Question: Make a pop noise by mixing two chemicals together.
Options:
Take equal volumes of vinegar and water, about a half cup each.  Place each in a plastic soda bottle and push a cork into the top.  The reaction between acid and base will make a gas and expel the cork. It will pop.
Take equal volumes of vinegar and baking soda, about a half cup each.  Place each in a plastic soda bottle and push a cork into the top.  The reaction between acid and base will make a gas and expel the cork. It will pop.
Answer: Take equal volumes of vinegar and baking soda, about a half cup each.  Place each in a plastic soda bottle and push a cork into the top.  The reaction between acid and base will make a gas and expel the cork. It will pop.