Making a baking soda volcano
  • } Target year group: year 3 and up (any year if supported)
  • c Time: 45 minutes to 1 hour
  • u Links with art and outdoor learning

Learning objectives

To learn about the properties of chemical substances.

Resources needed

  • Play-doh or papier-mâché
  • A plastic jar
  • Red food dye
  • Warm water (acts as an accelerant)
  • Bicarbonate of Soda
  • Vinegar

 

Instructions

The first step is to build the volcano—wrapping a jar in Play-Doh will do the trick, or use papier-mâché for those feeling a bit more ambitious. Decorate it with whatever scraps you have or some natural items from a park or garden, like pebbles, grass and flowers. Go outside or prepare for some clean-up inside.



To erupt your volcano:

1. Add two or three teaspoons of bicarbonate of soda to your plastic bottle/jar.

2. Pour in half a glass of warm water mixed with the red food dye.

3. Pour in approximately a glass full of (inexpensive) vinegar.

 

How to put the idea into practice

Provide assistance in gathering all materials and supervise the mixing of the substances.


Explain how it works

The baking soda (sodium bicarbonate) is a base while the vinegar (acetic acid) is an acid. When they react together they form carbonic acid which is very unstable, it instantly breaks apart into water and carbon dioxide, which creates all the fizzing as it escapes the solution.

Download these instructions in a printable PDF

 

Follow-up question: 

Does the shape of the volcano affect the direction the eruption travels?