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Limewater is the common name for a diluted solution of calcium hydroxide. Calcium hydroxide, Ca(OH)2, is sparsely soluble in water (1.5 g/L at 25 °C〔´Solubility of Inorganic and Metalorganic Compounds - A Compilation of Solubility Data from the Periodical Literature´, A. Seidell, W. F. Linke, Van Nostrand (Publisher), 1953〕). Pure limewater is clear and colourless, with a slight earthy smell and an alkaline bitter taste of calcium hydroxide. The term lime refers to the alkaline mineral, and is unrelated to the acidic fruit. Limewater is prepared by stirring calcium hydroxide in pure water, and filtering off the excess undissolved Ca(OH)2. When excess calcium hydroxide is added to limewater, a suspension of calcium hydroxide particles results, giving it a milky aspect, in which case it has the common name of milk of lime. Milk of lime or a saturated solution of lime (limewater) has a pH of 12.3. It is basic in nature. ==Chemistry== Carbon dioxide passed into limewater gives a milky solution. This is due to the insoluble suspension of calcium carbonate formed: : Ca(OH)2''(aq)'' + CO2''(g)'' → CaCO3''(s)'' + H2O''(l)'' If excess CO2 is added, the following reaction takes place: : CaCO3''(s)'' + H2O''(l)'' + CO2''(g)'' → Ca(HCO3)2''(aq)'' The milkiness disappears since calcium bicarbonate is water-soluble. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Limewater」の詳細全文を読む スポンサード リンク
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