Bond Energies and Energy Changes

Bond Energies and Energy Changes

Learning Objective

At the end of the lesson you should be able to use bond energies to calculate energy changes for reactions

Introduce the learning objective and let the students know what they can expect to learn from the lesson.

What do you already know about bond energies?

What are Bond Energies?

Bond energy is the amount of energy required to break one mole of a specific bond in a gaseous molecule.

Explain what bond energies are and give a brief overview of how they work.

Types of Bond Energies

There are two types of bond energies: bond dissociation energies and bond formation energies.

Explain the two types of bond energies and give examples of each.

Calculating Energy Changes

The energy change for a reaction can be calculated using the bond energies of the reactants and products.

Explain how bond energies can be used to calculate energy changes for reactions.

Equation for Energy Change

ΔH = ΣBE(reactants) - ΣBE(products)

Show the equation for calculating energy changes using bond energies and explain each term.

Example Calculation

Calculate the energy change for the reaction: 2H2(g) + O2(g) → 2H2O(g)

Walk through an example calculation using the equation and explain each step.

Limitations of Bond Energies

Bond energies are averages and can vary depending on the specific molecule and conditions of the reaction.

Explain the limitations of using bond energies to calculate energy changes and give examples.

Applications of Bond Energies

Bond energies are important in many fields, including chemistry, physics, and biology.

Give examples of how bond energies are used in different fields and how they contribute to our understanding of energy changes in reactions.

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.