Take several marble chips and place them in the bottom flask. This will serve as one of the reactants for the production of carbon dioxide. Ensure the entire bottom of the container is covered with marble chips.
Insert a thistle funnel into the flask with the marble chips at the bottom of the container. Ensure that the funnel is tightly fitted in the mouth of the container to prevent gas from escaping.
Attach a tubing on the side of the flask. This tubing will collect the gas from inside of the flask and transfer it into another flask or bottle.
Pour a small amount of diluted hydrochloric acid solution through the funnel. Observe the reaction between the acid and the marble chips.
Direct the students to observe the bottle that collects the gas formed from the reaction. Tell students that the reaction between hydrochloric acid and marble chips produces carbon dioxide. Review the characteristics of carbon dioxide and ask the students to compare those characteristics with the gas that was collected in the bottle.