Why is the Great Salt Lake salty?

• Teach students about why the Great Salt Lake is salty by using a model of the rivers that flow into the Great Salt Lake.
• This lesson takes from 35 to 45 minutes and is intended for 7th and 8th graders.

Goal/Objective

Students will understand and be able to explain why the Great Salt Lake is salty.

Materials

• Salt to be dissolved in water.
• Tap Water.
• 3 Beakers.
  • X2 250mL
  • X1 800mL
• Funnel
• Bunsen burner
• A small model which represents the flow of salt and water.
  • The model will include three sections (boxes help in making levels)
    • Top has a path (Pipe/Clay) which will represent a river.
    • Middle, one beaker to represent a lake, and also another river path.
    • Bottom, one beaker to represent the Great Salt Lake.

Process

This is a discussion type lesson with an experiment to start it off.

Experiment

• This experiment should take some time so start it before the discussion.
• Start by dissolving the salt into your tap water.
• You’ll pour the water into the top of your model and show how the water goes from the Provo River to Utah Lake through the Jordan River to the GSL.
• Once you’ve filled the GSL beaker to approximately 100ml and then put it over the Bunsen burner to evaporate the water. (This will take a long time.)
• At the end of the discussion show how the GSL beaker is saltier than the Utah Lake beaker. (You probably won’t evaporate all the water but when compared you’ll see how one beaker is more opaque than the other because of salt.)

Discussion

• Explain that you’ll learn the answer to the question, “Why is the GSL Salty?”.
• Take some hypotheses from the students and write them on the board.
• Using a projection of the rivers and lakes in the GSL area, explain the reason why it truly is salty.
• Answer all questions to the best of your knowledge. And you can also guide the discussion by asking your own questions.
• You can teach with the vocabulary words and explain how they are relevant.
• At the end of discussion you’ll explain the experiment and how it represents the GSL.

Vocabulary

• Saleen
• Soluble
• Terminal
• Closed basin
• Sublimation/Evaporation/Deposition

How will you determine you were successful?

• Lessons can end with an oral quiz, survey, or small worksheet.
  • Remember that the quiz or worksheet is for you to determine how well you did in teaching them, not how much the students know.
• Quiz might include a series of questions that lead up to the explanation of why the Great Salt Lake is salty.
  • Perhaps include some vocabulary.
  • Explain how the salt gets to the Great Salt Lake.
  • Explain why the salt doesn’t leave the Great Salt Lake