Baking Soda Balloon Science Experiment for Kids Materials Needed: 1 empty plastic bottle (about 16 oz works great) 1 balloon 2–3 tablespoons baking soda ½ cup vinegar 1 small funnel or a spoon Measuring cup Instructions: Fill the bottle – Pour about ½ cup of vinegar into the empty plastic bottle. Prepare the balloon – Use a funnel (or a spoon) to carefully add 2–3 tablespoons of baking soda into the balloon. Shake it gently so the powder settles inside. Attach the balloon – Stretch the balloon’s