kinetics

• What must happen for a reaction to occur according to collision theory?

  Particles must collide.
• How is the rate of reaction defined?

  Rate is the change in concentration or amount of a reactant or product per unit time.
• What is the formula for calculating the rate of reaction?

  Rate = amount of reactant used or product made / time
• Why do most collisions between particles not lead to a reaction?

  Most collisions do not have the correct orientation or sufficient energy.
• What is activation energy?

  Activation energy is the minimum amount of energy required for a reaction to occur.
• How can an energy profile diagram be used in kinetics?

  It shows the energy changes during a reaction from reactants to products.
• What does the activation energy represent on an energy profile diagram?

  It is the difference between the energy of the reactants and the peak of the reaction profile.
• How does a low activation energy affect a reaction?

  It requires less energy to break bonds and typically involves less heat energy.
• What does the Maxwell-Boltzmann distribution illustrate?

  It shows the distribution of kinetic energy among gas particles.
• What does the peak of the Maxwell-Boltzmann distribution represent?

  The most likely energy of a particle in a sample.
• How does the mean energy of particles differ from the most likely energy in a Maxwell-Boltzmann distribution?

  The mean energy is always slightly to the right of the most likely energy.
• What happens to the area under the Maxwell-Boltzmann curve when the temperature increases?

  The area under the curve remains the same, but the shape shifts to the right.
• How does temperature affect the rate of reaction according to collision theory?

  Higher temperatures increase the kinetic energy of particles, leading to more frequent and energetic collisions.
• What is the effect of increasing pressure on the rate of reaction?

  Increasing pressure brings particles closer together, increasing the chance of collisions.
• How does concentration affect the rate of reaction?

  Higher concentration means more particles in the same volume, leading to more frequent collisions.
• What is the role of a catalyst in a chemical reaction?

  A catalyst increases the rate of reaction by providing an alternative pathway with lower activation energy.
• How does a catalyst affect the Maxwell-Boltzmann distribution?

  A catalyst shifts the activation energy to the left, increasing the area of particles with sufficient energy to react.
• How can the rate of reaction be measured experimentally when a precipitate forms?

  By timing how long it takes for the precipitate to obscure a marked cross.
• What is a limitation of measuring the rate of reaction using the disappearing cross method?

  It can be difficult to determine exactly when the cross has disappeared, leading to errors.
• How can mass loss be used to measure the rate of reaction?

  By measuring the decrease in mass as gas escapes during the reaction.
• What is a method for measuring the volume of gas produced in a reaction?

  Using a gas syringe to measure the volume of gas over a specific period of time.
• What should be done if the gas produced in a reaction is toxic?

  A fume cupboard should be used to ensure safety.
• What are the key factors that affect the rate of reaction?

  • Temperature
  • Concentration
  • Pressure
  • Presence of catalysts
• What are the characteristics of a catalyst?


  • Increases the rate of reaction
  • Provides an alternative pathway with lower activation energy
  • Remains chemically unchanged at the end of the reaction
• What is the relationship between temperature and reaction rate?

  • Higher temperatures increase kinetic energy
  • More frequent and energetic collisions occur
  • Small increases in temperature lead to large increases in reaction rate
• How does concentration affect the likelihood of collisions in a reaction?

  • Higher concentration means more particles in the same volume
  • Increased chance of collisions
  • Higher likelihood of reactions occurring
• How does pressure influence the rate of reaction in gases?

  • Increasing pressure brings particles closer together
  • Higher chance of collisions
  • Increased likelihood of reactions occurring
• What is the significance of the area under the Maxwell-Boltzmann curve?

  • Represents the total number of molecules in the sample
  • Important for understanding energy distribution