When a piece of limestone reacts with dilute `HCl`, a gas X is produced. When gas X is passed through lime water then a white precipitate Y is formed. On passing excess of gas X, the white precipitate dissolves forming a soluble compound Z.
(a). What are X, Y and Z?
(b). Write equations for the reactions which take place:
(i). When limestone reacts with dilute `HCl`
(ii). When gas X reacts with lime water to form white precipitate Y
(iii). When excess of gas X dissolves white precipitate Y to form a soluble compound Z.

Explanation

(a) X is carbon dioxide, Y is calcium carbonate dioxide, Y is calcium carbonate, Z is calcium hydrogencarbonate