Kalkkiliemi

Kalkkiliemi, also known as calcium hydroxide solution or limewater, is an aqueous solution of calcium hydroxide (Ca(OH)2). It is typically prepared by adding calcium hydroxide, a white powder, to water and allowing the undissolved solid to settle. The clear liquid that remains is limewater.

Limewater is a mild base and has a slightly alkaline pH. Historically, it has been used in various applications. One notable use is in testing for the presence of carbon dioxide gas. When carbon dioxide is bubbled through limewater, it reacts to form insoluble calcium carbonate, causing the solution to turn cloudy or milky. This reaction is a common demonstration in chemistry education.

In agriculture, limewater has been used as a soil amendment to reduce acidity and improve soil structure. It can also be used as a component in whitewash, a traditional interior and exterior coating. In some food preparations, particularly in certain cultures, it serves as a pickling agent or a neutralizing agent. The clarity and purity of limewater can be important depending on its intended application. Contamination can affect its effectiveness and safety.