* Calcium carbonate (CaCO3)

* Hydrochloric acid (HCl)

Procedure

1. Half-fill a beaker with calcium carbonate.

2. Add hydrochloric acid slowly, stirring constantly.

3. Continue adding hydrochloric acid until all of the calcium carbonate has reacted and the solution is clear.

4. Evaporate the solution until it crystallizes.

5. The crystals are calcium chloride (CaCl2).

Chemical Equation

CaCO3 + 2HCl → CaCl2 + H2O + CO2