Final answer:
The given chemical reaction is a single displacement reaction, where magnesium replaces hydrogen in hydrochloric acid, forming magnesium chloride, hydrogen gas, and carbon dioxide.
Step-by-step explanation:
The reaction MgCO3 + 2HCl → MgCl2 + H2 + CO2 is an example of a single displacement reaction or a single replacement reaction. In such a type of reaction, one element replaces another element in a compound. In the given equation, the magnesium (Mg) in the carbonate (MgCO3) is combining with the chlorine (Cl) in hydrochloric acid (HCl) to form magnesium chloride (MgCl2), while the hydrogen (H) in hydrochloric acid is being displaced to form hydrogen gas (H2) and carbon dioxide (CO2) is also produced as a result of the reaction.