Science

Exploring Solubility

Global 40 minutes
Objectives: 
  • I will learn about the Scientific Method and how it can be applied to the solubility experiment. 
  • I will be able to define the terms Soluble and Insoluble and identify which of the materials used in the experiment were soluble in water and which were insoluble in water. 

Materials:
  • Clear Plastic Cups 
  • Beakers for Materials 
  • Goggles 
  • Plastic Spoons 
  • Popsicle Sticks 
  • Sugar 
  • Salt 
  • Seltzer Water 
  • Food Coloring 
  • Baking Powder 
  • Oil 
  • Sand 
  • Flour 
  • Markers 
  • Pencils 
  • Bucket for Water 

Vocabulary/key terms:
Soluble
Insoluble
Scientific Method

Essential Questions:
What substances are predictably soluble in water?
How can we test our hypothesis?

Procedure:
Introduction of Activity 
  1. Write “Solubility” on the board and ask the students if they know what solubility means.
  2. Encourage all students to participate and take a guess and write their prediction under solubility on the board, or let them write it. 
  3. Define solubility as the ability for a substance to dissolve in another substance and explain that you are going to test the solubility of substances in water today. 

 Explanation of Scientific Method: 
  • Explain that every experiment that scientists run follows the same set of general steps called the scientific method. 
  • Since the kids are all scientists this week, they will follow the scientific method also.
  • Each slide has a few words about each step in the scientific method. As you discuss each step, relate it to the activity and have the students follow along on the worksheet.

Step 1: Ask a Question
  • Which of the substances dissolve in water?

Step 2: Learn and Observe
  • Have the students discuss their current knowledge of the topic that will help them make a hypothesis. Encourage them to think about experiences like swimming in the ocean, salt and sand, or cooking.

Step 3: Hypothesis
  • Have all the students make a prediction and record it on their worksheet.

Step 4: Test the Hypothesis
  • Break the students up into small groups to take part in the tests of each substance’s solubility.
  • Each group of 2 to 3 students will have a set of labeled cups and a Popsicle stick to stir in the water. 
  • Students will put a spoonful of each substance into the appropriately labeled cup then student volunteers will come around to each group and pour water into the cup at roughly the same amount, you can use a marked cup to measure how much water to add.

Step 5: Analyze the Results
  • Have all the students report their findings and discuss the results.
  • Teach the students that water is a very unique molecule and it can dissolve many substances, as it is the Universal Solvent.
  • This is very important for all living things.
  • For example, water dissolves important nutrients that allow creatures to live and grow.

Step 6: Share Your Results
  • Encourage students to share what they learned with their parents.