What happens when carbon dioxide is passed through lime water for some time, and then for a long time? Explain with balanced chemical reactions.

Question

Accepted Answer

When passed for some time, carbon dioxide reacts with calcium hydroxide (lime water) to form insoluble calcium carbonate, which turns the lime water milky white: Ca(OH)2(aq) + CO2(g) → CaCO3(s) + H2O(l). When carbon dioxide is passed for a long time, the calcium carbonate further reacts to form soluble calcium bicarbonate, and the milky white colour disappears: CaCO3(s) + H2O(l) + CO2(g) → Ca(HCO3)2(aq).