Limestone and carbon dioxide
Students learn that acid solutions corrode calcium carbonate(limestone, marble), producing carbon dioxide.
Materials: a test tube, marble or limestone (small pieces or powder) , glass rode, tea spoon, hydrochloric acid (HCl), a pipette.
Procedure
- Put the marble (or limestone) into the test tube
- Using the pipette, half fill the test tube with hydrochloric acid. What do you notice?
What happens?
An immediate fizz appears, because the acid corrodes the marble and produces carbon dioxide. Also the fizz in soft drinks is carbon dioxide.
The reaction is:
2HCl + CaCO3 
CaCl + CO2 +H20