Lava Bottle

The lava bottle allows us to explore molecular polarity using simple household materials- water, oil, food coloring, and Alka seltzer. Molecular polarity sounds confusing, but it is just how much one molecule is attracted to another molecule with the same structure. For example, water molecules are attracted to other water molecules. Oil molecules are attracted to other oil molecules.

Molecules can either be hydrophilic (water-loving) or hydrophobic (water-fearing). Molecules with high polarity are hydrophilic and they mix well with other polar molecules.

Supplies

Vegetable oil

A bottle

Water

Funnel

Food coloring

Alka seltzer

Step 1:

Fill the bottle 1/4 with water

Fill the bottle 3/4 with oil

Leave 1 inch at the top

Step 2:

Add food coloring

Swirl the bottle

Wait...

Let the food coloring & water mix

Step 3:

Break the alka seltzer tablet

Insert one piece at a time

Be amazed!

Step 4: Experiment

To bring your bottle back to life just add another tablet!

You can experiment with your lava bottle by tinkering with a few things.

Does changing the temperature of your water make the bubbles last longer or make more bubbles?

What happens if you put the cap on the bottle after you put in the Alka seltzer?

How does the size of the bottle affect the number of bubbles produced?

Be curious and experiment!