Calcium hydroxide: properties and applications

Ca(OH)2 – calcium hydroxide (Calcium hydroxide from the Latin), it is a fairly common chemical. By nature it is considered a strong base. Melkorublenoy is a yellow powder or colorless crystals. Is able to decompose when heated, as a result stands out calcium oxide. It is poorly soluble in water. In this case an aqueous solution of calcium hydroxide in its chemical properties is an average basis. In the presence of metals can release hydrogen, which is recognized as the explosive gas.

Calcium Hydroxide when entering the body through the mouth or by inhaling an aerosol can be absorbed into the tissues and accumulate in them. At normal room temperature of 20-22 degrees this substance practically does not evaporate, but during the spraying of the particles can be dangerous to your health. Getting on the skin, in the respiratory tract or the mucous membranes of the eyes, calcium hydroxide irritating, even corrosive effects. Prolonged contact with skin may cause dermatitis. Also may be affected by lung tissue at a constant exposure of the particles of calcium hydroxide.

This chemical compound has many trivial names, such as slaked lime (it is produced by slaking calcium oxide with water), lime water (a transparent, aqueous solution). Other names: pushonka (calcium hydroxide as a dry powder ) and milk of lime (saturated aqueous suspension). Often quicklime or lime is also called calcium oxide.

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Calcium Hydroxide, whose chemical properties are considered to be aggressive towards other substances, obtained by slaking of lime, i.e., the result of the interaction (chemical reaction) of calcium oxide and water. Schematically the reaction looks like this:

CaO + H2O = Ca(OH)2

For the resulting aqueous solution of the characteristic alkaline reaction medium. Like all typical hydroxides, calcium hydroxide reacts with:

1. inorganic acids with the formation of the typical of calcium salts,

H2SO4 +Ca(OH)2 = CaSO4 + 2H2O

2. carbon dioxide that is dissolved in water, so the aqueous solution becomes cloudy very quickly in air, forming a white insoluble precipitate – the calcium carbonate

CO2 + Ca(OH)2 = CaCO3 + H2O

3. carbon monoxide with increasing temperature up to 400 Celsius degree

CO (t°) + Ca(OH)2 = CaCO3 + H2

4. salts also fall a white precipitate – calcium sulfate

Na2SO3 + Ca(OH)2 = CaSO3 + 2NaOH

The Use of calcium hydroxide is very popular. Surely, everyone knows that lime-treated walls, tree trunks, and use it as a component of construction mortar. The use of calcium hydroxide in the construction known from ancient times. And now its included in plaster it produces silicate brick and concrete, the compositions of which are almost identical with mortar. The main difference is in the method of preparation of these solutions.

Calcium Hydroxide is used to soften water hardness, for the manufacture of chloride of lime, lime inorganic fertilizers, caustification potassium carbonate and sodium. This substance also indispensable in tanning of leather in the textile industry, the production of various calcium compounds and to neutralize acid solutions and waste water including. On its basis, are organic acids.

Calcium Hydroxide has found its application in the food industry where it is known as Е526 food additive used as acidity regulator, the curing agent and thickener. In the sugar industry it is used to bessarione molasses.

In laboratory and demonstration experiments lime water is an indispensable indicator detection of carbon dioxide during the chemical reactions. Lime milk process plants in order to combat diseases and pests.