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Course: High school chemistry > Unit 3

Lesson 3: Energy of chemical reactions
Science
High school chemistry
Chemical reactions
Energy of chemical reactions
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Problem

The following diagram represents a chemical reaction (the reaction system) and the surrounding environment.
A blue box represents the system where the reaction occurs; everything outside of this box is the surroundings. A large orange arrow points into the box to show lots of energy going in to the system from the surroundings. A small green arrow points outside of the box to show a little bit of energy leaving the system to go to the surroundings. Inside the blue box is a potential energy graph. The energy of the products is 240kJ higher than the energy of the reactants.
Use the diagram to complete the statements.
  • The diagram shows that the energy required to break the bonds in the reactants is
    than the energy released during the formation of products.
  • The diagram represents an
    reaction.
  • The diagram shows that, overall, 240 kJ of energy is transferred
    the surroundings. This will result in the surroundings becoming
    .