We have recently created "bath bombs" in our chemistry class and I was wondering what it was in these bombs that made them react with(creates a fizz) and then they become soluble in water. Here is the materials list. -citric acid -sodium hydrogen carbonate -olive oil -cornstarch -ester(we created our own) We mixed the citric acid, cornstarch and sodium hydrogen carbonate first, then mixed in the olive oil and ester. Then we let it sit for 2 days.... What is it that makes it react with water? Is it the NaHCO3?