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Animation Activity: Net Ionic Equations Mark as Favorite (1 Favorite)

ACTIVITY in Solubility, Precipitate, Net Ionic Equation, Balancing Equations, Solubility Rules. Last updated November 16, 2022.


Summary

In this activity, students will use an animation to visualize what happens in a precipitate reaction on the particulate level, and they will see why writing a net ionic equation accurately represents what happens in these scenarios. The animation includes an example of diluting a soluble solid, mixing two aqueous reactants that yield aqueous products, and mixing two aqueous reactants that yield a precipitate.

Grade Level

High School

NGSS Alignment

This activity will help prepare your students to meet the performance expectations in the following standards:

  • HS-PS1-2: Construct and revise an explanation for the outcome of a simple chemical reaction based on the outermost electron states of atoms, trends in the periodic table, and knowledge of the patterns of chemical properties.
  • Scientific and Engineering Practices:
    • Developing and Using Models

Objectives

By the end of this activity, students should be able to:

  • Write complete and net ionic equations.
  • Identify spectator ions in a reaction.

Chemistry Topics

This activity supports students’ understanding of:

  • Net ionic equations
  • Balancing equations
  • Precipitates
  • Solubility

Time

Teacher Preparation: minimal
Lesson: 10-30 minutes

Materials

Safety

  • No specific safety precautions need to be observed for this activity.

Teacher Notes

  • All of the animations that make up the AACT Animation collection are designed for teachers to incorporate into their classroom lessons. Intentionally, these animations do not have any spoken explanations so that a teacher can speak while the animation is playing and stop the animation as needed to instruct.
  • If you assign this to students outside of class time, you can create a Student Pass that will allow students to view the animation (or any other video or ChemMatters article on the AACT website).
  • This animation would be most helpful to introduce the concept of net ionic equations after students have learned about balancing equations, solubility rules, and precipitate (double replacement) reactions.
  • The first visuals show water being added to AlCl3 (s), and when the particulate view is shown, there are H2O, Al3+and Cl- particles in the test tube. This would be a good place to reinforce or introduce the terms “dissolution,” “dissolving,” and/or “dissociation,” etc. to describe the particles of the soluble ionic compound separating when they are added to water. Then more water is added to the test tube, at which point you can reinforce/introduce the terms “dilution,” “concentration,” “solute,” “solvent,” etc. to describe the relationship between substances involved (AlCl3, the solute, and H2O, the solvent).
  • The next set of compounds are NaCl (aq) and K2SO4 (aq). You could pause the animation around 0:21 and have students predict what the products would be, write a balanced equation, and then determine whether a reaction will actually take place. All of this will appear on the screen. Then it will be shown at a particle level and students will see that the ions mix, but nothing really happens because there are no insoluble compounds that form from that combination of ions. This will then be shown as a complete ionic equation, and then as a net ionic equation where all the ions cancel out to reinforce the idea that no net reaction occurs.
  • The final set of compounds is MgCl2 (aq) and K2CO3 (aq). Like the previous example, you could pause the animation around 1:08 to have students predict products, balance the equation, etc. before it is shown on the screen. In this case, a solid precipitate, MgCO3 (s), forms and a reaction does occur. The complete and net ionic equations are then shown on screen.
  • We suggest that a teacher pause this animation at several points or watch it more than once to give students the opportunity to make notes, ask questions, and test their understanding of the concepts presented. The animation is about two minutes long and moves quickly, so students will likely require pausing or multiple viewings to successfully complete the student activity sheet if you choose to use it. Here are some of the points at which you might want to pause the video to allow students to answer the questions on the activity sheet:
  • Question 1 – 0:12
  • Question 2 – 0:15
  • Question 3 – 0:21
  • Question 4 – 0:41
  • Question 5 - 0:50
  • Question 6 – 1:00
  • Question 7 – 1:08
  • Question 8 – 1:33
  • Question 9 – 1:36
  • Question 10 - 1:46

For the Student

Lesson

As you view the animation, answer the questions below.

  1. The first set of test tubes contain liquid water and solid AlCl3. What happens on the particle level when they are mixed together?

  2. When the formulas reappear on the screen, the test tube containing AlCl3 is labeled as “AlCl3 (aq)” instead of “AlCl3 (s).” Why do you think this is – what do “(s)” and “(aq)” mean?

  3. Write the full, balanced molecular equation that would describe a reaction if it occurred between NaCl (aq) and K2SO4 (aq). Include state symbols.

  4. What happens when the NaCl (aq) and K2SO4 (aq) are mixed in the same test tube? Does a reaction occur?

  5. Write the complete ionic equation describing what occurs when the contents of these test tubes are mixed.

  6. Write the net ionic equation for this process. Does this make sense based on what you saw on the particle level in the test tubes?

  7. Write the full, balanced molecular equation that would describe a reaction if it occurred between MgCl2 (aq) and K2CO3 (aq). Include state symbols.

  8. What happens when the MgCl2 (aq) and K2CO3 (aq) are mixed in the same test tube? Does a reaction occur?

  9. Write the complete ionic equation describing what occurs when the contents of these test tubes are mixed.

  10. Write the net ionic equation for this process. Does this make sense based on what you saw on the particle level in the test tubes?

Conclusion

  1. In the final example of the animation, the reaction between MgCl2 (aq) and K2CO3 (aq), the ions K+ (aq) and Cl (aq) are examples of “spectator ions.” Think of what a “spectator” is in everyday life (ex: at a musical performance, or a sporting event) and explain why these ions are referred to this way.
  2. Write the balanced molecular equation, complete ionic equation, and net ionic equation for the reaction that occurs between CaCl2 (aq) and K3PO4 (aq). Circle any spectator ions in the complete ionic equation. (Review your solubility rules if you need help predicting the products!)