chemical compounds NH4 + manifests itself as a singly charged positive alkali metal cation.When interacting with anions of acidic substances are formed crystalline structure c - ammonium salts: NH4N03 nitrate, chloride NH4C1, sulfate (NH4) 2S04, which consist of the acid anion and the ammonium group.
ammonium salts obtained during the neutralization reaction, which occurs during the reaction of ammonia with an acid.
ammonium salts, such as, in principle, most of the alkali metals, can dissociate (split into cations and anions) in aqueous solution ions: ammonium salts, as alkali metal salts dissociate into ions:
NH4N03 ↔ NH4 ++ NO3-
During heating dry ammonium salts are decomposed into ammonia and acid;This process is called thermal dissociation.
The formed acid (e.g., hydrochloric acid) with NH3 evaporates and upon cooling binds with ammonia to give a salt.It should be noted that it is possible and the process is reversible decomposition:
NH3 + HCl ↔ NH4Cl
Thus, ammonia volatilized by heating, however, after some time on top of the tube again appears white coating of ammonium chloride.As a result of the formation of non-volatile acid salts, e.g., (NH4) 2S04, during heating only NH3 is volatilized, and the acid remains.This process is called irreversible decomposition.
All ammonium salts are well decomposed alkalis (when heated) with the release of ammonia:
NH4 + + OH -↔NH3 ↑ + H20
This reaction is used for the detection of mineral fertilizers with an ammonium form of nitrogen.
The interaction of ammonium carbonate with mineral and organic acids liberates carbon dioxide.The interaction sulfate or ammonium chloride with AgNO3 or BaCl formed precipitates characteristic white color.
ammonium salts: Examples
ammonium salts are widely used in agriculture.This is an excellent material for mineral dressing plants (eg, ammonium sulfate - (NH4) 2S04).It is known of nitrogen plants can absorb only in a bound form (NO3, NH4).Therefore, nitrogen compounds are very effective.Of great importance is ammonium nitrate, which contains ammonium nitrate NH4 NO3- nitrogen.
ammonium dihydrogen phosphate and hydrogen, known under the names of MAP and DAP NH4H2P04 (NH4) 2NR04 contain two chemical elements of plant nutrition - of nitrogen and phosphorus.The ammonium salts are part of the mixed fertilizers.
In the reaction of ammonia with carbon oxide (IV) was synthesized urea or urea NH2-CO-NH2.
Ammonium chloride (NH4C1) or ammonia are used in electrochemical cells, in dyeing and sittsepechatanii, tinning and soldering.Contacting with a heated metal, ammonia is decomposed into hydrogen chloride and ammonia.Hydrochloric acid reacts with the oxide, contaminating the metal surface, wherein the volatile salt is formed.
It should be noted that to the cleaned surface is very good stick solder.NH4NO3 (ammonium nitrate) together with the carbon and aluminum salts are part of the explosive - ammonal.These compounds are used in the development of rocks.Ammonium bicarbonate (NH4NSO3) is very often used in the food and confectionery industry.This compound is also used as a preservative for the different types of feeds.NH4HCO3 has denitrofitsiruyuschimi properties to accelerate ripening.
Qualitative reaction to ammonium salts.Upon heating the solution of ammonium salts formed with alkali hydroxide, ammonium hydroxide, which is cleaved with the release of ammonia.
The presence of ammonia can be judged by specific smell, as well as using colored paper indicators.For carrying out this reaction it is necessary to take 1.0 cm3 solution of ammonium salt added 0.5 cm3 solution of sodium hydroxide and heated.During the heating process, ammonia is released, produced a characteristic odor, red litmus paper turns blue.
