Slaked Lime is Calcium Hydroxide [also known as Lime Water] Lime Water is used to detect the presence of Carbon Dioxide: Ca(OH)2(aq) + CO2(g) → CaCO3(s) + H2O(l) Calcium Carbonate [Chalk: CaCO3] is insoluble in water and so is deposited as a precipitate upon completion of the reaction: The Lime Water turns 'chalky'
Take a small quantity of quicklime (CaO) in a beaker and add a small quantity of water into it. Quicklime reacts vigorously with water to form a suspension of slaked lime (Ca(OH)2) in water. CaO + H2O = Ca(OH)2 Then leave the beaker containing slaked lime undisturbed for some time. After some time a clear solution is obtained as the suspension of slaked lime settles down. This clear solution is called lime water. Then take…
Lime water is a solution of water and Ca(OH)2. When you blow air into the lime water, you are blowing CO2 gas into it, and it undergoes a series of reactions that result in the precipitate calcium carbonate (CaCO3), which makes the water look milky. The overall reaction is Ca(OH)2(aq) + CO2(g) ---> CaCO3(s) + H2O(l) .
If carbon-dioxide is passed into lime water turns milky with excess of carbon-dioxide the milkiness disappears give reason?
Lime water is actually Ca(OH)2 . When it reacts with CO2 insoluble CaCO3 is formed which turns solution milky. When excess CO2 is added CaCO3 reacts with water and CO2 to form Calcium bicarbonate which is soluble. That is why the solution clears out. Equations: 1) Ca(OH)2 + CO2 --------> CaCO3 + H2O 2) CaCO3 + CO2 + H2O ---------> Ca(HCO3)2