In this lesson plan, adaptable for grades 5-12, students use an interactive simulation called Concentration to explore the concentration of different solutes and solvents. This simulation covers several related topics, such as molarity, saturation, precipitation, evaporation, and some basic stoichiometry.

### Students will:

1. Explore how volume of solution and amount of solute relate to its concentration.
2. Discover what happens to solutions at the point of saturation.
3. Understand that different solutes have different saturation points.
4. Learn how to figure out the mass of the solute in the solution by using the concentration of the solution.

### Materials:

• Computers or other devices with Internet access
• Interactive whiteboard
• Periodic table of the elements

### Preparation:

This lesson features an interactive simulation titled Concentration, developed by our award-winning partner PhET through the University of Colorado Boulder.  The simulation invites students to explore various solution properties related to solubility concentration.

Watch the Concentration video primer for an introduction to the Concentration simulation’s features and uses. Then review the Concentration Simulation Overview to learn about the sim controls and model simplifications.

Preview and play with the Concentration sim to plan how you will adapt it to your students’ needs.

Students may explore the sim individually or with a partner.

Build background knowledge or reinforce topics with these BrainPOP movies: Compounds & Mixtures, Moles, Salt, and Water.

### Lesson Procedure:

1. Have students open up the Concentration sim and explore the various interactions that they can do within the sim.
2. After everyone has had a chance to explore the sim, encourage students to some features they discovered. Examples: add water, remove solvent, evaporate water, change solute, etc. Ask some priming questions here to promote critical thinking. For example, What’s the difference between evaporating and draining the solvent?
3. Based on what they’ve seen so far, ask  students to predict the relationship between the volume of solution, the amount of solute, and the concentration. For students who have taken algebra I, challenge them to predict a mathematical equation to model the relationship.
4. Play the BrainPOP movie Moles on a whiteboard or other display. Pay special attention to time 3:05 to end of video. Explain to students that they will use moles to calculate the mass of the amount of solute that they put into the solution.
5. Instruct students to pick a solute that has a chemical formula (i.e. not Drink Mix). After adding the solute to the water, have students calculate the amount of solute they added in grams. (You may need to guide younger students, but suggest that they refer to the BrainPOP movie Moles as a hint. They will need to use the periodic table and calculate the molar mass of the solute they added first.)
6. Challenge your students to create a “saturated” solution.
7. Have students share what makes a “saturated” solution special and how they created it (only two ways: evaporation or adding more solute). Advanced students can reflect on why draining the solvent will never cause a solution to be saturated.
8. Have your students share what they think it means for a solution to be “saturated.” If they’re having trouble, prime them on what they observed, especially the concentration level as a solution moves from a non-saturated state to a saturated state. What did they notice about the saturation points of different solutes?
Filed as:  3-5, 6-8, 9-12, Concentration