Ammonium Nitrate Formula (NH4NO3) - TRUNG TÂM GIA SƯ TÂM TÀI ĐỨC

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What is Ammonium Nitrate?

Ammonium nitrate is an ionic salt made up of the ammonium cation (NH₄)⁺ and the nitrate anion (NO₃)^–. The chemical formula of this compound is NH₄NO₃.

Since Ammonium Nitrate contains half of the nitrogen (N) in the nitrate form and half in the ammonium form, ammonium nitrate is a widely used fertiliser. The nitrate form is easily transported to the roots with the help of soil moisture and is thus instantly available for plant absorption.

Structure of Ammonium Nitrate

This compound features an ionic bond between an ammonium ion and a nitrate ion. The structure of an NH4NO3 molecule is illustrated below.

The pi electrons in the nitrate ion are delocalized due to resonance. The net charge on this ion is -1 (since the nitrogen atom holds a charge of +1 and each oxygen atom holds a charge of -⅔). Therefore, only one NH4+ ion can form an ionic bond with one NO3– ion.

Chemical Data

Chemical Formula	NH₄NO₃
Molar Mass/ Molecular Weight	80.043 grams per mole
Density	1.725 grams per cubic centimetre
Melting Point	442.8K (169.6^oC)
Boiling Point	Decomposes at 483K (210^oC)

Preparation of Ammonium Nitrate

Ammonium nitrate readily dissolves in water by dissociating into its constituent ions. This salt is acidic in nature since it is derived from a weak base (NH3) and a strong acid (HNO3).

NH₄NO₃ can be prepared from the acid-base reaction between nitric acid and ammonia, described by the following chemical equation:

NH₃ + HNO₃ → NH₄NO₃

This reaction is highly exothermic and proceeds violently. Ammonium nitrate is also known for its oxidizing powers. It is widely used in many explosives used in the mining and construction sectors. NH₄NO₃ is also one of the key components of ANFO, one of the most popular choices of industrial explosives.

Ammonium Nitrate Properties

Physical Properties

Ammonium nitrate is a crystalline solid having a white/grey colour.
It has a trigonal crystal structure.
It is quite soluble in water; its solubility at 20^oC is 150g/100ml. The solubility increases to 1024g/100ml when the temperature is raised to 100o
The dissolution of NH₄NO₃ in H₂O is highly endothermic.
This compound has very low shock and friction sensitivities.

Chemical Properties

When NH₄NO₃ is reacted with the hydroxides of alkali metals, the nitrates of alkali metals are formed along with ammonia.
Upon heating, this compound decomposes to form nitrous oxide (N₂O) and water.
When exploded, this compound yields N₂, O₂, and water as the byproducts.
Despite being a component of many explosives, ammonium nitrate is not an explosive by itself. It must be mixed with a primary explosive such as an azide to form an explosive mixture.

Ammonium Nitrate as Fertilizer

Since nitrogen is an essential component of both the NH₄ (ammonium) and NO3 (nitrate) components of the molecule, ammonium nitrate is a widely used fertiliser. In addition to plants being able to absorb nitrogen directly from the molecule in its nitrate form, soil microorganisms can also progressively change the ammonium part of the complex into nitrate. Due to these advantages, ammonium nitrate is a preferred nitrate source for plant nutrition by many vegetable farmers. Ammonium nitrate is used by animal farmers for fertilising pasture and hay since urea-based fertilisers have a tendency to volatilize from the soil before the plants can absorb them. Additionally, it is very soluble, making it a good choice for irrigation systems.

Uses of Ammonium Nitrate

Some important applications of this ionic salt are listed below.

NH4NO3 is a key component of many fertilizers since it is quite rich in nitrogen (34%).
Another advantage of this compound is that it doesn’t lose its nitrogen to the atmosphere, as is the case with urea.
When mixed with fuel oil, it forms an explosive known as ANFO, which is one of the most popular industrial explosives.
The dissolution of this compound in water is quite endothermic, making it an ideal choice of material in instant cold packs.
It is also used in the mining and construction industry as a component of explosives.

Despite its numerous applications, the use of this compound is being slowly phased out by the governments of many countries due to its scope for misuse. Ammonium nitrate was one of the key ingredients of the explosives that were used in the 2011 Delhi bombings and the 2013 blasts in Hyderabad.

