context?

  The amount of 'visible' area or surface of an object or substance
• How does temperature affect reaction rates?

  Higher temperatures increase the kinetic energy of particles, leading to more collisions and a faster reaction rate
• What happens to reaction rates as temperature decreases?

  Particles move slower, resulting in fewer collisions per second and a slower reaction rate
• What is the relationship between temperature and time in a reaction?

  As the temperature increases, the time decreases, and vice versa
• What is the concentration equation?

  c = n / V

  • c = concentration
  • n = moles
  • V = volume
• What does 'c' represent in the concentration equation?

  Concentration measured in mol L-1
• What does 'n' represent in the concentration equation?

  Number of moles measured in moles (mol)
• How does high concentration affect particle collisions?

  High concentration means smaller distances between particles, leading to more frequent collisions
• What happens when reactant concentrations are low?

  The distance between particles is larger, resulting in fewer collisions per second
• What happens to the reaction rate when the concentration of reactants is increased?

  • The distance between particles decreases
  • Collisions become more frequent
  • Therefore, the reaction rate increases
• What happens to the reaction rate when the concentration of reactants is decreased?

  • The distance between particles increases
  • Collisions become less frequent
  • Therefore, the reaction rate decreases
• How does increasing the surface area affect the rate of reaction?

  Increasing the surface area increases the rate of reaction
• What happens when a solid is ground into smaller pieces?

  Previously hidden areas within the solid become exposed, increasing the reaction rate
• How do finely ground solids compare to solid lumps in terms of surface area?

  Finely ground solids have a vastly increased surface area compared to solid lumps of the same mass
• Does changing the surface area affect the energy of the particles?

  No, changing the surface area does not affect the energy of the particles
• What do catalysts do in a chemical reaction?

  Catalysts increase the rate of reactions by providing an alternate way for the reaction to occur that requires less activation energy
• How do catalysts affect reaction rates?

  Catalysts increase the reactions that occur per second
• what is a catalyst?



  • a substance which speeds up the rate of reaction through lowering the amount of activation energy; does not change the amount of products produced and kc.
  • allows equilibrium to be reached within a shorter period of time.