This reaction pathway involves the following steps:

CaCO3 (calcium carbonate) is heated to form CaO (calcium oxide) and CO2 (carbon dioxide) gas.CaO reacts with water to form Ca(OH)2 (calcium hydroxide).Ca(OH)2 reacts with CO2 to form CaCO3 once again.CaCO3 reacts with HNO3 (nitric acid) to form Ca(NO3)2 (calcium nitrate).

Overall, this reaction pathway involves the conversion of calcium carbonate to calcium nitrate through a series of chemical reactions.