Erupting Fruit Volcanoes

What is a volcano?

A volcano is an opening in the Earth’s crust.  It usually looks like a mountain.  When a volcano erupts hot gases and hot melted rock called lava escapes through the earth’s crust.  Lava is hot, very hot.  It’s temperature 1,300- 2,000 degrees Fahrenheit. After lava flows out of the volcano it cools down and hardens into rock.

Volcanoes are fun science experiments for kids.  They are not hard to make and fun to watch.

In this experiment you will first turn a piece of fruit into a volcano and second make it erupt by combing an acid and a base.

What Happens When you Mix an Acid and a Base?

When you mix an acid (in this experiment the fruit juice) and a base (in this experiment the baking soda)  it causes a chemical reaction.  Carbon dioxide is released.  In this experiment the carbon dioxide causes the eruption.

In this experiment we made volcanoes out of three different types of fruit; a lemon, apple and orange.

Question?

Which fruit volcano will have the biggest eruption? Which fruit makes the best volcano?

Let’s find out!

Materials needed:

Fruit: Lemon, Orange and Apple 2 of each in case a mistake is made. 

3 tablespoons of Baking soda

Dish soap (optional)

Food coloring (optional)

Three paper plates

knife (parent use only or parent supervision required)

Spoon

Step 1: Making the volcano

You need the fruit to sit on the plate without falling over.  To accomplish this, have an adult cut the very bottom of the fruit off.  Once each piece of fruit can sit on the paper plate without falling over, it time to make a hole in the middle.  Have an adult cut the top of the fruit off, you want to cut about 1/4 down from the top. 

If you are working with a a soft fruit such as an orange or a lemon use can make a hole by moving your spoon in a circular motion in the middle of the fruit.  If you are working with a harder fruit such as an apple, you will have to cut a hole in the middle of the using a knife.  The hole should be about 1.5-2 inches in diameter. Once your fruit has a hole, you can move on to step 2.

Step 2: Collecting the acid

Did you know that fruits such as lemons, apples and oranges are acidic.  Acidic means having a PH of  6 or lower.

Scientists use a PH scale to tell how acidic something is.  The scale runs from 0-14.  Anything that has a PH of 6 or lower is acidic.  Anything from 14-5 are considered bases. 7 is considered neutral.

Citrus fruits are acidic

Here are a list of acidic fruits

Lemons
Limes
Grapefruits
Pineapples
Peaches
Oranges
Apples
grapes
pomegranates
Tomatoes

For this experiment to collect the acid, you are going to squeeze the fruit.  The juice that come out is going to work as the acid.  Some fruits, such as apples are hard to squeeze, to get the juice we squeezed the left over pieces from making the hole in the middle. 

You are going to squeeze the juice into a bowl.  Make sure you collect as much juice as possible.  It is important the the bottom of the fruit stays intact so that no liquid can escape the bottom.  If the bottom is punctured you may need to start again. 

Optional Step 3: Color and Bubbles

This step is not needed but makes for a much cooler volcano. Add a couple of drops of the dish detergent into the center of your fruit’s hole.  Next add a couple of drops of food coloring and stir. 

Step 4 Adding the Base 

The baking soda will work as the base.  Add one tablespoon of baking soda to the middle the fruit. 

Step 5 The Eruption 

This is the best part.  Slowly add the juice back into the fruit. Make sure you add the lemon juice to the lemon, the apple juice to the apple and the orange juice to the orange. Your volcano should immediately erupt.  

Did your volcano erupt?

Which fruit had the best eruption?

Variations:

There are many ways you can try this experiment.

Instead of add the lemon juice back to the lemon, orange juice to the orange and the apple juice to the apple, switch it up.  Add the lemon juice to the orange or the apple juice to the lemon.  Did it work the same?  

Try using store bought juice.  Purchase lemon juice, apple juice and orange juice. Add them to the fruit.  Did you get a better eruption?  

How did your volcano turn out?  Did it erupt?  Send pictures of your erupting volcano to kidsplayandcreate@gmail.com and we may upload it to our site!