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Secret Goldenrod Messages


Source Institutions

    American Chemical Society

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Secret Goldenrod Messages

In this activity, learners write invisible messages on goldenrod paper, and make the message appear and disappear using acids and bases. Goldenrod paper is paper that has been dyed with natural goldenrod pigment. The pigment is a natural indicator that changes from gold to red when exposed to bases (such as laundry detergent, baking soda), and back to gold when exposed to an acid (such as vinegar). The secret message is written with wax, which protects the surface of the paper from the applied solutions.

Quick Guide


Preparation Time:
5 to 10 minutes

Learning Time:
30 to 45 minutes

Estimated Materials Cost:
1 cent - $1 per student

Age Range:
Ages 6 - 14

Resource Type:
Activity

Language:
English, Spanish

Materials List (per student)


  • Measuring spoons
  • Powdered laundry detergent
  • 4 Plastic cups
  • Pencil or pen
  • Masking tape
  • Baking soda
  • Water
  • Vinegar
  • Goldenrod paper
  • Piece of white candle or crayon
  • Cotton swabs or paintbrushes

Subjects


  • Physical Sciences
    • Chemistry
      • Acids and Bases
      • Solutions
  • The Nature of Science
    • The Scientific Process
      • Conducting Investigations

Informal Categories


  • Crime Science

Audience


To use this activity, learners need to:

  • see
  • see color
  • touch

Learning styles supported:

  • Links STEM to other topics of interest such as arts and humanities
  • Involves hands-on or lab activities

Other


Access Rights:

  • Free access

By:

Rights:

  • All Rights Reserved, American Chemical Society, ©2008

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