Question

Why lime water turns milky with carbon dioxide but becomes clear with excess carbon dioxide?

Answer 1

So the solution turns milky. When we pass excess CO2,calcium bicarbonate Can(HCO3) formed which is soluble in water ,so the solution turns transparent. When CO2 is passed through lime water insoluble precipitate CaCO3.

Answer 2

Lime water turns milky with Carbon dioxide when passed over it due to the formation of insoluble CaCO3 (Calium Carbonate).

Ca(OH)2 + CO2 gives CaCO3 + H2O
(insoluble calcium
carbonate)

But becomes clear due to the formation of soluable Calcium bicarbonate(Calcium Hydrogen Carbonate).
CaCO3 + CO2 + H2O gives Ca(HCO3)2
(soluble calcium
bicarbonate)