The chemical reactions shown above represent the transformation of calcium carbonate (CaCO3) into calcium nitrate (Ca(NO3)2) through a series of steps.

Calcium carbonate (CaCO3) is first heated to produce calcium oxide (CaO) and carbon dioxide (CO2):
CaCO3 —> CaO + CO2

Calcium oxide (CaO) reacts with water to form calcium hydroxide (Ca(OH)2):
CaO + H2O —> Ca(OH)2

Calcium hydroxide (Ca(OH)2) can react with carbon dioxide (CO2) to reform calcium carbonate (CaCO3):
Ca(OH)2 + CO2 —> CaCO3 + H2O

Finally, calcium carbonate (CaCO3) can react with nitric acid (HNO3) to produce calcium nitrate (Ca(NO3)2):
CaCO3 + 2HNO3 —> Ca(NO3)2 + CO2 + H2O

Overall, the series of reactions outlined above demonstrates the conversion of calcium carbonate to calcium nitrate through a combination of thermal decomposition, hydration, and acid-base reactions.