Bubbling Blobs
Summary
In this chemistry lab, students investigate how oil and water don't mix. They will work on their observation skills and their ability to follow directions to ensure they get the correct results. Students can then develop a new, testable question related to water mixing with other liquids.
CollapseLearning Goals
This activity is designed for students to observe how oil and water do not mix. The students will discuss why they think the water and oil don't mix and why the tub tint reacts with the water. They should also notice that the tub tints do not mix with the oil. The terms soluble and density are key to this lab.
Context for Use
Bubbling Blobs could be used with any elementary grade level. The size of class would depend on how many supplies you have. It is best that each students make his/her own. This activity could be done in a variety of settings. It wouldn't have to necessarily be in a classroom, could also be done in a day care or after school program. This is a lab project. This activity could take up to 30 minutes, depending on how in depth your discussion gets. For this project you need one clean, plastic baby soda bottle for each student, soda bottle cap, vegetable oil(the cheaper the better), tub tints, water, and dropper. The students should have had the steps for the activity explained to them before they start and then try and do each step as a class.
Description and Teaching Materials
You should have the baby soda bottles filled almost to the top with vegetable oil for the students. Then have the students tell what they already know about oil and water. Tell them that they are going to observe what happens when the two mix. Have the studens add 1-2 tub tints. Notice that the tubtints dont react in the oil. Fill the rest of the bottle with water (almost to the top but not overflowing). Watch what happens. When the bubbling stops, place the cap on top. Its just like a lava lamp! Tip the bottle back and forth and watch the waver appear. The tiny droplets of liquid join together to make one big lava-like blob.
Teaching Notes and Tips
When you poured the water into the soda bottle with the oil, the water sank to the bottom. That's because water is heavier than oil. Scientists say that the water is more dense than the oil. If oil from a ship spills in the ocean, the oil floats on top of the water. To keep the lava lamp affect, make sure the cap stays on the bottle. But you may also want to leave on tub uncapped over night and see what happens. The water evaporates out and the tablet reforms at the bottom of the bottle.
Assessment
When the activity is done, have the students write down what they learned that day. This will help you determine if they understood the key concepts. You can also check their bottles to see if they followed instructions.
Standards
0.1.1.2.1 Scientific inquiry is a set of interrelated processes used to pose questions about the natural world and investigate phenomena.