There's A Volcano In My Bathtub!

Experiments In Acid-Base Chemistry

What do you get when you mix an acid with a base?

A party!

"It is like the acid and the base like each other so much
that they make the best of bubbly friends."

This is one way that I explain the fun, interesting chemical reaction of acid/base mixing to little kids. I also make sure we talk a bit about the ph scale; where an acid and a base are on that scale; and how when mixed together, they meet in the middle becoming neutralized.

Mini Bathtub Volcanoes

Mini Bathtub Volcanoes

Acid & Base Fun For Little Ones

~ A Very Simple Experiment ~

Demonstrating this reaction for kids is easy.  Put a spoonful of baking soda in a clear glass then add a bit of vinegar and watch the bubbles!  This is a great time to talk about what exactly is happening inside the glass.

~ Blow Up A Play Dough Volcano ~

Every year we make a volcano at preschool filling it with a mix of baking soda, vinegar and food coloring to create an explosion!  It is always a major hit with the kiddos.  They love watching the volcano erupt over and over and over again.

This year we made our volcano with left over rose bud play dough and blue lava, kid's choice!

This year we made our volcano with left over rose bud play dough and blue lava, kid's choice!

The coloring started to run out but bubbly white is fun too!

The coloring started to run out but bubbly white is fun too!

Materials ~ 

  • Play Dough, this is the perfect time to use up any old play dough you have lying around.
  • Vinegar, lots of it!  (this is the acid)
  • Baking Soda, lots of this too!  (this is the base)
  • Food Coloring, optional.  For our next volcano I think I will try using  beet powder instead to color our lava.  I love to find natural alternatives to food coloring.
  • A Pan with high sides

Instructions ~ Shape a volcano from play dough in your pan.  Use your hands to form a play dough cone, get the kids involved they love it! After you gather your audience, put some baking soda and coloring inside the volcano then add some vinegar and watch the fun!  If your kids are anything like mine, they will probably want you to blow it up again and again! It is fun to add a few "vents" by poking holes along the side of the volcano so the lava comes out there too.

~ Create Bathtub Volcanos ~

Mini Bathtub Volcanoes

Mini Bathtub Volcanoes

Follow up your volcano with mini bathtub volcanos for the kids to take home with them.  It is the perfect way to extend the learning and the fun!  These really are bath bombs; did you know that fun fizzing of bath bombs is all about acids and bases reacting?  Here is how to make your own! Materials ~ 

  • 1 cup Baking Soda
  • 1/2 cup Powdered Citric Acid  (this is the acid)
  • 1/2 cup Epsom Salts
  • about a tablespoon of Witch Hazel
  • 10 to 20 drops of Essential Oils, favorite kid safe options are lavender, sweet orange, rose geranium, cardamom, spearmint and ylang ylang.  We used lavender to keep things simple.
  • 1 teaspoon Oil, like almond, apricot kernel or olive oil .  We used a calendula and lavender infused almond oil.
  • Molds, we used plastic eggs to make tiny volcano shapes; I also brought some soap molds that I have on hand so kiddos could have a choice.

There are lots and lots of bath bomb recipes online.  After researching I decided to based our super simple bath bombs off Mountain Rose Herbs beautiful Rose & Geranium Bath Bombs.

mixing

mixing

 Instructions ~ First it is really fun to run another simple little experiment with the kids so they know exactly what is happening with these mini volcanos.  Once again we created an acid/base mix in a glass by putting one spoonful of baking soda and a 1/2 spoonful of citric acid in the glass.  And what happened?  Nothing.  Nothing happens until you get water involved.  So we added some water and bubbles! Next we made our volcano bath bombs.  If you are making this with a group of kids, I really recommend practicing because the process is a tiny bit fussy. First, mix all the dry ingredients together making sure to break up any lumps.  Carefully add the oil and essential oils while stirring to limit any bubbling action in your bowl. Finally add the witch hazel a bit at a time, again stirring while you go.  I actually put the witch hazel in a spritzer bottle and spray it in to the mixture a couple squirts at a time.  This worked really well for me.  Keep spraying and mixing until the mixture holds together when you squeeze it in your hand. Mold the bombs with the kids by having them tightly pack the mixture into a mold. ~ as I said I brought in a few different shapes to choose from with plastic eggs as one choice.  Using half off a plastic egg creates a little volcano shape.  You can use what ever you have on hand and even just shape them with your hands by squeezing the mixture into whatever shape you want.

Using A Heart Shaped Mold

Using A Heart Shaped Mold

Pressing mixture into a plastic egg.

Pressing mixture into a plastic egg.

Let the bath bombs dry for a few days before using.  So the kids don't miss out on the fun make sure to let them know to get into the tub before they put the bath bomb in because it only fizzes for a minute or so.

Do you have a favorite way to experiment with acids and bases?

Our Volcanoes/Bathbombs

Our Volcanoes/Bathbombs