This is the reaction pathway for the formation of calcium carbonate (CaCO3) from calcium chloride (CaCl2) through the following steps:

CaCl2 (calcium chloride) is dissolved in water to form Ca2+ and Cl- ions:
CaCl2 -> Ca2+ + 2Cl-

Calcium hydroxide (Ca(OH)2) is added to the solution, leading to the formation of a white precipitate of calcium carbonate (CaCO3):
Ca2+ + 2OH- -> Ca(OH)2 (precipitate)
Ca(OH)2 + Ca2+ -> 2CaCO3 (precipitate) + 2H2O

Carbon dioxide (CO2) is then bubbled through the solution, causing the formation of calcium bicarbonate (Ca(HCO3)2):
CaCO3 + H2CO3 -> Ca(HCO3)2

Overall, the conversion of calcium chloride to calcium carbonate involves multiple steps and reactions.