The ammonium hydroxide is a compound with the molecular formula NH4Oh oh5NO produced by the dissolution of ammonia gas (NH3) in water. For this reason, it is called ammonia water or liquid ammonia..
It is a colorless liquid with a very intense and sharp odor, which is not isolatable. These characteristics have a direct relationship with the concentration of NH3 dissolved in water; concentration that in fact, being a gas, can encompass huge amounts of it dissolved in a small volume of water.
A considerably small part of these aqueous solutions is composed of NH cations.4+ and the OH anions-. On the other hand, in very dilute solutions or in frozen solids at very low temperatures, ammonia can be found in the form of hydrates, such as: NH3∙ HtwoOr, 2NH3∙ HtwoO and NH3∙ 2HtwoOR.
As a curious fact, Jupiter's clouds are made up of dilute solutions of ammonium hydroxide. However, the Galileo space probe failed to find water in the planet's clouds, which would be expected due to the knowledge we have of the formation of ammonium hydroxide; that is, they are NH crystals4OH totally anhydrous.
The ammonium ion (NH4+) is produced in the renal tubular lumen by the union of ammonia and hydrogen, secreted by the renal tubular cells. Likewise, ammonia is produced in renal tubular cells in the process of transformation of glutamine to glutamate, and in turn, in the conversion of glutamate to α-ketoglutarate.
Ammonia is produced industrially by the Haber-Bosch method, in which nitrogen and hydrogen gases are reacted; using ferric ion, aluminum oxide and potassium oxide as catalysts. The reaction is carried out at high pressures (150 - 300 atmospheres) and high temperatures (400 -500 ºC), with a yield of 10 -20%.
Ammonia is produced in the reaction, which when oxidizes produces nitrites and nitrates. These are essential in obtaining nitric acid and fertilizers such as ammonium nitrate..
Article index
As its definition indicates, ammonium hydroxide consists of an aqueous solution of ammonia gas. Therefore, within the liquid, there is no defined structure other than that of a random arrangement of NH ions.4+ and OH- solvated by water molecules.
Ammonium and hydroxyl ions are products of a hydrolysis equilibrium in ammonia, so it is common for these solutions to have a pungent odor:
NH3(g) + HtwoO (l) <=> NH4+(ac) + OH-(ac)
According to the chemical equation, a high decrease in the water concentration would shift the equilibrium to the formation of more ammonia; that is, as the ammonium hydroxide is heated, ammonia vapors will be released.
For this reason, NH ions4+ and OH- fail to form a crystal under terrestrial conditions, which results in the solid base NH4Oh don't exist.
Said solid should be composed only of electrostatically interacting ions (as can be seen in the image).
However, under temperatures well below 0ºC, and surrounded by enormous pressures, such as those prevailing in the cores of icy moons, ammonia and water freeze. In doing so, they crystallize into a solid mixture with various stoichiometric ratios, the simplest being NH3∙ HtwoO: ammonia monohydrate.
NH3∙ HtwoO and NH3∙ 2HtwoOr they are ammonia ice, since the solid consists of a crystalline arrangement of water and ammonia molecules linked by hydrogen bonds..
Given a change in T and P, according to computational studies that simulate all the physical variables and their effects on these ices, a transition of an NH phase occurs.3∙ nHtwoOr to an NH phase4Oh.
Therefore, only under these extreme conditions does NH4OH can exist as a product of a protonation within ice between NH3 and the HtwoOR:
NH3(s) + HtwoYou) <=> NH4Oh s)
Note that this time, unlike ammonia hydrolysis, the species involved are in a solid phase. An ammonia ice that turns salty without the release of ammonia.
NH4Oh oh5NOT
35.046 g / mol
It is a colorless liquid.
Up to about 30% (for NH ions4+ and OH-).
Very strong and sharp.
Acre.
34 ppm for nonspecific detection.
38 ºC (25%).
Exists only in aqueous solution.
Miscible in unlimited proportions.
0.90 g / cm3 at 25 ºC.
Relative to air taken as unity: 0.6. That is, it is less dense than air. However, logically the reported value refers to ammonia as a gas, not its aqueous solutions or NH4Oh.
2,160 mmHg at 25 ºC.
It is capable of dissolving zinc and copper.
11.6 (1N solution); 11.1 (solution 0.1 N) and 10.6 (0.01 N solution).
pKb = 4.767; Kb = 1.71 x 10-5 at 20 ºC
pKb = 4.751; Kb = 1,774 x 10-5 at 25ºC.
Increasing the temperature almost imperceptibly increases the basicity of ammonium hydroxide.
What are all the common and official names that NH receives?4OH? According to what is established by the IUPAC, its name is ammonium hydroxide because it contains the hydroxyl anion.
Ammonium, due to its +1 charge, is monovalent, so using the Stock nomenclature it is named as: ammonium hydroxide (I).
Although the use of the term ammonium hydroxide is technically incorrect, since the compound is not isolatable (at least not on Earth, as explained in detail in the first section).
