The barium nitrate is a salt comprising an atom of barium (Ba) and nitrate ion (NO 3). It occurs as a white crystalline solid at room temperature and exists in nature as a very rare mineral known as nitrobarite. Its properties make it a toxic compound that must be handled carefully.
In fact, this compound has multiple uses in the military industry, as it can be combined with other chemical substances and added to explosives and incendiary formulations, among others.
Formula
Barium nitrate, also called barium dinitrate, has the chemical formula Ba (NO 3) 2, and it is usually manufactured by two methods.
The first of these involves the dissolution of small pieces of barium carbonate (BaCO 3) in a medium of nitric acid (HNO 3, a highly corrosive mineral acid), allowing the iron impurities to precipitate and then this mixture to be filtered, evaporated and crystallized.
The second method is carried out by combining barium chloride (BaCl 2, one of the barium salts with the highest solubility in water) with a preheated solution of sodium nitrate. This generates a reaction that results in the separation of barium nitrate crystals from the mixture.
Chemical structure
This salt presents characteristics of cubic crystalline structure or anhydrous octahedra.
Its chemical structure is as follows:
Dissociation
At elevated temperatures (592 ° C), barium nitrate decomposes to form barium oxide (BaO), nitrogen dioxide (NO 2) and oxygen (O 2), according to the following chemical reaction:
2Ba (NO 3) 2 + Heat → 2BaO + 4NO 2 + O 2
In media with high concentrations of nitric oxide (NO), the decomposition of barium nitrate produces a compound called barium nitrite (Ba (NO 2) 2), according to the following equation:
Ba (NO 3) 2 + 2NO → Ba (NO 2) 2 + 2NO 2
Reactions with soluble metal sulfates or sulfuric acid (H 2 SO 4) generate barium sulfate (BaSO 4). The vast majority of insoluble barium salts, such as carbonate (BaCO 3), oxalate (BaC 2 O 4) or metal phosphate (Ba 3 (PO4) 2), are precipitated by similar double decomposition reactions.
Applications
This substance in powder form is an oxidizing agent and reacts significantly with common reducing agents.
When this salt is mixed with other metals, such as aluminum or zinc in their finely divided forms, or with alloys such as aluminum-magnesium, it ignites and explodes on impact. For this reason, barium nitrate is considered an excellent component of weapons and explosives for military use.
Joined with trinitrotoluene (commercially known as TNT, or C 6 H 2 (NO 2) 3 CH 3) and a binder (usually paraffin wax), this salt forms a compound called Baratol, which has explosive properties. The high density of barium nitrate makes Baratol also acquire a higher density, making it more effective in its function.
Barium nitrate also binds with aluminum powder, a formula that results in the formation of flash gunpowder, which is used primarily in fireworks and theatrical pyrotechnics.
This flash gunpowder has also seen uses in flare production (such as aircraft anti-missile measures) and in stun grenades. Furthermore, this substance is highly explosive.
This salt is combined with the reactant mixture called termite to form a variation of this called termate, which generates short and very powerful flashes of very high temperatures in small areas for a short time.
Thermate-TH3 is a thermate that contains 29% composition by weight of barium nitrate, which helps to increase the thermal effect, generate flames and significantly reduce the ignition temperature of the thermate.
Termates are often used in the production of incendiary grenades and have the function of destroying tank armor and military structures.
In addition, barium nitrate was one of the most used ingredients in the production of incendiary charges used by the British in their warplanes during World War II, which they armed with incendiary munitions that were used to destroy enemy aircraft.
Finally, this salt has uses in the barium oxide manufacturing process, in the thermionic valve industry and, as already mentioned, in the creation of pyrotechnics, especially those with green colors.
Physical and chemical properties
Salt appears as a white, hygroscopic and odorless solid, which is poorly soluble in water and totally insoluble in alcohols.
It has a molar mass of 261.337 g / mol, a density of 3.24 g / cm 3 and a melting point of 592ºC. When it reaches its boiling point, it decomposes, as mentioned above. At room temperature it has a solubility in water of 10.5 g / 100 ml.
It is considered stable, but it is a strong oxidizing agent and must be kept away from combustible materials to avoid fires. It is sensitive to water and should not be mixed with acids or anhydrous.
In high concentrations (for example, containers) they must be isolated from substances that can make it react, as it can explode violently.
Like any other soluble barium compound, it is a toxic substance for animals and humans.
It should not be inhaled or consumed, as symptoms of poisoning (especially tightening of the facial muscles), vomiting, diarrhea, abdominal pain, muscle tremors, anxiety, weakness, shortness of breath, heart irregularity and seizures can occur.
Death can occur as a result of poisoning with this substance, a few hours or a few days after it occurs.
Inhalation of barium nitrate causes irritation to the respiratory mucosa and, in both modes of poisoning, solutions of sulfate salts should be prepared to apply first aid to the affected person.
In case of spills, it must be isolated from combustible substances and materials and, in cases of fire, it must never come into contact with dry chemicals or foams. The area must be flooded with water if the fire is larger.
References
- Mabus. (sf). ScienceMadness. Retrieved from sciencemadness.org
- United States Incendiary Bomb TH3-M50A3. (sf). Retrieved from ammunitionpages.com
- Cameo Chemicals. (sf). Retrieved from cameochemicals.noaa.gov
- Chemspider. (sf). Retrieved from chemspider.com