The gas A is bubbled through lime water , a while precipitate is formed . This precipitate dissolved on prolonged bubbling the same gas. On heating this solution, the white precipitate reappears with the evolution of gas B . The gases A and B respectively are

Options

A. `CO_(2)` and CO
B. CO and `CO_(2)`
C. CO and CO
D. `CO_(2)` and `CO_(2)`

Answer

D

Explanation

According to the eqation,
`Ca(OH)_(2)+CO_(2)rarrCaCO_(3)+H_(2)O`
`CaCO_(3)+H_(2)O+CO_(2)rarr Ca(HCO_(3))_(2)`
`Ca(HCO_(3))_(2)rarrCaO+H_(2)O+2CO_(2)`
Hence, the gas A and B are `CO_(2)` and `CO_(2)` respectively.