Vinegar and Baking Soda

Here is another way to do the baking soda and vinegar experiment. You did it in a Ziploc bag, but here they are doing it in a bottle with a balloon. Which statement best explains what happened?

BillyBill: “I think that a new substance formed when the soda was poured into the bottle because the balloon blew up a little.”

SusieSus: “I think that a new substance formed when the soda was poured into the bottle; and when the vinegar and baking soda were combined, they both blew up the balloon a little.”

Jimothy: “I think that neither one had a new substance form because the vinegar and baking soda are still vinegar and baking soda, and the soda is still soda.”