Acetic acid was added to a solid 'X' kept in a test tube. A colourless and odourless gas was evolved. The gas turned lime water milky when passed through it. Predict the nature of the solid.

Explanation

Since the gas was colourless as well as odourless and turned lime water milky, it is carbon dioxide gas. The solid 'X' which has liberated the gas on reacting with acetic acid is either a metal carbonate (e.g. `Na_(2)CO_(3)`) or some hydrogen carbonate of metal (e.g. `NaHCO_(3)`)
`Na_(2)CO_(3)(s)+2CH_(3)COOH(aq)to2CH_(3)COONa(aq)+CO_(2)(g)+H_(2)O(aq)`
`NaHCO_(3)(s)+CH_(3)COOH(aq)toCH_(3)COONa(aq)+CO_(2)(g)+H_(2)O(aq)`.