Endothermic and Exothermic

• Exothermic reactions transfer energy from the reacting molecules to the surroundings and the surroundings get hotter
• Examples of exothermic reactions (scientific)

  • combustion
  • neutralisation
• Exothermic reaction profile


  In an exothermic reaction the energy of the products is less than the energy of the reactant. This is because energy is transferred from the reaction to the surroundings. The difference between the energy of the products and the energy of the reactants tells us how much energy has been released into the surroundings.

  
• Exothermic reaction examples ( non scientific)

  • Hand warmers
  • self heating cans
• Endothermic reactions take in energy from surroundings and the temperature of the surroundings decrease
• Example of endothermic reaction ( scientific)

  Thermal decomposition
• endothermic reaction profile


  In an endothermic reaction the products have more energy than the reactants. This is because energy has been taken in from the surroundings. The difference between the energy of the reactants and the energy of the products tells us how much energy has been taken in by the reaction.

  
• Activation energy 


  The minimum amount of energy particles must have to react is called activation energy
• On an energy profile diagram the activation energy is from the reactants to the peak of the curve