Also, ammonium hydroxide is called ammonia water and liquid ammonia..
NH4OH as it does not exist as a salt in terrestrial conditions, it cannot be estimated how soluble it is in different solvents.
However, it would be expected to be extremely soluble in water, since its dissolution would release enormous amounts of NH3. Theoretically, it would be an amazing way to store and transport ammonia.
In other solvents capable of accepting hydrogen bonds, such as alcohols and amines, it could be expected that it would also be very soluble in them. Here the NH cation4+ is a hydrogen bond donor, and OH- acts as both.
Examples of these interactions with methanol would be: H3N+-H - OHCH3 and HO- - HOCH3 (OHCH3 indicates that the oxygen receives the hydrogen bond, not that the methyl group is linked to the H).
-In contact with the eyes it causes irritation that can lead to eye damage..
-It is corrosive. Therefore, on contact with the skin it can cause irritation and at high concentrations of the reagent, it causes skin burns. Repeated contact of ammonium hydroxide with the skin can cause it to be dry, itchy and red (dermatitis)..
-Inhalation of ammonium hydroxide mist can cause acute irritation of the respiratory tract, characterized by suffocation, coughing, or shortness of breath. Prolonged or repeated exposure to the substance can result in recurrent bronchial infections. Also, inhalation of ammonium hydroxide can cause irritation of the lungs..
-Exposure to high concentrations of ammonium hydroxide could constitute a medical emergency as fluid build-up in the lungs (pulmonary edema) can occur..
-The concentration of 25 ppm has been taken as an exposure limit, in an 8-hour work shift, in an environment where the worker is exposed to the harmful action of ammonium hydroxide.
-In addition to the potential harm to health from exposure to ammonium hydroxide, there are other precautions that must be taken into account when working with the substance..
-Ammonium hydroxide can react with many metals, such as: silver, copper, lead, and zinc. It also reacts with the salts of these metals to form explosive compounds and release hydrogen gas; which in turn, is flammable and explosive.
-It can react violently with strong acids, for example: hydrochloric acid, sulfuric acid and nitric acid. It also reacts in the same way with dimethyl sulfate and halogens..
-Reacts with strong bases, such as sodium hydroxide and potassium hydroxide, producing ammonia gas. This can be verified by observing the equilibrium in solution, in which the addition of OH ions- shifts equilibrium to NH formation3.
-Copper and aluminum metals, as well as other galvanized metals, should not be used when handling ammonium hydroxide, due to its corrosive action on them..
-It is used as an additive in many foods in which it acts as a leavening agent, pH control and finishing agent for the surface of foods..
-The list of foods in which ammonium hydroxide is used is extensive and includes baked goods, cheeses, chocolates, candies, and puddings..
-Ammonium hydroxide is listed as a safe substance by the FDA for food processing, as long as established standards are followed..
-In meat products it is used as an antimicrobial agent, being able to eliminate bacteria such as E. coli, reducing it to undetectable levels. The bacteria are found in the intestines of cattle, adapting to the acidic environment. Ammonium hydroxide, by regulating the pH, hinders bacterial growth.
-Ammonium hydroxide has several therapeutic uses, including:
-The 10% solution is used as a stimulant of the respiratory reflex
-Externally it is used on the skin to treat insect bites and bites -It acts in the digestive system as an antacid and carminative, that is, it helps to eliminate gases.
In addition, it is used as a topical rubefacient for acute and chronic musculoskeletal pain. As a consequence of the rubefacient action of ammonium hydroxide, there is a local increase in blood flow, redness and irritation..
-It works to reduce NOx (highly reactive gases such as nitric oxide (NO) and nitrogen dioxide (NOtwo)) for battery emissions and NOx reduction in stack emissions.
-It is used as a plasticizer; paint additive and for surface treatment.
-Increases the porosity of the hair allowing the pigments of the dye to have a greater penetration, which achieves a better finish.
-Ammonium hydroxide is used as an antimicrobial agent in wastewater treatment. In addition, it is involved in the synthesis of chloramine. This substance fulfills a function similar to chlorine in the purification of swimming pool water, having the advantage of being less toxic.
-It is used as a corrosion inhibitor in the petroleum refining process.
-It is used as a cleaning agent in various industrial and commercial products, being used on various surfaces, including: stainless steel, porcelain, glass and oven.
-Additionally, it is used in the production of detergents, soaps, pharmaceuticals and inks..
Although it is not administered directly as a fertilizer, ammonium hydroxide fulfills this function. Ammonia is produced from atmospheric nitrogen by the Haber-Bosch method and is transported refrigerated below its boiling point (-33 ºC) to the places of use.
The pressurized ammonia is injected, as vapor, into the soil where it immediately reacts with the edaphic water and passes into the form of ammonium (NH4+), which is retained in the cation exchange sites of the soil. In addition, ammonium hydroxide is produced. These compounds are a source of nitrogen.
Along with phosphorus and potassium, nitrogen constitutes the triad of main plant nutrients essential for their growth..
Yet No Comments