Valentine’s Day Science Chemical Reaction


Kids to love celebrate. Even something like Valentine’s Day becomes very exciting for kids of all ages. Whether at home or in the classroom, kids will love creating this chemical reaction!

Valentine’s Day landed on a day that we had science this year. I wanted to plan something fun for science, but also continued our learning in science class. This experiment is perfect!

Although I used this chemical reaction experiment for Valentine’s Day, you could use it for any time of year or for any special themed day. All you really need is baking soda and vinegar!

I knew that the kids were going to love it! In kindergarten any bubbles (or explosions!!!) cause a lot of excitement, and learning! 

valentines day chemical reaction


One of the main things that I love about this experiment is that you don’t need to search for any special materials. A friend of mine calls it kitchen science because you are using things that you (probably) already have in your kitchen. You will need:

  • Baking Soda
  • White Vinegar
  • Heart Gems
  • Heart or Circular Mold
  • Red Food Colouring
  • Eye Droppers (Optional)
chemical reaction

Preparing Your Chemical Reaction Experiment

I started by mixing baking soda with water. You want the mixture to be roughly the consistency of cupcake batter. If it is wetter, it will still work it will just take longer to dry.

chemical reaction

Into your baking soda and water mixture, add red food colouring. You can add a little to turn your mixture pink, or add lots to make it red.

In the bottom of the mold, place a heart gem or two. These will be the special surprise that children will find when they do the experiment.

chemical reaction

Next, use a spoon to put the mixture into the molds. Press the mixture down so that all parts of the mold are filled.

If you have kids that are eager to help, they can scoop the mixture into the molds by hand.

Let the mixture in the molds dry. This can take 24 hours depending on how wet your mixture is. When there is no water on the top and the baking soda is hard, they are ready to come out.

valentines day chemical reaction experiments

Some molds work better than others, so test that you can get the baking soda puck out of the mold by testing one puck first. If it comes out easily then you know the pucks are dry and ready.

Introducing the Science Experiment

Always supervise children during science experiment. Remind children not to eat or taste the materials.

Once you have all of your baking soda pucks removed from the mold, you are ready to do the experiment. I made a lot of the baking soda pucks because I move between several classes and created this chemical reaction with many kids.

chemical reaction experiments

I used eye droppers for experiments like this with a chemical reaction. They allow kids to slowly and precisely place a drop of vinegar onto the baking soda versus dumping a lot of vinegar on top.

chemical reaction

Every time I bring out eye droppers at school, or at home with my own kids, they are always excited. The eye droppers make them feel like a real scientist! Link at bottom.

I placed one baking soda puck into a plastic bowl for each child. I also gave everyone an eye dropper and a small bowl with vinegar in it.

To start, I have everyone look at and explore the materials for experiment, but not actually mixing anything yet. We predicted what we thought was going to happen.

chemistry valentines

Valentine’s Day Science Experiment

I showed everyone how to use the eye droppers and then we began. Everyone filled their eye droppers with vinegar and dropped one drop of vinegar onto the baking soda puck.

What happened??? There was a lot of excitement in the room as room as the vinegar touched the baking soda and the chemical reaction occurred.

As soon as the vinegar touches, the baking soda and vinegar react to each other and cause a chemical reaction – an “explosion” as my children call it. It is really interesting to watch!

chemical reaction experiments

The surprise was that in each mold was a heart gem for each student to discover and take home.  I did not tell the children that there was a surprise, but as they watched the chemical reaction, they began to see the gems at the bottom.

Some children choose to use magnifying glasses to closer inspect their chemical reaction. This is a great addition to the experiment. If you have a magnifying glass, kids are able to closer inspect the reaction.

During the experiment, children also noticed that when they added the vinegar, they heard that it was making a fizzing sound.

Make sure to listen to the video! The sound it makes is one of the best parts!

When doing science experiments, encouraging children to their senses is a great way for kids to learn about the world around them and fully observe everything as they do the experiment. (Except their sense of taste – do not eat the materials used for this experiment!)

A simple science experiment and chemical reaction like this, is a great way to celebrate Valentine’s Day. It is simple enough to do at home or in the classroom and kids will love it!

chemical reaction

Chemical Reaction Experiment Extension Ideas

Although I created small baking soda hearts and gave one to each child, you could easily create a larger baking soda puck. The larger it is, the longer it will take to dry.

You could create a large puck and have a group of children work on finding the gems. Or if you create it at home, you could add extra hearts and gems and give a large puck to your child to do on their own.

valentines day science

Larger hearts are easier to create so if you are working with a large group, you can simply make 10 large baking soda pucks and share between several kids.

Have fun celebrating Valentine’s Day this year as you bring in a bit of science to your celebration.

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