Energy Profile Diagrams: Understanding Chemical Reactions

Energy Profile Diagrams: Understanding Chemical Reactions

Learning Objective

At the end of the lesson you will be able to understand the concept of energy profile diagrams and how they relate to chemical reactions.

Introduce the learning objective to the students and explain what they will be able to do by the end of the lesson.

What do you already know about chemical reactions and energy?

What are Energy Profile Diagrams?

Energy Profile Diagrams show the energy changes that occur during a chemical reaction. They help us understand the energy required to break bonds and the energy released when new bonds are formed.

Explain what energy profile diagrams are and why they are important in understanding chemical reactions.

Activation Energy

Activation energy is the energy required to start a chemical reaction. It is the energy needed to break the bonds in the reactants before new bonds can form and products can be made.

Define activation energy and explain why it is important in chemical reactions.

Exothermic Reactions

Exothermic reactions release energy and have a negative ΔH value. The energy released is shown as a downward arrow on the energy profile diagram.

Explain what exothermic reactions are and how they are represented on energy profile diagrams.

Endothermic Reactions

Endothermic reactions absorb energy and have a positive ΔH value. The energy absorbed is shown as an upward arrow on the energy profile diagram.

Explain what endothermic reactions are and how they are represented on energy profile diagrams.

Reaction Progress

The x-axis of an energy profile diagram represents the reaction progress, with the reactants on the left and products on the right.

Explain what the x-axis of an energy profile diagram represents and where the reactants and products are located.

Catalysts

Catalysts lower the activation energy required for a reaction to occur. They are shown as a lower energy peak on the energy profile diagram.

Explain what catalysts are and how they are represented on energy profile diagrams.

Practice

Use the energy profile diagram provided to identify whether the reaction is exothermic or endothermic, and where the activation energy is located.

Provide a practice energy profile diagram for students to analyze and identify key components of the diagram.

Write down 3 things you learned in this lesson.

Have students enter three things they learned in this lesson. With this they can indicate their own learning efficiency of this lesson.

Write down 2 things you want to know more about.

Here, students enter two things they would like to know more about. This not only increases involvement, but also gives them more ownership.

Ask 1 question about something you haven't quite understood yet.

The students indicate here (in question form) with which part of the material they still have difficulty. For the teacher, this not only provides insight into the extent to which the students understand/master the material, but also a good starting point for the next lesson.