Science class 7

why does lime water turn milky when we blow air into it

1 Like

get result from books

Visit : CBSE CLASS 7

The chemical formula for lime water is Ca(OH)2.

We breathe out carbon dioxide. The chemical formula for carbon dioxide is CO2.

So, when we blow air into lime water, the carbon dioxide present in the air we blow out reacts with the lime water to form calcium carbonate and water. The chemical formula for calcium carbonate is CaCO3. Calcium carbonate is white in colour which turns the water milky.


Ca(OH)2 + CO2 → CaCO3 + H2O

(Lime Water + Carbon Dioxide → Calcium Carbonate + Water)