Exo/endothermic reactions

• What is meant by an exothermic reaction?

  It transfers energy to the surroundings
• What happens to the temperature of surroundings during an exothermic reaction?

  The temperature increases
• What is a common example of an exothermic reaction?

  Combustion or burning
• How do scientists represent energy changes in reactions?

  By drawing energy profile diagrams
• What does an energy profile diagram for an exothermic reaction show about the products and reactants?

  Products have less energy than reactants
• What does the difference in energy between reactants and products indicate in an exothermic reaction?

  The energy released to the surroundings
• Name two other examples of exothermic reactions.

  Oxidation and neutralization
• What are two uses of exothermic reactions?

  Hand-warmers and self-heating cans
• What is meant by an endothermic reaction?

  It takes in energy from the surroundings
• What happens to the temperature of surroundings during an endothermic reaction?

  The temperature decreases
• What is a good example of an endothermic reaction?

  Thermal decomposition
• How do the energy profiles of exothermic and endothermic reactions compare?

  Both rise to a peak called activation energy
• What is activation energy?

  The minimum energy needed for reactions
• How is activation energy represented on an energy profile diagram?

  From reactants to the peak of the curve
• What is the significance of activation energy in chemical reactions?

  Reactions occur when particles collide with sufficient energy
• What are the key differences between exothermic and endothermic reactions?

  • Exothermic reactions release energy, increasing surroundings' temperature.
  • Endothermic reactions absorb energy, decreasing surroundings' temperature.
• What are the key components of energy profile diagrams for reactions?

  • Reactants and products energy levels
  • Activation energy peak
  • Energy change during the reaction