Carry out the transformations: CaCO3- Cac2- C2H2- CO2- Ca (HCO3) 2- CO2- CO.

Explanation of the solution:
1) interaction of calcium carbonate with carbon with the formation of calcium carbide and carbon monoxide;
2) obtaining acetylene as a result of the interaction of calcium carbide with water;
3) complete combustion of acetylene in an oxygen atmosphere with the formation of carbon dioxide;
4) interaction of carbon dioxide with calcium oxide;
5) the formation of calcium bicarbonate;
6) the formation of a medium salt of calcium carbonate;
7) its thermal decomposition;
8) CO2 + coal