1, calcium carbonate and dilute hydrochloric acid reaction of the chemical equation is: CaCO3 + 2HCL == CaCL2 + CO2 ↑ + H2O, complex decomposition reaction is by two compounds to exchange each other's composition, to generate two other compounds of the reaction.

2, calcium carbonate is an inorganic compound, chemical formula CaCO?, commonly known as gray stone, limestone, stone powder, marble and so on. Calcium carbonate is neutral, basically insoluble in water, soluble in hydrochloric acid. It is one of the common substances on earth, present in aragonite, calcite, chalk, limestone, marble, travertine and other rocks, but also for the main components of animal bones or shells.

3, dilute hydrochloric acid that is less than 20% of the mass fraction of hydrochloric acid, the chemical formula of the solute is HCl. Dilute hydrochloric acid is a colorless, clear liquid, strongly acidic.