What role does the long-necked funnel play in the experiment of producing carbon dioxide?

1. Adjust the internal and external pressures to be consistent.

Add acid

3. Prevent gas leakage

It is important to control the reaction at any time. For example, when there is enough gas, the airway will be clamped, and the hydrochloric acid in the bottle will be squeezed into the long-necked funnel by air pressure, and the reaction will end, otherwise the reaction will start.