Frequently Asked Questions – FAQs

What is ammonium nitrate used for?

Used to make fertilizers and explosives, and as a nutrient in antibiotic and yeast growth. Ammonium nitrate is the nitric acid ammonium salt. It has a function as a fertilizer, an oxidizing agent and an explosive.

Is ammonium nitrate a base or acid?

Ammonium nitrate is not acid but a salt but the solution is acidic since it is a salt with a weak base (ammonium hydroxide) and a heavy nitric acid.

What happens when you mix water and ammonium nitrate?

It feels cold when ammonium nitrate is dissolved in water which indicates an endothermic reaction. In an endothermic reaction, the ammonium nitrate dissolves in water, a chemical reaction that absorbs heat rather than releases it. Ammonium nitrate consists of tightly packed, ionic bonds.

What can you do with ammonium nitrate?

Ammonium nitrate is a chemical compound used as a fertilizer in agriculture, for producing pyrotechnics, as an ingredient in cold packs, and for scientific demonstrations. This is also used in mining and quarrying to produce controlled explosions.

Is ammonium nitrate a good fertilizer?

Ammonium nitrate fertilizer is the compound’s most common application but it also has a very volatile quality, making it useful in some industries. The use of ammonium nitrate in gardens and large-scale growing fields stimulates plant growth and provides a ready source of nitrogen that plants can draw from.

Why is ammonium nitrate NH4NO3

Because NH4 is ammonium. It is a compound, not just nitrogen and hydrogen. NO3 is nitrate, a compound, not just nitrogen and oxygen. NH4NO3 is “ammonium nitrate”, a compound of NH4 and NO3 together.

Is NH4NO3 a base or acid?

acid

Answer and Explanation:

NH4NO3 is an acid. Its pH is around 5.4. If a substance has a pH lower than 7, it is an acid.

Why ammonium nitrate is banned?

* A large quantity of ammonium nitrate exposed to intense heat can trigger an explosion. Storing the chemical near large fuel tanks, in bulk in large quantities and in a poorly-ventilated facility could cause a massive blast. The larger the quantity, the more risk it will detonate.

Is NH4NO3 strong or weak?

NH4NO3 is a salt of weak base and strong acid. So it will undergo cationic hydrolysis and its aqueous solution will be acidic in nature.

Is ammonium nitrate a strong or weak acid?

acidic salt

Ammonium nitrate is an acidic salt as it’s solution is acidic because of it being a salt of weak base(ammonium hydroxide) and strong acid(nitric acid).

What countries banned ammonium nitrate?

Several countries have banned the sale of ammonium nitrate as a fertilizer, including Australia, mainland China, Germany, Ireland, the Netherlands, and Turkey.

How toxic is ammonium nitrate?

It is known that chronic ingestion of 6 to 12 grams/day of ammonium nitrate may cause gastritis, acidosis, isosmotic diuresis, and nitrite toxicity manifesting as methemoglobinemia or vasodilatation.

Can ammonium nitrate explode alone?

While in its pure form, ammonium nitrate is stable, heat and confinement or a severe shock can lead to detonation – which history has shown, can be disastrous. For example, in a fire, molten ammonium nitrate may become confined (e.g. in drains or machinery) and it could explode if it becomes contaminated.

What happens when you mix ammonium nitrate and water?

Ammonium nitrate dissolves in water and dissociates in ammonium cation and nitrate anion. These then combine with the free hydroxyl anions and hydrogen cations of water to form ammonium hydroxide and nitric acid.

How powerful is ammonium nitrate?

However, ammonium nitrate also has the power to devastate, being four times more powerful than gun powder and with an explosion efficiency of approximately 40% that of TNT . In its pure form, ammonium nitrate is stable, but heat, confinement, contamination, and shock can lead to fire and detonation.

Who invented ammonium nitrate?

chemist Fritz Haber

Synthetic ammonium nitrate (NH4NO3) was invented in 1909 by Polish-German chemist Fritz Haber, who was awarded the 1918 Nobel Prize in Chemistry for his work on the Haber-Bosch Process (the production of synthetic ammonia from nitrogen and hydrogen).