A compound X is carbonate of grayish metal. On heating it forms Y which is
white solid and gas Z librate which turn lime water milky . Identify X Y and Z
and write chemical reaction involved.
We know that lime water is turned milky by carbon dioxide gas. Thus, the substance Z is carbon dioxide gas. We are also given that this gas is liberated when the compound of a grayish metal is heated. Calcium has a dull grey appearance and its compound, calcium carbonate gives calcium oxide and carbon dioxide on heating. Thus, the compound X is calcium carbonate and the compound Y is calcium oxide. The gas Z is carbon dioxide. Following is the chemical equation for the reaction