A solid compound X on heating gives CO2 gas and a residue. The residue mixed with water forms Y. On passing an excess of CO2 through Y in water a clear solution Z is obtained. On boiling Z, compound X is reformed. The compound X is:

A solid compound X on heating gives CO2 gas and a residue. The residue

1.	A solid compound X on heating gives CO2 gas and a residue. The residue mixed with water forms Y. On passing an excess of CO2 through Y in water a clear solution Z is obtained. On boiling Z, compound X is reformed. The compound X is:
Answer» A solid compound $X$ on heating gives $C O_{2}$ gas and a residue. The residue mixed with water forms $Y$ . On passing an excess of $C O_{2}$ through $Y$ in water a clear solution $Z$ is obtained. On boiling $Z$ , compound $X$ is reformed. The compound $X$ is: