Copper nitrate: quantitative and qualitative characteristics

The term "nitrate" in chemistry means the salt of all known nitric acid, which contains a negatively charged portion of NO3. In mineralogy and agriculture, another designation of nitrates - "saltpetre" - is used very often, but even here this name is gradually replaced by scientifically more justified.

Considering the basic chemical properties of nitrates, it is worth noting in the first place that they are formed during the interaction of nitric acid with oxides, salts and, more often, with metals. In conditions of room temperature, almost all nitrates have high stability, but when the temperature rises to 200-6000 ° C, they begin to melt, gradually decomposing into constituent elements.

By the way, by what elements the nitrates decompose, one can judge what place they have in the electrochemical series of metal stresses. In particular, all nitrates that, when decomposed, give nitrites and oxygen molecules contain metals that are to the left of magnesium (for example, lithium, barium, aluminum, cobalt). The same nitrates, which, decomposing, form oxides of nitrogen and metal, as well as oxygen are located in the electrochemical series in the interval from magnesium to copper.

Copper nitrate behaves in a special way: when decomposed, oxygen is not released, but divalent copper oxide and nitrogen dioxide are formed. And, for example, a solution of silver nitrate, decomposing at a temperature of "only" 1700 ° C, gives off not only pure oxygen with tetravalent nitrogen oxide, but also directly the silver molecules.

It is also worth noting that absolutely all nitrates are the strongest oxidants, and it is in the solid state. But in solution they lose their oxidizing properties, differing, therefore, from the same nitric acid.

Already from ancient times people have noticed that salts of nitric acid and, first of all, nitrates are excellent fertilizers, which have the ability to restore the fertility of the soil. Later, a significant part of nitrates was used to create explosives and drugs.

A special role among all nitrates belongs to copper nitrate.

Copper nitrate (Cu (NO3) 2) is a complex inorganic substance that is structurally and chemically related to copper and nitric acid salts. According to its physical properties, copper nitrate is a solid with a crystal lattice, which dissolves perfectly in water and a number of other solutions (for example, in ethanol, ammonia liquid, ethyl acetate). At the same time, like a number of other nitric acid salts, copper nitrate absorbs moisture well, forming specific dark-blue crystals that spread out in air with high relative humidity.

The chemical properties of this nitrate are related, on the one hand, to the fact that the molar mass of copper is a constant value of 64 g / mol, and on the other hand, to the ability of copper nitrate to absorb moisture, thereby changing its name (nitrate trihydrate - Hexahydrate), and its properties. For example, anhydrous copper hydrate decomposes at a temperature of 1700 ° C, and trihydrate - at 1200 ° C.

The molar mass of copper is also important in the fact that the main way to produce anhydrous copper nitrate is to synthesize molecules of copper and tetravalent copper oxide. It should be borne in mind that copper nitrate is a fairly toxic substance, so both its production and storage should be carried out in accordance with all the basic requirements of safety regulations. In particular, it is necessary to be careful not to get this substance on the mucous membranes or on the human skin, as in this case there is irritation, which can cause various diseases.

By the way, almost all nitrates cause some or other lesions of the skin. For example, the same solution of silver nitrate in contact with human skin causes the appearance of black spots, and if you hold it long enough, it can result in a burn.