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5. Energy changes

Exothermic and endothermic reactions

4 lessons
5.1 Exothermic and endothermic reactions What exothermic and endothermic reactions are, how they change the temperature of the surroundings, everyday examples and uses of each, and how energy is conserved in reactions. AQA Edexcel OCR 5.2 Required practical: temperature changes How to investigate the temperature change in a reaction using a polystyrene cup, how the volume of alkali added affects the highest temperature in a neutralisation, and how to reduce energy losses. AQA Edexcel OCR 5.3 Reaction profiles and activation energy How to draw and interpret reaction profiles for exothermic and endothermic reactions, what activation energy is, and why breaking bonds is endothermic and making bonds is exothermic. AQA Edexcel OCR 5.4 Bond energy calculations How to use bond energies to calculate the overall energy change of a reaction, why the answer is negative for exothermic reactions and positive for endothermic reactions, and worked examples. Higher only AQA Edexcel OCR

Chemical cells and fuel cells

2 lessons
5.5 Chemical cells and batteries How a simple chemical cell produces a voltage from two different metals in an electrolyte, the factors affecting the voltage, how batteries are made, and the difference between non-rechargeable and rechargeable cells. Separate only AQA Edexcel OCR 5.6 Hydrogen fuel cells How a hydrogen fuel cell uses the oxidation of hydrogen to produce a voltage, its half equations, and the advantages and disadvantages of hydrogen fuel cells compared with rechargeable batteries. Separate only AQA Edexcel OCR