exothermic and endothermic reactions

• in a chemical reaction mass is always...

  mass is always conserved
• endothermic reaction


  a reaction where energy required to break bonds is more than energy released in bond making

  - energy is absorbed

  - thermal energy is converted to chemical potential

  - temperature decreases
• endothermic reaction profile

  
• exothermic reaction


  a reaction where energy required to break bonds is less than energy released by making bonds

  - energy is released

  - chemical potential is converted to thermal energy

  - temperature increases
• exothermic reaction profile

  
• activation energy is...


  the minimum amount of energy required to start a chemical reaction
• to break bonds...


  energy must be supplied
• bond making is an ... process

  exothermic (releases energy)
• bond breaking is an ... process

  endothermic (requires energy)
• if the overall change in energy is negative...

  the chemical reaction is exothermic
• if the overall change in energy is positive...

  the chemical reaction is endothermic