Describe How Chemical Reactions Can Release Energy

Learning objectives
iAppreciate that chemical reactions, including combustion and displacement, can release energy, including voltaic cells. (red only)
iiUnderstand combustion reactions of various fuels.
Scientific enquiry
iiiMake measurements of temperature.
ivUse information from secondary sources to draw conclusions. (Framework YTO Sc1 8d)
Suggested alternative starter activities (5–10 minutes)
Recap last lesson / Share learning objectives / Problem solving / Capture interest (1) / Capture interest (2)
Pupils match jobs to definitions/descriptions. /

Describe how chemical reactions can release energy.

Make measurements of temperature. (Sc1)

/ Pupils work in groups to answer the question 'What evidence do we have that some chemical reactions release heat?' / Demo of lighting a match. / Demo of a voltaic cell showing voltage and lamp lit.
Suggested alternative main activities
Activity / Learning objectives see above / Description / Approx.
timing / Target group
C / H / E / S
Textbook H2 / i and ii / Teacher-led explanation and questioning OR Pupils work individually, in pairs or in small groups through the in-text questions and then onto the end-of-spread questions if time allows. / 20 min / R/G / G / R / S
Activity H2a
Practical / i, ii and iii / Measuring energy change Pupils measure the energy changes for some metal displacement reactions. / 30 min /  / 
Activity H2b
Discussion / i and iv / The right fuel for the job Pupils look at different scenarios in which a fuel is used and decide what fuel is best for the job. / 20 min / 
Suggested alternative plenary activities (5–10 minutes)
Review learning / Sharing responses / Group feedback / Word game / Looking ahead
Pupils write a definition of the word 'fuel'. Individuals read out their definitions to the class. / Pupils report results of Activity H2a to the class. Results are summarised on the board and discussed. / Pupils work in groups using information from Activity H2b to produce an advertising poster for a fuel, designed to appeal to those who might purchase the fuel. / Pupils use cards to construct word equations for the reactions in Activity H2a. / Demo adding barium nitrate solution a little at a time to sodium sulphate solution, each time getting more precipitate. Ask pupils 'Could we go on doing this forever?'
Learning outcomes
Most pupils will … / Some pupils, making less progress will … / Some pupils, making more progress will …

know the basic fuel reactions and be able to write word equations for them

have some understanding of the relative advantages/disadvantages of different fuels.

appreciate that chemistry is used to provide much of our energy.

be able to write balanced chemical equations for the key reactions

know that electrical energy can be produced from a voltaic cell.

Key words / Out-of-lesson learning
None / Homework H2
Textbook H2 end-of-spread questions

This worksheet may have been altered from the original on the CD-ROM.