Energy changes in reactions
Lesson details
Learning outcome
I can complete a series of practicals to measure the temperature change and record appropriate results, concluding whether the reactions were exothermic or endothermic.
Key learning points
- Changes in heat energy accompany salts dissolving in water.
- Changes in heat energy accompany neutralisation, displacement and precipitation reactions.
- Exothermic and endothermic reactions have everyday uses.
- When reactions take place in solution, temperature changes can be measured to reflect the energy changes.
Keywords
Exothermic - An exothermic chemical reaction is a type of reaction in which energy is transferred from the reactants to the surroundings e.g. combustion.
Endothermic - An endothermic chemical reaction is a type of reaction in which energy is transferred from the surroundings to the products e.g. photosynthesis.
Solution - A solution is formed when a substance dissolves into a liquid.
Calorimetry - Calorimetry is an experiment than can be used to measure an energy change during a reaction.
Common misconception
Pupils struggle to identify the surroundings in exothermic and endothermic reactions and why the temperature decreases in endothermic reactions when energy is transferred into the reaction.
Explain that the surroundings are where you are making the temperature measurements and that the energy is transferred from the thermal energy store of the surroundings to the chemical energy store of the reaction.
Teacher tip
Get the pupils to experimentally identify different exothermic and endothermic reactions and then explain why they are seeing a temperature change, identifying the surroundings in each case.
Equipment
Beakers, polystyrene coffee cups and lids, thermometers or temperature probes, stirring rods.
Content guidance
Risk assessment required - chemicals
Risk assessment required - equipment
Supervision
Adult supervision required
Licence
Lesson video
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Prior knowledge starter quiz
6 Questions
Q1.Match the following state symbols to the correct meaning.
aqueous
solid
liquid
gas
Q2.Which of the following statements about exothermic reactions are true?
Q3.What is the SI unit for energy?
Q4.Which statement about energy is correct?
Q5.The hotter an object, the more energy is present in its store of energy.
Q6.Which of the following methods of energy transfer involves only the vibration of particles?
Assessment exit quiz
6 Questions
Q1.Match the following terms to the correct definition.
Chemical reaction in which energy is transferred to the surroundings.
Chemical reaction in which energy is transferred to the products.
Formed when a substance dissolves in a liquid.
An experiment used to measure energy change during a reaction.
Q2.Which of the following are examples of exothermic chemical reactions?
Q3.After an endothermic reaction, the temperature of the surroundings .
Q4.Which of the following are examples of everyday uses of exothermic reactions?
Q5.Barium sulphate, BaSO₄, is a precipitate produced during a chemical reaction. Which state symbols should appear after BaSO₄ in the symbol equation?
Q6.A student measured the initial temperature of a reaction as 22°C and the final temperature as 16°C. Which of these statements about the reaction are true?
To help you plan your 10 combined science lesson on: Energy changes in reactions, download all teaching resources for free and adapt to suit your pupils' needs...
To help you plan your 10 combined science lesson on: Energy changes in reactions, download all teaching resources for free and adapt to suit your pupils' needs.
The starter quiz will activate and check your pupils' prior knowledge, with versions available both with and without answers in PDF format.
We use learning cycles to break down learning into key concepts or ideas linked to the learning outcome. Each learning cycle features explanations with checks for understanding and practice tasks with feedback. All of this is found in our slide decks, ready for you to download and edit. The practice tasks are also available as printable worksheets and some lessons have additional materials with extra material you might need for teaching the lesson.
The assessment exit quiz will test your pupils' understanding of the key learning points.
Our video is a tool for planning, showing how other teachers might teach the lesson, offering helpful tips, modelled explanations and inspiration for your own delivery in the classroom. Plus, you can set it as homework or revision for pupils and keep their learning on track by sharing an online pupil version of this lesson.
Explore more key stage 4 combined science lessons from the Energy changes in reactions unit, dive into the full secondary combined science curriculum, or learn more about lesson planning.