• Skip to primary navigation
  • Skip to main content
  • Skip to primary sidebar
Menu
  • Science Experiments For Kids
  • Science Fair Projects
  • Science Facts
  • Science Questions
  • About
    • Emma Vanstone
    • About Science Sparks
Science Experiments for Kids
Menu
  • STEM Challenges
    • STEM Challenges
    • FREE STEM Challenge Templates
  • Early Years Science
    • Preschool Science
    • Sensory and Messy Play
    • Understanding of the World
    • Pirate Science Experiments
  • Primary Science
    • Baking Soda Experiments
    • Candy Experiments
    • Biology
    • Climate Change for Kids
    • Coding for Kids
    • Chemistry
    • Electricity for Kids
    • Magic Science Experiments
    • Harry Potter Experiments
    • Human Body Science
    • Air Pressure Experiments
    • Life Cycles
    • LEGO Science Experiments
    • Kitchen Science
    • Famous Scientists
    • Forces and Motion
    • Science Sparks Snippets
    • Key Stage 1 Science
      • Animals
      • Everyday Materials
      • Plants
      • Coding Activities
      • Humans and Health
      • Fine Motor skills
      • Science and Literacy
    • Key Stage 2 Science
      • Animals, Including Humans
      • Electricity
      • Light
      • Plants
      • Materials and their Properties
  • Holiday Science
    • Christmas Science
    • Halloween Science
    • Easter Science
  • Storybook Themed Science Experiments
  • Wonderful Women in STEM
  • FREE Science Resources
menu icon
go to homepage
search icon
Homepage link
  • FREE Experiments
  • Science for Kids
    • Kitchen Science
    • Climate Change
    • Egg Experiments
    • Fairy Tale Science
    • Edible Science
    • Human Health
    • Chemistry
    • Inspirational Women
    • Forces and Motion
  • Science Fair Projects
  • STEM Challenges
  • Science Sparks Books
  • Contact Science Sparks
  • Science Resources for Home and School

×
Home » Early Years Science » Fizzy Hidden Coin Pirate Rocks

Fizzy Hidden Coin Pirate Rocks

Modified: May 21, 2025 · Published: Feb 18, 2015 by Emma Vanstone · This post may contain affiliate links · 1 Comment

These fizzy pirate coins are super simple to make and lots of fizzy fun. We used food colouring to make the baking soda look like rocks and added shiny coins for the children to find.

First, we cleaned up some pennies to make our shiny pirate coins. To do this, we simply placed them in Coca-Cola and vinegar. As you can see from the second photo, both did a good job. The coin in the middle was in water for the same amount of time.

Coins soaking in vinegar to clean them
shiny coins after soaking in vinegar
Coins cleaned after soaking in vinegar

Once we had our shiny coins we set about making the rocks.

What you need to make fizzy pirate rocks

Baking soda

Food colouring

Water

Coins

Vinegar

Optional – flour

Instructions

Pour your baking soda into a bowl and add water slowly until it makes a paste.

Add a couple of drops of food colouring and mix well.

Either mould with your hands or use cake moulds to create shapes. Press a coin into each.

Leave in the fridge overnight.

If you wanted to pad out the baking soda a little, add some flour when you mix. As long as it’s not more than half and half you should still get a good reaction.

fizzy pirate rocks made with baking soda

We added some coloured rice to make it look a little more appealing and then used a pipette to drop vinegar onto the coins.

fizzy pirate rocks

Why does this happen?

Vinegar (an acid ) and bicarbonate of soda ( an alkali ) react together to neutralise each other. This reaction releases carbon dioxide ( a gas ) which is the bubbles you see.

More fizzy pirate fun

These exploding treasure chests from Fun A Day look brilliant!

Make fizzy baking soda rocks and hide pirate coins inside. Fun pirate science experiments for kids #pirates #pirateparty #piratescience #piratepartyideas #piratesforkids

Last Updated on May 21, 2025 by Emma Vanstone

More Early Years Science

  • ideas for learning with LEGO
    40 Easy Science Experiments Using LEGO®
  • Firework Crafts – Spin Art and Filter Paper Pictures
  • Tennis ball bouncing
    Why do balls bounce?
  • 20 AWESOME Outdoor Science Experiments for Kids

Safety Notice

Science Sparks ( Wild Sparks Enterprises Ltd ) are not liable for the actions of activity of any person who uses the information in this resource or in any of the suggested further resources. Science Sparks assume no liability with regard to injuries or damage to property that may occur as a result of using the information and carrying out the practical activities contained in this resource or in any of the suggested further resources.

These activities are designed to be carried out by children working with a parent, guardian or other appropriate adult. The adult involved is fully responsible for ensuring that the activities are carried out safely.

Reader Interactions

Leave a Reply Cancel reply

Your email address will not be published. Required fields are marked *

Primary Sidebar

Welcome!

Imagine a world where science education is accessible to everyone and is all about hands-on, exciting discoveries. That’s the world I want to create.

More about me

Around the World in 50 Experiments

50 experiments about countries of the world

Footer

↑ back to top

Science Sparks - FREE science experiments for kids

Newsletter

  • Sign Up! for emails and updates

Contact

  • Contact
  • Privacy Policy
  • Services
  • Media Kit
  • FAQ

As an Amazon Associate, I earn from qualifying purchases.

Copyright © 2025 Science Sparks - Wild Sparks Enterprises Ltd