Exothermic and endothermic chemical reactions
Lesson details
Learning outcome
I can identify whether a chemical reaction is exothermic or endothermic and explain how I know.
Key learning points
- An exothermic chemical reaction causes an increase in temperature (of the surroundings).
- An endothermic chemical reaction causes a decrease in temperature (of the surroundings).
- An exothermic reaction transfers energy from the reactants to the surroundings.
- An endothermic reaction transfers energy from the surroundings to the products.
Keywords
Exothermic chemical reaction - is a type of reaction in which energy is transferred from the reactants to the surroundings, e.g. combustion.
Endothermic chemical reaction - is a type of reaction in which energy from the surroundings is transferred to the products, e.g. photosynthesis.
Dissipate - Thermal energy can dissipate which means it can be transferred to the environment and wasted.
Common misconception
The difference between the surroundings (where the reaction takes place, e.g. solution) and the environment (where the reaction mixture is, e.g. classroom). The existence of cold.
Use the separate terms of surroundings and environment throughout the lesson. Explain that thermal energy transfer only takes place from somewhere that is warmer and somewhere that is cooler.
Teacher tip
Demonstrate the classic endothermic reaction between solid hydrated barium hydroxide and solid ammonium chloride, ensure this is practiced and risk assessed prior to the lesson.
Content guidance
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 terms to their definitions.
Q2.True or false? A change of state indicates that a chemical reaction has taken place.
Q3.Which of the following are examples of chemical reactions?
Q4.Hydrogen gas and magnesium chloride are formed when magnesium reacts with hydrochloric acid.
Which of the following represents the chemical equation for the reaction?
Q5.Burning is an example of ...
Select two correct answers.
Q6.Calculate the mass of carbon dioxide formed when 13.5 g of calcium carbonate reacts to form 7.6 g of calcium oxide.
calcium carbonate → calcium oxide + carbon dioxide
Assessment exit quiz
6 Questions
Q1.Match the following terms to their definitions.
Q2.Endothermic reactions cause ...
Q3.Which of the following are reactions that are usually exothermic?
Q4.The method for finding the lowest temperature of a reaction has been mixed up.
Starting with measuring the volume of solution, sort the following steps into the correct order.
Q5.A pupil monitored the temperature of a reaction. The start temperature was 20°C and the end temperature 15°C.
Which of the following statements about the reaction are correct?
Q6.True or false? After an exothermic reaction, the products of the reaction contain more energy than the reactants.
To help you plan your 8 science lesson on: Exothermic and endothermic chemical reactions, download all teaching resources for free and adapt to suit your pupils' needs...
To help you plan your 8 science lesson on: Exothermic and endothermic chemical 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.
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