Energy changes

• Endothermic reactions include thermal decompositions, and the reaction of citric acid and sodium hydrogencarbonate.
• Exothermic reactions include combustion, oxidation reactions and neutralisation.
• Minimum amount of energy that particles must have to react is called the activation energy.
• In fuel cells, the fuel is oxidised electrochemically to produce a potential difference.
• The overall reaction in a hydrogen fuel cells involves the oxidation of hydrogen to produce water.
• Alkaline batteries are non-rechargeable
• In fuel cells the anode is negative and the cathode is positive
• Electrodes in fuel cells are made from porous carbon.