I get asked everyday by kindergarteners if I am going to do a science experiment with them. Since they are so keen on science, and our program is inquiry based, I have been striving to do more and more experiments. This is an easy science experiment that always gets a lot of reactions and creates a lot of discussion. All you need is a balloon, a water bottle, baking soda and vinegar. The vinegar in my photos is only yellow because I added food colouring so that the reaction is easier to see.
I always like to introduce this experiment with the fact that I am going to blow up the balloon without the balloon ever touching my lips. Students then guess how I am going to do it. There are always some great guesses! I have prepared a balloon filled with baking soda and filled the water bottle with vinegar. I drew a picture of a smiley face, just for fun. We always think of a hypothesis before we start and then I tip the balloon into the bottle. As soon as the baking soda mixes with the vinegar, there is an immediate chemical reaction. It starts to bubble and makes a fizzing noise. It is a great chance to encourage students to use their sense of hearing because they will quietly listen in order to hear it.
Slowly, the balloon will start to inflate and get bigger and bigger. Children always love watching the balloon blow up right before their eyes. We then discuss what happened and why they think it happened. I also try to let students have a chance to feel the bottle because the vinegar now feels cold. I briefly explain that for the reaction to happen, it draws heat from around it, which then makes the bottle with the mixture feel cold. Isn’t science exciting!