Rates of reaction

• What is the definition of the rate of reaction?


  It is a measure of how fast a reaction proceeds.
• What factors affect the rates of reactions?


  • Concentration
  • Surface area
  • Temperature
  • Catalysts
• How does lower concentration affect the rate of reaction?


  Lower concentration results in fewer particles per volume, leading to fewer collisions per second.
• How does higher concentration affect the rate of reaction?


  Higher concentration increases the number of particles per volume, resulting in more collisions per second.
• How does surface area influence the rate of reaction?


  More exposed particles lead to more collisions per second, resulting in a faster reaction.
• What effect does temperature have on the rate of reaction?


  Higher temperature gives particles more energy, increasing the frequency of collisions and thus the reaction rate.
• What are the characteristics of endothermic and exothermic reactions?


  • Endothermic: Absorbs energy, requires activation energy.
  • Exothermic: Releases energy, often has a negative change in energy.
• What is the role of a catalyst in a reaction?


  Catalysts speed up a reaction by providing an alternative route with lower activation energy without being used up.
• What is an example of a biological catalyst?


  Enzymes are biological catalysts.
• How does a catalyst lower the activation energy?


  By providing an alternative reaction pathway that requires less energy.
• What are the methods to test catalysts?


  • Weighing: Compare the weight before and after the reaction.
  • Filtering: Check for changes after filtering.
  • Reacting: Test if the catalyst has changed or been used up.
• What does weighing a catalyst before and after a reaction determine?


  It shows if the reaction has affected the catalyst.
• What does filtering a catalyst after a reaction help to determine?


  It helps to see if anything has changed, indicating if it is a catalyst.
• What does reacting a catalyst help to determine?


  It helps to see if the catalyst has changed or been used up.