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General Chemistry Science Fair Project

Salt and Oil Density Lava Lamp

Easy
Salt and Oil Density Lava Lamp | Science Fair Projects | STEM Projects
Does salt sink or float in oil? Salt is much denser than oil, so it drops straight to the bottom. But on the way down, it drags a blob of oil with it. You pour cooking oil over colored water in a clear glass. Then you sprinkle salt on top of the oil. The heavy salt pulls oil blobs down through the water. When the salt dissolves, the oil is released and floats back up. This creates a repeating lava-lamp effect powered by nothing more than salt, oil, and water.

Hypothesis

The hypothesis is that pouring salt on top of oil in water will create an erupting salt volcano.

Method & Materials

You will pour water into a glass jar, add oil on top of it, and then sprinkle salt on the oil. As the salt dissolves, it will create an exciting eruption!
You will need a glass jar, vegetable oil, salt, water, and optional food coloring for an extra touch of color.

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Results

When salt is added to oil on top of water, it drags oil droplets down into the water. When the salt dissolves in the water, the oil rises back up in bursts, causing the lava eruption effect. This demonstrates the principles of density and immiscible liquids.

Why do this project?

This science project is interesting because it allows you to create a fascinating visual display using everyday materials. It also helps you understand the concepts of density and immiscibility in liquids.

Also Consider

Try using different types of oil and observe if there are any differences in the eruption. Add other substances, such as vinegar or baking soda, to see how they affect the volcano's eruption.

Full project details

Additional information and source material for this project are available below.

Related videos

These videos explain the science behind this project and demonstrate key concepts used in the experiment.
Join the Fleet Science Center as they guide you through creating a salt volcano lava lamp and uncovering the fascinating science behind it!
Check out this effective way to make the lava lamp effect by pouring in the salt quickly in a circular motion!
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