Erupting Volcano ~ G-Free~ Arm and Hammer!

Erupting Volcano
Build Your Very Own Volcano and Watch It Erupt!
This is an old favourite that's a staple at Science Fairs—-it's so popular because it's so reliable and easy! You can do this in the sink just to see the 'lava', or make the volcano as directed below.

Remember the importance of adult supervision, especially with young children.

Supplies needed:

cardboard
plaster-of-paris
4 oz. plastic cups
red food colouring
water
ARM & HAMMER® Baking Soda
hand dishwashing liquid
vinegar or citric acid (sour salt)

Making the Volcano:

Step 1: On a baking sheet or other easily cleaned surface, shape cardboard into broad cone shape, using a 4 oz. cup to form the "crater" at the top of the volcano.

Step 2: Use the plaster-of-paris over the cone to form the volcano. Do not get plaster in the crater. Allow volcano to dry completely.

Step 3: Paint or decorate volcano as desired. If you would like your volcano to stand up to repeated eruptions and clean-ups, consider using non-water soluble paints.

Making the Eruption:

Step 1: Mix ¼ cup vinegar (or 1 teaspoon citric acid) with dishwashing liquid, water and red colouring in a plastic cup

Step 2: Put 1 teaspoon ARM & HAMMER® Baking Soda in an empty plastic cup. Place this cup inside the volcano crater.

Step 3: Quickly pour vinegar/dishwashing liquid/water mixture into the ARM & HAMMER® Baking Soda cup in the crater. Enjoy the lava as the volcano erupts!

Explanation:
The ARM & HAMMER® Baking Soda reacts with the vinegar (or citric acid) in the mixture and produces a gas, carbon dioxide (CO2). As the gas is released it bubbles through the dishwashing liquid, creating the bubbly, red lava.

Variations:

Experiment with different mixes of vinegar/dishwashing liquid/water solutions or slurries of the ARM & HAMMER® Baking Soda. Vary which component is added to the crater first, to create different visual effects.