3. Lesson 3: Energy Transfer When Bonds Break

Carole Namowicz, Shruti Researcher
Chemistry
100 min
High School
v5
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Overview

In this lesson, students will utilize a simulation that shows the dissolving of an ionic compound in water. Water molecules must collide with the ionic compound in the proper orientation and with enough kinetic energy for the ionic compound to separate into constituent cations and anions.

The activity will force students to equate the reduction in the temperature of the water with the breaking of the ionic bond. The kinetic energy of the water is transferred to break the ionic bonds. This is an endothermic process. Students will only be able to recognize this when they view the simulation with a smaller number of water molecules present (~10).

After students develop the understanding that breaking bonds is an endothermic process, they will be asked to model bonds breaking by showing the changes in KE and PE of the system (ionic compound) and the surroundings (water).

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Underlying Pages

Standards

Next Generation Science Standards
  •   Physical Science
    • [HS-PS1-4] Develop a model to illustrate that the release or absorption of energy from a chemical reaction system depends upon the changes in total bond energy.
    • [HS-PS3-2] Develop and use models to illustrate that energy at the macroscopic scale can be accounted for as a combination of energy associated with the motions of particles (objects) and energy associated with the relative positions of particles (objects)
Computational Thinking in STEM
  •   Data Practices
    • Collecting Data
    • Creating Data
    • Manipulating Data
    • Visualizing Data
    • Analyzing Data
  •   Modeling and Simulation Practices
    • Assessing Computational Models
    • Using Computational Models to Understand a Concept
  •   Systems Thinking Practices
    • Communicating Information about a System
    • Investigating a Complex System as a Whole
    • Thinking in Levels
    • Understanding the Relationships within a System
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