File:Limewater & CO2

Description
Carbon dioxide dissolves in water to form carbonic acid (H2CO3). Lime water is a solution of calcium hydroxide (Ca(OH)2). They react to form calcium carbonate (CaCO3) and water. Calcium carbonate is insoluble and forms a white precipitate. If CO2 continues to be passed,more carbonic acid forms, which then reacts with with the calcium carbonate to form calcium hydrogencarbonate, which is soluble, so the precipitate is seen to dissolve..