Energy changes

Topics

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Sample objectives

What this unit covers

• Exothermic and endothermic reactions: Draw a simple reaction profile for an endothermic reaction.
• Exothermic and endothermic reactions: Use reaction profiles to identify whether a reaction is exothermic or endothermic.
• Exothermic and endothermic reactions: Explain that a reaction transferring energy to the surroundings leaves products with less energy than the reactants by the amount transferred.
• Exothermic and endothermic reactions: Evaluate uses and applications of exothermic and endothermic reactions from given information.
• Exothermic and endothermic reactions: (HT only) State that energy must be supplied to break bonds in reactants.
• Exothermic and endothermic reactions: (HT only) Explain that bond energies can be used to calculate energy needed to break bonds.
• Chemical cells and fuel cells (chemistry only): (chemistry only) Describe that cells contain chemicals that react to produce electricity.
• Chemical cells and fuel cells (chemistry only): (chemistry only) Describe batteries as two or more cells connected together in series.
• Chemical cells and fuel cells (chemistry only): (chemistry only) Explain why hydrogen fuel cells can be considered as an alternative to rechargeable cells and batteries.
• Chemical cells and fuel cells (chemistry only): (chemistry only) State that the overall reaction in a hydrogen fuel cell involves oxidation of hydrogen to produce water.