A substance A, when heated, releases a colourless gas and leaves behind a solid residue. This residue is dissolved in water to form solution B. When carbon dioxide is passed in excess through aqueous B, a solid C is produced and can be collected. On mild heating, solid C regenerates A. Ide

Question

A substance A, when heated, releases a colourless gas and leaves behind a solid residue. This residue is dissolved in water to form solution B. When carbon dioxide is passed in excess through aqueous B, a solid C is produced and can be collected. On mild heating, solid C regenerates A. Identify A.

Accepted Answer

CaCO3. Calcium carbonate (CaCO3) decomposes upon heating to release carbon dioxide (CO2) and leave behind calcium oxide (CaO) as a solid residue. When this residue is dissolved in water, it forms a solution that can react with excess CO2 to produce calcium carbonate again, which aligns with the regeneration of A.

A substance A, when heated, releases a colourless gas and leaves behind a solid residue. This residue is dissolved in water to form solution B. When carbon dioxide is passed in excess through aqueous B, a solid C is produced and can be collected. On mild heating, solid C regenerates A. Identify A.

Solution

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