HOW TO: pH paper from a Poinsetta

PLEASE NOTE: PARENTAL HELP IS A MUST ON THIS PROJECT

Poinsettia
Creative Commons License photo credit: Southernpixel

Materials:
Parental help
Red petals from a poinsettia plant
Blender
Microwave
Coffee filters
Microwave safe dish
Baking soda mixed with water (test substance)
Vinegar (test substance)
Strainer
Straw or medicine dropper

What to do:

1. Grab your parents to help you.
2. Put the red parts of the poinsettia in a blender with a small amount of water and blend.
3. Transfer this mixture to a microwave safe dish and microwave with water (enough to cover the plant material) for about 1 minute and let steep like tea.
4. Strain the mixture and throw away the plant matter and reserve the liquid.

| Poinsettia  |
Creative Commons License photo credit: arquera

5. Soak several coffee filters in this mixture until they are colored. Allow them to dry.
6. Cut them into strips.
7. Use a medicine dropper or straw to apply different solutions such as vinegar or the baking soda solution to the paper. What happens?
8. What color does it turn when it is exposed to an acid (vinegar)?
9. What color does it turn when it is exposed to a base (baking soda solution)?
10. Can you find other acids or bases in your house?

What’s going on here?
Many different plants have pigments that are very sensitive to changes in acidity. The poinsettia is one example and red cabbage is another. When acids or bases come into contact with the paper dyed with the plant extract, a wonderful color change occurs!

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