What makes lime water go cloudy

Lime water is a saturated solution of calcium hydroxide slaked lime, Ca OH 2. It is used to detect carbon dioxide CO 2 , which forms a milky white precipitate of calcium carbonate CaCO 3 when bubbled through lime water.

Excess carbon dioxide changes the calcium carbonate into calcium hydrogencarbonate calcium carbonate, Ca HCO 3 2 , which is soluble and so the white precipitate disappears.

If oxygen is present in a test tube, a glowing splint relights when it is held inside. Hydrogen ignites in air. If hydrogen is present in a test tube, a lighted splint held near its mouth ignites with a squeaky pop. Carbon dioxide reacts with calcium hydroxide solution to produce a white precipitate of calcium carbonate. Limewater is a solution of calcium hydroxide. If carbon dioxide is bubbled through limewater, the limewater turns milky or cloudy white.

Chlorine is an acidic gas that also acts as a bleach. Damp litmus paper is bleached white when it is placed in chlorine. If damp blue litmus paper is used, the paper turns red then white. Tests for gases There are several different tests to detect and identify gases and the ions in compounds. Carbon dioxide reacts with limewater to form calcium carbonate, which precipitates out of the solution.

The solution will turn milky due to the fact that calcium carbonate is a white precipitate. This reaction is actually used to test for the presence of carbon dioxide. An unknown gas is bubbled through a solution of calcium hydroxide - if the solution turns cloudy, then the unknown gas is carbon dioxide.

If you continue to bubble the carbon dioxide through the limewater another acid - base reaction occurs which results in the precipitate dissolving to give soluble calcium hydrogen carbonate:. This is how naturally ocurring acid rain is able to chemically erode limestone resulting in cave formation. When this solution evaporates the reverse reaction occurs resulting in the formation of stalactites and stalagmites.