(a) Write chemical equations.
(i) When carbon dioxide gas is passed through lime water.
(ii) When excess of carbon dioxide gas is passed through line water.
(b) List two natural forms of calcium carbonate.

Explanation

(a) (i) `Ca(OH)_(2)(aq)+CO_(2)(g)rarrCaCO_(3)(S)+H_(2)O(l)`
(ii) `Ca(OH)_(2)(aq)+CO_(2)(g)rarrCaCO_(3)(s)+H_(2)O(l)`
`CaCO_(3)(s)+H_(2)O(l)+CO_(2)(g)rarrCa(HCO_(3))_(2)(aq)`
(b) Aragonite and calcite