Insta-worms

Objectives

• Name some practical uses for polymers.

• Describe in general terms what occurs during a polymerization reaction.

• Investigate the properties of common polymers.

Materials

• Per Pair or small Group:
  powdered calcium chloride
  sodium alginate solution or Gaviscon®
  water
  cups
  squirt bottles for the sodium alginate solution
  plastic baggies for each student

  *Sodium alginate solution is available in pharmacies. An alternative is to use Gaviscon®, a heartburn remedy that has sodium alginate as a primary ingredient.

  Teachers’ Source and Steve Spangler Science  sell a complete ‘’worm kit’’.

Key Questions

• How was the “worm” created?
• Which chemical is polymerizing in this reaction?
• Does your worm look similar or different to your partners’? Explain.
• Could these chemicals be useful in creating any other sort of polymers?
• Where is the substance starch found? In what? What do we use starch for?

What To Do

Preparation:

1. Make the calcium chloride solution: For each group of students, start with ¾ of a cup of warm water into a cup. Add a teaspoon of calcium chloride powder and stir with a spoon until most of the powder dissolves.
2. Set up stations for each group of students. Make sure that each station has:

• Calcium chloride solution in a cup
• Sodium alginate solution in a squirt bottle
• Cups
• Plastic sandwich bags (one per student)

Instructions (You may want to do a demonstration first):

1. A small group (2–4) of students can share a cup of calcium chloride solution. Each student can make their own ‘’worm’’.
2. Squirt a small stream of the sodium alginate solution into the cup containing the calcium chloride solution.
3. Carefully pull the “worm” out of the calcium chloride solution with their hands. If the worm breaks, the gooey end can go back into the calcium chloride solution to seal it up.
4. Store the ‘’worm’’ in a sandwich bag.
5. Wash excess calcium chloride solution down the sink.

Extensions

• What happens if you use more or less calcium chloride powder when making the CaCl2 solution? Do your worms still form?
• Make colourful worms by adding food colouring to the sodium alginate.

Other Resources

University of Southern Mississippi | Polymer Science Learning Center | Make a Virtual Polymer