Homemade Lava Lamps!

posted by Gina

Age Range: 5 and up.

This is a nifty (dare we say groovy?) experiment that kept Larry the Cat amused for several hours today – ensuring its success with your kiddo.

You Will Need:

New Kitchen! Shiny Kitchen!

Behold Gina’s new apartment!

  • An empty bottle – those schmancy designer water bottles work well (as do empty – erm – adult bottles, as pictured above), but any empty, clear bottle will work just fine
  • Oil
  • Water
  • Food coloring
  • Alka-Seltzer tablets

Procedure:

1.  Fill the bottle between a-little-over-half to  2/3 full of oil.

DSCN0637

2.  Fill the bottle the rest of the way with water, leaving an inch or so on top.

DSCN0638

Watching the water settle is fascinating on its own.

3.  Add 10 or so drops of food coloring.

DSCN0639

You’ll see the drops travel through the oil and settle into the water, coloring the water but not the oil.  Neat!

4.  Drop in a piece of Alka-Seltzer … and watch the magic.

DSCN0653

Continue to drop in Alka-Seltzer as the bubbles die down to keep the Lamp moving.

Lessons Learned:

  • Waiting for the oil and water to really settle makes the Lava Lamp effect work way better.  However, rushing the process will give you some interesting effects:
DSCN0646

Too soon.

  • Breaking the Alka-Seltzer into smaller piece – four to five a tablet – will keep your Lamp from getting cloudy.

Why does this work?

It’s all about density.  What is density?  Imagine you have two items that are the same size, but have different weights.  The one that weighs more is more dense – meaning it has more matter packed into it. Those “Will this float?” experiments we’ve all done are merely exercises in determining which objects are more dense than water.

When you first mix the water and the oil, the water sinks to the bottom and the oil floats on top.  That’s because water is more dense than oil.

The Alka-Seltzer contains contains citric acid and sodium bicarbonate (baking soda). Those two ingredients react in the water, making a fizz – tiny bubbles of gas.  This gas is less dense than the oil, so bubbles of the now-colored water is carried with the gas through the oil.  Amazing!

Curriculum Connection:  Science!

Related Link:

  • Here are some more fun kitchen experiments with density – including making vinaigrette and layered drinks.
Advertisements

One thought on “Homemade Lava Lamps!

  1. Pingback: A Blast from the Past | lobestir

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s