Sewell's Science

To make one of these lava lamps at home or indeed at a friends home you will need a few simple things; Water, Food coloring, oil (cooking or baby) and Alka seltzer tablets.  

 

Follow the steps in the video above on how to make them.  

 

The food coloring will only change to color of the water, not the oil. This is because the coloring is soluble in water but not in oil. 

 

Also the oil and water will not mix. Oil will always be on the top as it is less dense than water.  

 

In the alka seltzer tablets there is an acid and base in a powder form. Because they are in a powder form, they do not react until it is dissolved in water.  

 

When they do react carbon dioxide gas is produced. The gas is less dense than both water and the oil, so it carries a bobble of color to the top. This then pops and the color falls back down (giving the lava lamp effect).  

 

Most importantly remember, don’t try it at home try it at a friends home.

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