What do you think these rocks are made from? They are just bicarbonate of soda ( Baking Soda ), water and food colouring.
We’ve made fizzing rocks before, they are very simple, but great fun to watch. I used a heart cookie cutter to get the shape.
What you need:
Water
Bicarbonate of soda/baking soda
Vinegar
Food colouring
Instructions
Mix some water with the bicarbonate of soda, I used a whole packet of bicarbonate of soda and just added water slowly until i had a very thick paste type mixture. Add a few drops of food colouring, mould into rock shapes and leave to dry for a few hours. Once the rocks have hardened, add vinegar very slowly and watch as they fizz and dissolve.
Once again, thanks to Reading Confetti for the idea.
Lorie
February 6, 2013 at 2:04 pmThanks for the link! We’re going to have to make some heart shaped rocks soon – my daughter would love it!
TheBoyandMe
February 6, 2013 at 11:55 pmI was going to do this, failed abysmally!
Notmyyearoff
February 7, 2013 at 11:41 amSuch a good idea…it reminds me of a bath bomb (although I would never use vinegar and it probably wouldn’t fizz the same!)
Aida
February 9, 2013 at 9:54 amreally cool idea
LauraCYMFT
February 9, 2013 at 2:48 pmThat is very clever!
maggy, red ted art
February 9, 2013 at 3:32 pmAnother great science experience! *Lovely* to have something for Valentine’s!
Thanks for sharing on Kids Get Crafty.
Maggy
The Good Stuff
February 9, 2013 at 5:50 pmway cool – love it…
Emma
February 10, 2013 at 2:50 pmI really should do more of your experiemnets and not just look and think oh great idea!
Coombemill - Fiona
February 10, 2013 at 5:19 pmWhat a great ideas – I can think of at least half a dozen kids that would try this.
ScienceSparks
February 10, 2013 at 8:59 pmLet me know if you do 🙂
Preschool teacher
February 19, 2013 at 2:32 amMy attempt at making these had some kind of reaction that looked like mold after a couple of days. Does baking soda mold after its mixed with food coloring and water?
ScienceSparks
February 19, 2013 at 8:16 amI think it is the type of food colouring, was yours bake stable?
Preschool teacher
February 19, 2013 at 4:47 pmMy food cooling was McCormick black I don’t see anywhere on it saying bake ready so maybe that is why I still am going to try this in the classroom because my 5 year old sat for a long time making the rocks fizz! Thanks for sharing!
ScienceSparks
February 19, 2013 at 8:14 pmBrilliant, I’m glad you liked it.
Emily
February 10, 2013 at 10:03 pmWe recently filled a volcano with cola and bicarbonate with incredibly messy consequences!
Stephanie
February 11, 2014 at 3:22 amCan I use baking soda for this experiment?