Showing the reaction of bases and acids is a popular science experiment. You can make a project in which a volcano “erupts” or set off a paper rocket with this reaction. Baking soda and vinegar are what usually come to mind for this experiment. However, baking powder can have a similar reaction. Baking powder contains both acids and bases, but they will not react with each other while they are dry.
Acid and Base
To show the reaction of acid and base, you will need a cup of water. When a tbsp. of baking powder is mixed into the cup, a reaction will occur. To avoid making a mess, place the cup on a plate or bowl before combining the two ingredients.
Baking Powder Submarine
Use carrots to show how baking powder can push objects to the surface of water. Cut carrots about 2 inches long by 1/2 inch thick, and have rounded edges. Pre-cut baby carrots can be used instead. Once the carrot is cut in half length-wise, one half needs a small circular hole in the center of the flat side, about the thickness and depth of a pencil eraser. The hole should not go all the way through the carrot. Toothpicks broken in half can be inserted into the top non-flat portion of the carrot to make the carrot sink in a bowl of room-temperature water. If you remove the carrot from the water and pack the hole tightly with baking powder, a reaction will occur when the carrot is reinserted into the water, baking powder facing down. The carrot will now sink to the bottom of the bowl, rise to the top, and sink again.
You can use baking powder reactions to burst a bag. Using a 5 inch by 5 inch piece of paper towel, fold and insert 1 1/2 tbsp. of baking powder. Fill a plastic zip seal bag with 1/2 cup of vinegar and 1/4 cup of water, and place the paper towel in the bag -- but do not let it touch the liquid. While pinching the paper towel through the bag, seal the zip lock. Place the bag in the bathtub or outside and let the paper towel sink into the liquid, which causes the bag to puff up and pop.
Inflating a Balloon
Balloons can display baking powder reactions. Using a balloon filled with 3 tsp. of baking powder and a bottle 1/3 full of vinegar, put the balloon over the mouthpiece of the bottle. When the bottle is sealed and the baking powder is dumped from the balloon into the vinegar, the balloon will inflate.