NH3 is one of the most famous and useful chemicals. It has found wide application in the agricultural industry and not only. It has unique chemical properties due to which it is used in various industries.
What is NH3?
The name of the substance NH 3 is known even to the person furthest from chemistry. This is ammonia. Ammonia (NH 3 ) is otherwise called hydrogen nitride and, under normal conditions, is a colorless gas with a distinct odor characteristic of a given substance. It is also worth noting that NH 3 gas (called ammonia) is almost two times lighter than air!
In addition to gas, it can be a liquid at a temperature of about 70 ° C or exist in the form of a solution (ammonia solution). A distinctive feature of liquid NH 3 is the ability to dissolve the metals of the main subgroups of groups I and II of the table of elements of D. I. Mendeleev (that is, alkaline and alkaline earth metals), as well as magnesium, aluminum, europium, and ytterbium. Unlike water, liquid ammonia does not interact with the above elements, but acts precisely as a solvent. This property allows metals to be isolated in their original form by evaporation of the solvent (NH 3 ). In the figure below, you can see how the sodium dissolved in liquid ammonia looks.
What does ammonia look like in terms of chemical bonds?
The scheme of ammonia (NH 3 ) and its spatial structure is most clearly shown by a triangular pyramid. The top of the “pyramid” of ammonia is a nitrogen atom (highlighted in blue), as can be seen in the image below.
The atoms in a substance called ammonia (NH 3 ) are linked by hydrogen bonds, just like in a water molecule. But it is very important to remember that bonds in the ammonia molecule are weaker than in the water molecule. This explains that the melting and boiling points of NH 3 are lower when compared with H 2 O.
Chemical properties
The most common are 2 methods for producing an NH 3 substance called ammonia. In industry, the so-called Haber process is used, the essence of which is the binding of air nitrogen and hydrogen (obtained from methane) by passing a mixture of these gases at high pressure over a heated catalyst.
In laboratories, ammonia synthesis is most often based on the interaction of concentrated ammonium chloride with solid sodium hydroxide.
We proceed to a direct examination of the chemical properties of NH 3.
1) NH 3 acts as a weak base. That is why the following equation describes the interaction with water:
NH 3 + H 2 O = NH4 + + OH -
2) Also based on the basic properties of NH 3 is its ability to react with acids and form the corresponding ammonium salts:
NH3 + HNO 3 = NH 4 NO 3 (ammonium nitrate)
3) Earlier it was said that a certain group of metals dissolves in liquid ammonia. However, some metals are also able not only to dissolve, but to form compounds with NH 3 under the name of amides:
Na (tv) + NH3 (g) = NaNH 2 + H 2
Na (tv) + NH3 (g) = NaNH 2 + H 2 (the reaction is carried out in the presence of iron as a catalyst)
4) The interaction of NH 3 with metals Fe 3+ , Cr 3+ , Al 3+ , Sn 4+ , Sn 2+ results in the formation of the corresponding metal hydroxides and ammonium cation:
Fe 3+ + NH 3 + H 2 O = Fe (OH) 3 + NH 4 +
5) The result of the interaction of NH 3 with metals Cu 2+ , Ni 2+, Co 2+ , Pd 2+ , Pt 2+ , Pt 4+ is most often the corresponding metal complexes:
Cu 2+ + NH 3 + H 2 O = Cu (OH) 2 + NH 4 +
Cu (OH) 2 + NH 3 = [Cu (NH 3 ) 4 ] 2 + + OH -
The formation and further path of NH3 in the human body
It is well known that amino acids are an integral part of biochemical processes in the human body. They are the main source of NH 3, a substance called ammonia, the result of their oxidative deamination (most often). Unfortunately, ammonia is toxic to the human body, the ammonium cation (NH 4 + ) mentioned above, which accumulates in the cells, is easily formed from it. Subsequently, the most important biochemical cycles slow down, and as a result, the level of ATP produced decreases.
It is easy to guess that the body needs mechanisms to bind and neutralize the released NH 3 . The diagram below shows the sources and some products of ammonia binding in the human body.
So, in short, the neutralization of ammonia occurs through the formation of its transport forms in tissues (for example, glutamine and alanine), by excretion with urine, through the biosynthesis of urea, which is the main natural way of neutralizing NH 3 in the human body.
NH3 - a substance called ammonia
In modern times, liquid ammonia is the most concentrated and cheapest nitrogen fertilizer that is used in agriculture for the ammonization of rough soils and peat. When liquid ammonia is introduced into the soil, the number of microorganisms grows, but there are no negative consequences, such as, for example, from solid fertilizers. The figure below shows one of the possible installations for liquefying gaseous ammonia using liquid nitrogen.
Evaporating, liquid ammonia absorbs a lot of heat from the environment and causes cooling. This property is used in refrigeration units to produce artificial ice when storing perishable food products. In addition, with its help, the soil is frozen during the construction of underground structures. Aqueous solutions of ammonia are used in the chemical industry (it is an industrial non-aqueous solvent), laboratory practice (for example, as a solvent in the electrochemical production of chemical products), medicine and household appliances.