Making homemade playdoh isn't just a great sensory activity, it's also a fun way to introduce chemical reactions to your kids. During this activity, you can really ask your kids all sorts of questions about what is happening. Ask them what role they think each of the ingredients plays in the chemical reaction, what changes are happening after they add the water? 

Making the Playdoh

Ingredients

  • 2 cups flour
  • 1 cup salt (we used finely ground Himalayan salt, but any salt will work.)
  • 2 Tbsp cream of tartar
  • 2 Tbsp oil
  • Food coloring or liquid watercolors
  • 2 cups boiling water

Instructions

  1. Mix dry ingredients in a bowl.
  2. Make a well in the center and add oil and coloring.
  3. Pour in boiling water and mix.
  4. Mix really well with a spoon and then once the mixture is cool, knead it together with your hands.

Each component in playdoh has its own special role! Flour is the main component, the water causes the proteins in the flour to change shape and get more stretchy. The salt helps the proteins to hold their shape and stabilizes them. The cream of tartar is what gives playdoh its elasticity. And the oil helps to give the mixture moisture. Even adding food coloring to the oil while waiting for the water to boil is another excellent chance to talk about science. For example, did you notice that the food coloring did not mix with the oil? Why might that be? This is a perfect time to talk about polar and non-polar things as well. Just like water and oil do not mix, food coloring is polar and will mix with water, but will not mix with the oil. 

After the playdoh is mixed and ready, it can be shaped into a volcano for the next part of the lesson, where we investigate acid-base reactions.

Playdoh Volcano

Ingredients

  • Homemade playdoh (see above to make your own, or store bought can be used)
  • 2 Tbsp baking soda
  • 1/2 cup vinegar

Instructions

  1. Mold the playdoh into the shape of a volcano. When shaping the crater, you can play with different depths, however about halfway down is a good distance.
  2. Add the baking soda into the crater.
  3. Add the vinegar last, and step back and watch!

Baking soda is a base, and vinegar is an acid. During the reaction, when the baking soda is mixed with vinegar, the baking soda (base) takes a proton from the vinegar (acid) and the reaction causes baking soda to transform into water and carbon dioxide. That's why it bubbles!