Exo and Endothermic Reactions

• What are the two types of reactions discussed in the video?

  Exothermic and endothermic reactions
• How can exothermic and endothermic reactions be represented?

  Using reaction profiles
• What is the importance of activation energy in chemical reactions?

  It is the minimum energy needed for reactants to collide and react
• What does each molecule in a reaction hold?

  A different amount of energy in their chemical energy stores
• In the reaction of methane and oxygen, how does the energy of products compare to reactants?

  The products have less energy than the reactants
• How would you represent the reaction of methane and oxygen on a reaction profile?

  Reactants on the left and products lower down on the right
• What happens to energy in an exothermic reaction?

  Energy is released to the surroundings
• What is the most common type of exothermic reaction?

  Combustion reactions
• How would you represent an endothermic reaction on a reaction profile?

  Reactants on the left and products higher up on the right
• What is an example of an endothermic reaction?

  Breaking down calcium carbonate into calcium oxide and carbon dioxide
• What does the difference in height on a reaction profile for an endothermic reaction represent?

  The energy absorbed during the reaction
• What is activation energy represented as on a reaction profile?

  The increase in energy from the reactants to the highest point on the curve
• How does activation energy differ between exothermic and endothermic reactions?

  Both types require activation energy to start the reaction
• How would you adjust a reaction profile to show a higher activation energy?

  Make the curve go higher
• How would you label the chemicals in a specific reaction on a reaction profile?

  By writing the actual chemicals from the equations instead of just reactants and products
• What are the key characteristics of exothermic reactions?

  • Release energy to the surroundings
  • Commonly involve combustion reactions
  • Products have less energy than reactants
• What are the key characteristics of endothermic reactions?

  • Absorb energy from the surroundings
  • Require heat to proceed
  • Products have more energy than reactants
• What is the role of activation energy in chemical reactions?

  • Minimum energy needed for reactants to collide
  • Required for both exothermic and endothermic reactions
  • Shown as a peak in reaction profiles