Carbon dioxide gas

Aim: To show that carbon dioxide gas is produced when a metal carbonate reacts with an acid

Equipment:

• Two boiling tubes
• delivery tube and bung
• Bunsen burner
• Test tube rack
• Wooden splint
• A bottle of acid
• A small amount of metal carbonate
• Test tube tongs
• Safety glasses

Method:

1. Add a pea-sized amount of metal carbonate into one of the boiling tubes
2. Place this boiling tube into a test tube rack. Ensure you have the bung and delivery tube ready
3. Add 5ml of acid to the boiling tube with your tongs, capture the gas produced as shown in the diagram 
4. 
   
5. When you think the tube is full, your lab partner should light a wooden splint
6. Carefully remove the boiling tube from under the delivery tube, taking care to keep it facing upright.
7. Insert the burning splint into the mouth of the test tube.

Results

The flame on the splint went out almost immediately. My group and I described it as almost being choked.

Discussion
The reason for the flame going out was because there wasn't any oxygen in the tube, just carbon dioxide. This carbon dioxide was created through a reaction between calcium and hydrochloric acid. This as a word equation would be written as Calcium Carbonate + Hydrochloric = Calcium Chloride + Carbon Dioxide + Water.

Conclusion
The experiment worked which proves that carbon dioxide is formed when a metal carbonate reacts with an acid.