Do Oil and Water Mix? Three Experiments for Elementary Students

By Carole Bruzzano

You may be thinking that oil and water don't mix. But students will tell you differently when they produce evidence to counter that claim. These three oil and water experiments teach the concepts of solubility and emulsion. Hassle-free, high interest learning is certain!

Let's Experiment!

Teach new and unfamiliar content in creative ways. Through the use of simple materials and easy to follow steps, students will learn important science concepts while exploring the properties of oil and water. Dish soap, food coloring, a plastic container, a tablespoon and of course the stars - oil and water - are the only materials needed for the experiments presented here. Minimal preparation and clean up are required, but high levels of student learning will result - a perfect combination for the elementary science classroom.

Materials and Vocabulary Terms

Before beginning these three oil and water experiments, prepare the materials needed. Also, plan on teaching students the new vocabulary terms, solubility and emulsion.

First, gather and prepare the following materials before the start of these lessons:

  • 2 tablespoons of cooking oil (such as vegetable, corn or canola)
  • 1 cup of water
  • 1 clear plastic container with lid (or plastic soda bottle with cap)
  • 1 bottle of food coloring
  • 1 tablespoon of liquid dish washing soap

Next, introduce these new vocabulary terms to students:

  • solubility
  • emulsion

To teach these terms, you may want to use a reliable strategy such as explicit instruction (have students say the word, spell it, define it, and then use the word during the experiment process). Also, use these words when speaking to the students during the lesson periods while students are conducting the experiments.

Experiment 1: Mixing Oil with Water

Once materials are ready and the new vocabulary terms have been introduced to the students, create groups of three or four students. Then, distribute the materials. Begin the first oil and water experiment as presented here.

Helpful tip: Provide these steps as written directions on the board or on a handout sheet to distribute to each group.


Step 1: Fill the plastic container with the cup of water.

Step 2: Add the 2 tablespoons of cooking oil into the water.

Step 3: Cover the container with the lid. Be sure it is tightly sealed.

Step 4: Shake the container to mix the oil and water.

Step 5: Place the container down and remove the lid to observe what happens.

Students will observe that the oil and water separate even after mixing. The oil will rise to the surface of the water.

Step 6: Have students write down the process used to conduct this experiment, as well as their final observations. Then, have students share their results with the class.

Experiment 2: Adding Food Coloring to Oil and Water Mixture

For this experiment, students will observe that food coloring does not mix with oil but mixes with water. Instruct students to follow steps 1 through 5 (see first experiment). Then, students continue with step 6 as presented here.

Step 6: Add a few drops of food coloring to the oil and water mixture.

Step 7: Cover the container with the lid and shake the container.

Step 8: Place the container down and remove the lid.

Step 9: Observe what happens over the next few minutes and write down observations.

Students will observe the oil separating from the water and rising to the surface. They will also observe that the food coloring mixes with the water, but not with the oil. Have students record the process followed for the experiment in addition to these observations.

Experiment 3: Combining Oil and Water

For this experiment, students learn the process of emulsion. This is done by adding soap to an oil and water mixture. Repeat steps 1 through 5 from the first experiment, then continue on to step 6 presented here.

Step 6: Add a tablespoon of dish soap to the oil and water.

Step 7: Place the lid on the container and shake the container.

Step 8: Place the container down and remove the lid.

Step 9: Record observations.

Students will observe that water, oil and soap mixed together. Use this experiment to teach about emulsion. Have students compare these results with the results from the two previous experiments. Instruct them to identify the similarities and differences.

Helpful hint: Explain to students that soap acts to dissolve the oil allowing the oil and water to mix together (the emulsion process).

Beyond Oil and Water Experiments

For upper grade elementary students, present a learning challenge by teaching the molecular structures of water and oil. Or, use these basic experiments to progress to more complicated mixtures beyond food coloring. Many options are available. Density, for example, can be taught by using other substances in the mixture. This extension provides the perfect opportunity for students to learn, understand and apply new science terms such as solution, property and viscosity. Your students will be active learners gaining understanding of new science concepts in engaging and challenging ways. That's one reason why students enjoy the science classroom.