Answer:
Step-by-step explanation:
If you are not increasing the amount of vinegar, the adding more baking soda has nothing to react with. The limiting reagent is vinegar (or some other acid).
The usual reaction is
HC2H3O2 + NaHCO3 ===> NaC2H3O2 + HOH + CO2 which is the gas being expelled.
If you increase the NaHCO3 nothing more will happen until you increase the vinegar.