How does carbon dioxide react with limewater ?

When carbon dioxide (CO2) reacts with limewater, a chemical reaction occurs, resulting in the formation of a white precipitate. Limewater, also known as calcium hydroxide (Ca(OH)2) solution, is a basic solution that reacts with acidic carbon dioxide gas. The reaction can be represented by the following chemical equation:

CO2(g) + Ca(OH)2(aq) → CaCO3(s) + H2O(l)

In this reaction:

Carbon dioxide (CO2) gas is the acidic component. It is a colorless, odorless gas that is naturally present in the air and is produced during respiration, combustion, and various industrial processes.

Limewater (calcium hydroxide solution) is the basic component. It is a colorless to milky white solution that is commonly used in the laboratory to test for the presence of carbon dioxide.

Calcium carbonate (CaCO3) is the white precipitate formed as a result of the reaction. It is an insoluble solid that precipitates out of the solution as a fine white powder.

When carbon dioxide is bubbled through limewater or exposed to limewater, the limewater will turn milky due to the formation of calcium carbonate. This is a simple and common test used to detect the presence of carbon dioxide gas in a sample. The formation of the white precipitate confirms the presence of carbon dioxide.