The calcium oxide. Physical, thermal and chemical properties. Application.

Calcium Oxide – the crystalline compound of white color. Other names for this substance-quicklime, calcium oxide, “terabit”, “quicklime". Calcium oxide, the formula of which is CaO, and a product of interaction of (H2O) water – Ca(OH)2 (“pushonka”, or slaked lime) has found wide application in the construction business.

How to get calcium oxide?

1. Industrial method of obtaining this substance is to heat (due to temperature) the decomposition of limestone (calcium carbonate):

CaCO3 (limestone) = CaO (calcium oxide) + CO2 (carbon dioxide)

2. Calcium oxide can be obtained by the interaction of simple substances:

2Ca (calcium) + O2 (oxygen) = 2CaO (calcium oxide)

3. The third method of obtaining calcium oxide is the thermal decomposition of calcium hydroxide (Ca(OH)2) and calcium salts of several oxygen-containing acids:

2Ca(NO3)2 (calcium nitrate) = 2CaO (resulting substance) + 4NO2 (nitric oxide) + O2 (oxygen)

Physical properties of calcium oxide

1. Appearance: crystalline compound of white color. Kristallizuetsya the type of sodium chloride (NaCl) face-centered cubic crystal lattice.

2. Molar mass is 55,07 grams/mole.

3. Density is 3.3 grams/cm³.

Thermal properties of calcium oxide

1. The melting point is equal 2570 degrees

2. Boiling point is 2850 degrees

3. Molar heat capacity (at standard conditions) is equal 42.06 j/(mol·K)

4. Enthalpy of formation (standard conditions) is -635 kJ/mol

Chemical properties of calcium oxide

Calcium Oxide (formula CaO) – this is a basic oxide. So it can:

– dissolve in water (H2O) with the release of energy. This forms calcium hydroxide. This reaction looks like this:

CaO (calcium oxide) + H2O (water) = Ca(OH)2 (calcium hydroxide) + of 63.7 kJ/mol;

– can react with acids and acidic oxides. In this form the salt. Here are examples of responses:

CaO (calcium oxide) + SO2 (sulfur dioxide) = CaSO3 (calcium sulfite)

CaO (calcium oxide) + 2HCl (hydrochloric acid) = CaCl2 (calcium chloride) + H2O (water).

Application of calcium oxide:

1. The main volumes of the substances used in the manufacture of silica brick in the construction. Previously, quicklime, used as calcareous cement. It received when it was mixed with water (H2O). As a result, the calcium oxide was converted to hydroxide, which is then absorbing from the atmosphere the carbon dioxide (CO2), strongly hardened, turning into calcium carbonate (CaCO3). Despite the cheapness of this method, at present, the calcareous cement is almost never used in construction, since it has good ability to absorb and accumulate fluid.

2. As a refractory material calcium oxide is suitable as an inexpensive and available material. Fused calcium oxide has resistance to water (H2O), which allowed it to be used as a refractory where the use of expensive materials is impractical.

3. Laboratories use higher calcium oxide for drying those substances that do not react.

4. In the food industry this product is registered as food additive under the designation E 529. Used as emulsifier to produce a homogeneous mixture of immiscible substances among themselves – water, oil and grease.

Recommended

"Knowledge is light and ignorance is darkness": the value, meaning and alternatives

There are some sayings that would seem to need no explanation, such as “teaching & ndash; light and ignorance – darkness”. But some still do not understand their meaning. But not only for such people is written by our article. I...

What was invented by Mendeleev for the army. The history and fate of the invention

D. I. Mendeleev was a brilliant Russian scientist-polymath, who made many important discoveries in various fields of science and technology. Many people know that he is the author of “Fundamentals of chemistry" and the periodic law of chem...

The origin of the Slavs. The influence of different cultures

Slavs (under this name), according to some researchers, appeared in the story only in 6 century ad. However, the language of nationality bears the archaic features of the Indo-European community. This, in turn, suggests that the origin of the Slavs h...

5. In industry calcium oxide used to remove sulfur dioxide (SO2) from the flue gases. Used, as a rule, 15% solution of water. The reaction, which interact with hydrated lime and sulfur dioxide, it turns out gypsum CaCO4 and CaCO3. In experiments, scientists have achieved in 98% of cleaning up the smoke of sulfur dioxide.

6. Used in the special “samokleyushcheysya” ware. Capacity with a small amount of calcium oxide is placed between two vessel walls. When perforation of the capsule in water, the reaction begins with the release of a certain amount of heat.