Kinetics

• What is the focus of this revision video?

  Kinetics for AQA
• Who is the presenter of the video?

  Chris Aris
• What is the purpose of the PowerPoints mentioned?

  To aid in revision on kinetics
• What must happen for a reaction to occur?

  Particles must collide
• How is rate defined in kinetics?

  Change in concentration per unit time
• What is the formula for rate?

  Rate = amount of reactant used / time
• Why do most collisions not lead to a reaction?

  Particles bounce off without reacting
• What is required for a reaction to occur after a collision?

  Correct orientation and sufficient energy
• What is activation energy?

  Minimum energy required for a reaction
• What does an energy profile diagram show?

  Energy changes from reactants to products
• What happens to bonds during a reaction as energy increases?

  Bonds stretch and break
• How is activation energy represented in an energy profile diagram?

  As the difference between reactants and peak energy
• What does a low activation energy indicate?

  Less energy is needed for a reaction
• What does the Maxwell-Boltzmann distribution illustrate?

  Energy distribution in gas particles
• What does the area under the Maxwell-Boltzmann curve represent?

  Total number of molecules
• What is the most likely energy of a particle in a sample?

  The peak of the Maxwell-Boltzmann curve
• How does the mean energy of particles compare to the most likely energy?

  Mean energy is slightly to the right
• What does the activation energy line indicate on the Maxwell-Boltzmann curve?

  Energy required for particles to react
• What happens to the rate of reaction when temperature increases?

  More particles exceed activation energy
• How does temperature affect the Maxwell-Boltzmann distribution curve?

  Shifts to the right with lower peak
• What is the effect of decreasing temperature on particle energy?

  Fewer particles exceed activation energy
• Why do reactions occur faster at higher temperatures?

  More frequent and energetic collisions
• What happens to particle spacing at higher pressure?

  Particles are closer together
• How does concentration affect the rate of reaction?

  Higher concentration increases collision frequency
• What is the role of a catalyst in a reaction?

  Provides an alternative pathway with lower activation energy
• What is a characteristic of catalysts after a reaction?

  They remain chemically unchanged
• How does a catalyst affect the Maxwell-Boltzmann distribution curve?

  Shifts activation energy to the left
• What happens to the activation energy in the presence of a catalyst?

  It is lowered
• How can the rate of reaction be measured experimentally?

  By timing precipitate formation
• What is a common method to measure gas production?

  Using a gas syringe
• What is a potential issue with measuring precipitate formation?

  Difficulty in determining when it disappears
• What must be used when measuring toxic gas production?

  A fume cupboard
• What is the significance of repeating experiments with different conditions?

  To monitor changes in gas production
• What are the key factors affecting the rate of reaction?

  • Temperature
  • Concentration
  • Pressure
  • Presence of catalysts
• What is the relationship between temperature and reaction rate?

  • Higher temperature increases kinetic energy
  • More particles exceed activation energy
  • Leads to more frequent and energetic collisions
• How does concentration affect reaction rate?

  • Higher concentration means more particles in the same volume
  • Increases the frequency of collisions
  • Leads to a higher chance of reaction
• What is the role of catalysts in chemical reactions?

  • Increase reaction rate
  • Provide an alternative pathway with lower activation energy
  • Remain unchanged after the reaction
• How can the rate of reaction be measured in experiments?

  • Timing precipitate formation
  • Measuring mass loss for gas production
  • Measuring volume of gas produced using a gas syringe