The cupric oxide, also called copper oxide (II), is a chemical compound of formula CuO. Its structure is shown in figure 1. It is found in nature as one of the components of minerals such as tenorite and paramelaconite. It is extracted from minerals from around the world, mainly in South America, in countries like Peru, Bolivia.
Some chemical compounds like ammonium carbonate and ammonia are used to promote the extraction of minerals. Cupric oxide is produced mainly by mineral extraction, however there is some process to produce it industrially.
Figure 1: structure of cupric oxide.
In industries, cupric oxide is prepared by the ignition reaction of cupric nitrate trihydrate (100-20ºC), cupric hydroxide (100ºC) or copper carbonate (250ºC):
2Cu (NO 3) 2 → 2CuO + 4NO 2 + O 2
Cu (OH) 2 (s) → CuO (s) + H 2 O (l)
CuCO 3 → CuO + CO 2
It is also prepared synthetically by heating copper metal in air to about 800 ° C.
Figure 2: appearance of tenorite (left) and paramelaconite (right)
Physical and chemical properties of cupric oxide
Copper (II) oxide occurs as a fine black powder with an ionic structure. Its appearance is shown in figure 3.
Figure 3: appearance of cupric oxide
The molecule is made up of divalent cationic copper Cu + 2 and anionic oxygen O-2. The molecules form a monoclinic crystal system, where each copper atom is coordinated by 4 oxygen atoms.
It is closely related to the other copper oxide: cuprous oxide Cu2O.
Its molecular weight is 79.545 g / mol and its density is 6.315 g / ml. Its melting point is 1326 ° C where it decomposes releasing oxygen, its boiling point is above 2000 ° C.
The compound is insoluble in water, alcohol, ammonium hydroxide, ammonium carbonate, and is soluble in ammonium chloride and potassium cyanide.
Copper oxide is amphoteric, so it can dissolve in acids and alkaline solutions. In alkaline solution, it reacts to form other copper salts:
2MetalOH + CuO + H 2 O → Metal 2
In acid solutions, it also reacts to form other copper salts:
CuO + 2HNO 3 → Cu (NO 3) 2 + H 2 O
CuO + 2HCl → CuCl 2 + H 2 O
Bursts when heated in contact with aluminum, hydrogen, or magnesium. Also, when heated, it produces some toxic fumes.
Reactivity and hazards
Copper (II) oxide is extremely poisonous and toxic if swallowed. It causes damage to the central nervous system and the endocrine system.
It is also irritating to the eyes and skin. It is not flammable, it is stable and incompatible with reducing agents, hydrogen sulfide, aluminum, alkali metals, finely powdered metals.
In case of contact with the eyes, check whether you are wearing contact lenses and remove them immediately.
Eyes should be flushed with running water for at least 15 minutes, keeping the eyelids open. Cold water can be used. Eye ointment should not be used.
If the chemical comes into contact with clothing, remove it as quickly as possible, protecting your own hands and body. Place the victim under a safety shower.
If the chemical accumulates on the victim's exposed skin, such as hands, the contaminated skin is gently and carefully washed with running water and non-abrasive soap.
Cold water can be used. If irritation persists, seek medical attention. Wash the contaminated clothing before using it again.
If the contact with the skin is severe, it should be washed with a disinfectant soap and cover the contaminated skin with an antibacterial cream.
In case of inhalation, the victim should be allowed to rest in a well-ventilated area. If inhalation is severe, the victim should be evacuated to a safe area as soon as possible.
Loosen tight clothing such as a collar, belt, or tie. If it is difficult for the victim to breathe, oxygen should be administered.
If the victim is not breathing, mouth-to-mouth resuscitation is performed. Always keeping in mind that it may be dangerous for the person providing aid to give mouth-to-mouth resuscitation when the inhaled material is toxic, infectious, or corrosive.
In case of ingestion, do not induce vomiting. Loosen tight clothing such as shirt collars, belts, or ties. If the victim is not breathing, perform mouth-to-mouth resuscitation.
In all cases, immediate medical attention should be sought.
Applications
Cupric oxide is used as a pigment for crystals, porcelain enamels, and artificial gems. Rust adds a bluish to greenish tinge to such materials. It is also used as a desulfurizing agent for petroleum gases and as an oxidation catalyst and in galvanic electrodes.
Cupric oxide is widely used in agricultural chemical and chemical industries to produce intermediate products in some processes.
It is a widely used oxidizing / reducing agent and process regulator in chemical reaction, especially in oil production.
Cupric oxide is used to produce paints and coatings and is also an ingredient in some air care products.
It is rarely used as a dietary supplement in animals, it also has application as a p-type semiconductor due to its narrow band gap. It is used as an alternative to iron oxide in termite.
Due to its fungicidal and microbicidal properties, copper (II) oxide also finds use as an insecticide and fumigant.
It is mainly used in the treatment of potato plants and as an antifouling agent on ship hulls. An antifouling agent is a material that prevents barnacles and other organisms from forming on the bottom of a boat.
When these organisms grow on the hull of a ship, they increase the friction produced when the ship passes through the water, thus reducing its speed.
The compound is also used as a wood preservative, to protect fence posts, shavings, decking, roofing, shingles, ocean walls, and other freshwater and marine structures from insects and fungi..
References
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