AS Level Chemistry - Unit 5.1 Enthalpy change, ΔH

**This Powerpoint specifically uses the Cambridge AS Level Chemistry Syllabus (9701) and covers all criteria for – Unit 5.1 Enthalpy change, ΔH
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Students will be able to -

1 understand that chemical reactions are accompanied by enthalpy changes and these changes can be exothermic (ΔH is negative) or endothermic (ΔH is positive)

2 construct and interpret a reaction pathway diagram, in terms of the enthalpy change of the reaction and of the activation energy

3 define and use the terms:
(a) standard conditions (this syllabus assumes that these are 298K and 101kPa) shown by ⦵.
(b) enthalpy change with particular reference to: reaction, ΔHr, formation, ΔHf, combustion, ΔHc, neutralisation, ΔHneut

4 understand that energy transfers occur during chemical reactions because of the breaking and making of chemical bonds

5 use bond energies (ΔH positive, i.e. bond breaking) to calculate enthalpy change of reaction, ΔHr

6 understand that some bond energies are exact and some bond energies are averages

7 calculate enthalpy changes from appropriate experimental results, including the use of the relationships
q = mcΔT and ΔH = –mcΔT/n

**Every Powerpoint includes learning objectives, a starter and plenary, suitable activities and review questions with mark scheme. We also provide a free pdf version of the file so it can easily be printed for students as a handout or uploaded to the school VLE system.
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