We’ve been doing a lot of kitchen-based chemistry lately. First, we baked these cookies. My primary motivation in making these was to have cookies to eat, but we also talked about solids and liquids, and how different liquids turn to solids at different temperatures (water vs. butter) and looked at how the texture of the dough changed as we added sugar, then flour, then oatmeal, and finally chocolate chips.
We added food coloring drops to a pan of water and watched them disperse (see this post for a more thorough food coloring and water experiment).
Then I took the same pan of water, gave Emma white vinegar in a cup with a syringe and Johnny baking soda in a cup with a 1/4 teaspoon measuring spoon and had them play around with this acid-base combination (thank you Nicole from Tired, Need Sleep for providing this idea).
Next, we put white vinegar in the pan (with green food coloring, just for fun) and added baking soda for much more dramatic fizzing.
We finished off our kitchen chemistry by making a second batch of play dough (pink this time). We looked at how, when we added food coloring to water and oil, some of the food coloring got caught in the oil and so didn’t disperse as quickly.
Then we stirred it all up. We talked about how there were still a couple of beads of food coloring in oil that hadn’t gotten mixed in, and about how the big bubble of oil broke up into a bunch of little bubbles but didn’t mix perfectly with the water.
Finally, we baked the play dough. We talked about how the red water/oil mixture turned pink when we mixed it with the white flour, salt, and cream of tartar. We talked about how we put in flour to make the water thick, salt to keep it from sticking to everything, oil to make it feel less grainy from the salt, and cream of tartar to make it more stretchy. And, of course, food coloring to make a fun color. And we all enjoyed watching the mixture change quickly from soup-like to dough-like.
Do you know of any other fun kitchen chemistry activities we can try?