when Limewater is exposed to CO2, Calcium carbonate forms as a precipitate. if the equation for limewater going milky is Ca(OH)2+Co2=CaCo3+H20, is there an equation for when it clears? Next, use a delivery tube to pipe the contents of your sample into the boiling limewater. OC29 Investigate the density of carbon dioxide relative to air (qualitative only), and state two uses of carbon dioxide . Preparation of carbon dioxide To test for carbon dioxide, start by diluting some calcium hydroxide with water to make a limewater solution. Carbon dioxide. OC28 Carry out simple tests on carbon dioxide involving its reaction with limewater (word equation and chemical equation), and with moist litmus paper . 3 Answers. Limewater. Student Notes. So the limewater test is a better choice. This is the "classic" limewater test for carbon dioxide gas. Relevance. Then, fill up a test tube halfway with the limewater and bring it to a boil. What is the balanced chemical equation for this reaction, and what type of reaction is it? Method: Bubble gas through limewater; Observe colour change; Result: Limewater turns milky and cloudy if carbon dioxide is present; Equation: Ca(OH) 2 (aq) + CO 2 (g) → CaCO 3 (s) + H 2 O (l) *The white solid, CaCO 3, turns the limewater milky. is a solution of calcium hydroxide. Carbon dioxide reacts with calcium hydroxide solution to produce a white precipitate of calcium carbonate. ok so the test for limewater is to add carbon dioxide, it turns milky, then clear again afterwards, what's the equation for when it goes clear? A lighted wooden splint goes out in a test tube of carbon dioxide but this happens with other gases, too. When a gas is bubbled into limewater and the gas contains CO2, then the CO2 reacts with calcium hydroxide to make insoluble calcium carbonate and the solution turns milky. Carbon dioxide turns limewater milky. Answer Save. (indicate states of matter for reactants and products please) THANKS The test for Carbon Dioxide.