Unit 5 - Energy Changes PDF

**Topic** **Unit 5 - Energy changes** **R** **A** **G** --------------------------------------...

**Topic** **Unit 5 - Energy changes** **R** **A** **G** ------------------------------------------------ -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- ------- ------- ------- **4.5.1 Exothermic and endothermic reactions** Describe how energy is transferred to or from the surroundings during a chemical reaction       Explain exothermic and endothermic reactions on the basis of the temperature change of the surroundings and give examples of everyday uses       ***Required practical 4**: investigate the variables that affect temperature changes in reacting solutions*       Describe what the collision theory is and define the term activation energy       Interpret and draw reaction profiles of exothermic and endothermic reactions, inc identifying the relative energies of reactants and products, activation energy and overall energy change       **HT ONLY: Explain the energy changes in breaking and making bonds and calculate the overall energy change using bond energies**       **4.5.2 Chemical cells and fuel cells** *[Chem ONLY] : Describe what a simple cell and a battery is and how they produce electricity*       *[Chem ONLY] : Describe why alkaline batteries are non-rechargeable, state why some cells are rechargeable and evaluate the use of cells*       *[Chem ONLY] : Describe fuel cells and compare fuel cells to rechargeable cells and batteries*       *[Chem ONLY] : Describe the overall reaction in a hydrogen fuel cell*       *[Chem ONLY] : Write half equations for the electrode reactions in a hydrogen fuel cell*