Question

What is the difference between quick line and lime water and what happens when excess CO2 is added to lime water?

Answer 1

Quicklime is a caustic compound known by its chemical name calcium oxide (CaO)

Limewater is the common name for a diluted solution of calcium hydroxide. Calcium hydroxide, Ca(OH)2, is sparsely soluble in water (1.5 g/L at 25 °C). Pure limewater is clear and colorless, with a slight earthy smell and an alkaline bitter taste of calcium hydroxide.

When we add Lime water and excess carbon dioxide The following reaction takes place:

Ca(OH)2 + CO2(g)--->CaCO3(s) + H2O(l)
where the Ca(OH)2 is lime-water. The CaCO3 precipitate causes the milkiness. If you pass excess CO2 through lime-water, the CaCO3 reacts with the excess CO2 and water to form calcium hydrogen carbonate or calcium bicarbonate.