Reaction Profiles

• What is the minimum amount of energy required for a successful collision in a chemical reaction called?

  Activation energy
• Why must atoms or particles collide in a chemical system?

  To react with each other
• What factors are analyzed when considering collisions in chemical reactions?

  Energy, orientation, and number of collisions per second
• How does activation energy vary among different reactions?

  It differs based on the chemical identities involved
• What does a higher activation energy indicate about a reaction?

  It requires more energy to start
• What do energy profiles represent in chemical reactions?

  The relative energies of the reactants and products
• On which axis is the energy of reactants and products displayed in energy profiles?

  1. axis
• What does the x-axis represent in energy profile diagrams?

  The progress of the reaction
• How can you identify whether a reaction is exothermic or endothermic from an energy profile diagram?

  By the direction of the arrows (downwards for exothermic, upwards for endothermic)
• What does a negative change in energy indicate in an exothermic reaction?

  The energy of the products is lower than that of the reactants
• What does a positive change in energy indicate in an endothermic reaction?

  The energy of the products is higher than that of the reactants
• What should you be able to do with reaction profile diagrams for both exothermic and endothermic reactions?

  Draw clear and fully labeled diagrams
• How can you identify a reaction from its reaction profile?

  By analyzing the shape and direction of the energy change