Why does the milkiness disappear when CO2 is added in lime water for a long time?

Answer 1

When you first start to bubble carbon dioxide through limewater (calcium hydroxide solution), they react and form calcium carbonate. This isn't very soluble, so you see it as a mist of fine particles of chalk, which we describe as 'the limewater has gone cloudy/ milky'. As you continue to bubble, carbon dioxide dissolves in the water to form carbonic acid, which dissolves the calcium carbonate, so the milkiness disappears. Here are the reactions: Ca(OH)2 + CO2 --> CaCO3 + H2O forming the milkiness 2H2CO3 + CaCO3 --> Ca(HCO3)2 + H2O +CO2 removing the milkiness again This second reaction is the same one as for rainwater flowing over limestone rocks.

Answer 2

The milkiness in limewater is due to the calcium carbonate precipitate in the water. As excess CO2 is passed through limewater, the calcium carbonate is turned into calcium bicarbonate, which is clear.

Answer 3

Lime water turns milky when it comes in contact with carbon dioxide.

Lime water is Ca(OH)2 and it reacts with carbon dioxide to form calcium carbonate

which is white in colour and makes the solution milky.

Reaction:

Ca(OH)2 + CO2 ---------> CaCO3 + H2O

Answer 4

Lime water is essentially calcium hydroxide, Ca(OH)2. The reaction with CO2 (carbon dioxide) is...
Ca(OH)2 + CO2 ==> CaCO3 + H2O and CaCO3 is not soluble in water so it will be cloudy or milky.

Answer 5

limewater turn milky on passing CO2 due to the formation of calcium carbonate which is formed after reacting CO2 with lime water.

Answer 6

A precipitate of calcium carbonate is formed.