GIPHOTOSTOCK / SCIENCE PHOTO LIBRARY GIPHOTOSTOCK / SCIENCE PHOTO LIBRARY
Calcium oxide reacts with water. A small amount of calcium oxide (CaO, quicklime) in a test tube is mixed with water. Calcium hydroxide (Ca(OH)2, hydrated lime or caustic lime or slaked lime) is produced in the exothermic reaction: CaO + H2O -> Ca(OH)2. This process is known as slaking. Calcium hydroxide is poorly soluble in water. It still produces enough hydroxide ions to turn phenolphthalein indicator pink, indicating an alkaline resulting solution.
Model release not required. Property release not required.