What’S The Formula For Nickel Oxide?
Nickel oxide is an inorganic compound with the formula NiO. It is a black solid that is produced by heating nickel metal in the presence of oxygen. Nickel oxide is used as a material for making ceramics and in the production of materials like ferrites, in which it provides electrical conductivity. It also has applications as a catalyst and as a gas sensor.
Nickel oxide is an important material due to its use in stainless steel manufacturing. It provides the corrosion resistance that makes stainless steel such a useful metal alloy. Nickel oxide is also used to control the color and other properties in glass, and is sometimes added to improve the appearance and luster of glazes and enamels. Overall, nickel oxide has a range of applications in the metallurgy, ceramics, electronics, and chemical industries.
Chemical Formula
The chemical formula for nickel oxide is NiO. This signifies that nickel oxide contains a 1:1 ratio of nickel (Ni) atoms to oxygen (O) atoms. The formula is derived by examining the molecular structure of nickel oxide and identifying the different elements present and their relative proportions.
Breaking down the formula:
- Ni represents nickel. Nickel is a transition metal element on the periodic table with the atomic number 28.
- O represents oxygen. Oxygen is a nonmetal element on the periodic table with the atomic number 8.
Therefore, NiO indicates that for every 1 nickel atom, there is 1 oxygen atom bonded together to form the nickel oxide compound. Knowing the chemical formula allows us to determine the relative mass of the elements in nickel oxide and understand the stoichiometric relationships that govern its reactivity.
Molecular Structure
Nickel oxide has a crystalline structure with the nickel atom surrounded by six oxygen atoms in an octahedral configuration. Each nickel atom is coordinated to six oxygen atoms, while each oxygen atom is coordinated to three nickel atoms in a trigonal planar arrangement.
The nickel atoms are located at the corners of the unit cell, while the oxygen atoms are located at the face-centered positions. This gives nickel oxide a cubic close packed crystal structure with a face-centered cubic lattice.
The nickel-oxygen bonds have mostly ionic character, with some covalent character due to hybridization of the nickel orbitals. The Ni-O bonds lead to the formation of NiO6 octahedra units that are corner-sharing within the lattice.
Overall, the molecular structure of nickel oxide consists of a three-dimensional network of NiO6 octahedra with alternating nickel and oxygen atoms positioned in a highly symmetric cubic arrangement.
Properties
Nickel oxide is an inorganic compound with the chemical formula NiO. It is comprised of one nickel atom and one oxygen atom bonded together (source). Some key chemical and physical properties of nickel oxide include:
- It has a grayish black color and consists of cubic crystals (source).
- Nickel oxide is insoluble in water but soluble in hot acidic solutions (source).
- It has a melting point of 1955°C and a density of 6.67 g/cm3 (source).
- The molar mass of nickel oxide is 74.71 g/mol.
These properties make nickel oxide useful for applications like ceramics, pigments, batteries, and catalysts.
Preparation
Nickel oxide is most commonly synthesized by heating nickel compounds like nickel hydroxide, nickel nitrate, or nickel chloride to high temperatures between 350-600°C. This thermal decomposition process causes the nickel compound to break down and react with oxygen to form nickel oxide. For example, heating nickel nitrate hexahydrate (Ni(NO3)2•6H2O) results in the following reaction:
2 Ni(NO3)2•6H2O → 2 NiO + 4 NO2 + O2 + 12 H2O
Other methods used to prepare nickel oxide include precipitation reactions, sol-gel techniques, microwave irradiation, and hydrothermal methods. Nickel salts are reacted withprecipitating agents like sodium hydroxide or ammonia to produce nickel hydroxide or nickel carbonate intermediates that can then be calcined to get nickel oxide powders (https://www.mdpi.com/1996-1944/10/5/460). Sol-gel methods use nickel salt solutions that undergo hydrolysis and condensation reactions to form nickel hydroxide or nickel alkoxide gels that are also calcined. Microwave irradiation can rapidly decompose nickel precursors by dielectric heating to accelerate nickel oxide formation (https://www.sciencedirect.com/science/article/pii/S2211379718309367). Hydrothermal techniques use high temperatures and pressures in aqueous solutions in sealed vessels to produce nickel oxide nanopowders or films.
Reactions
Nickel oxide undergoes several important chemical reactions. It reacts with hydrogen at around 300 °C to produce nickel metal and water vapor (NiO + H2 → Ni + H2O). Nickel oxide can also be reduced with carbon monoxide to produce nickel metal and carbon dioxide (NiO + CO → Ni + CO2). At high temperatures, nickel oxide reacts with aluminum to form nickel metal and aluminum oxide (3NiO + 2Al → 3Ni + Al2O3). This thermite reaction is highly exothermic and produces a large amount of heat. Nickel oxide catalyzes the oxidation of carbon monoxide at ambient temperatures and is used commercially for this purpose. It also catalyzes the dehydrogenation and hydrogenation of organic compounds.
(Vakil, P. N. (2018). Nanoparticle — Electromagnetic Radiation Interaction (Doctoral dissertation, Florida State University). https://www.chem.fsu.edu/~strouse/Theses_StrouseLab/VakilThesis.pdf)
Uses
Nickel oxide has several important industrial and commercial applications. It is used extensively in the manufacturing of nickel-cadmium batteries, where it acts as the cathode material [1]. The oxide is also utilized as a catalyst in chemical processes like hydrogenation, methanation and petroleum refining [2].
Some other notable uses of nickel oxide include:
– As a green pigment and colorant in glasses, ceramics and enamels [1]
– In the production of ferrites used in transformer cores and magnetic ceramics [2]
– As an additive in porcelain glazes to impart blue, green or yellow colors [3]
– As a gas sensor material for sensing reducing gases like carbon monoxide [1]
– As an antiferromagnetic material in spintronic devices [2]
Overall, nickel oxide is a versatile inorganic compound finding extensive applications in batteries, catalysis, ceramics, magnetics and electronics due to its unique electrical, optical and magnetic properties.
Safety
Nickel oxide is considered hazardous and exposure can potentially cause negative health effects. Precautions should be taken when handling nickel oxide powder or working with processes that generate nickel oxide dust or fumes.
According to the Nickel Oxide Safety Data Sheet from Angstrom Sciences (https://www.angstromsciences.com/sites/angstrom.dev.minimalmedia.net/files/files/SDS/Nickel%20Oxide.pdf), nickel oxide is classified as a carcinogen and can cause respiratory sensitization through inhalation. It is also a skin and eye irritant. The data sheet recommends wearing protective equipment like gloves, safety goggles, and an approved respirator when handling nickel oxide.
Prolonged exposure to nickel oxide can potentially lead to pulmonary fibrosis and edema of the lungs according to the Safety Data Sheet from Buy Isotope (https://www.buyisotope.com/sds/nickel-oxide-safety-data-sheet-nickel-sds-nickel-isotope-nickel-enriched-nickel.pdf). Nickel oxide is also classified as toxic if swallowed. The data sheet states that exposure should be minimized and containment procedures utilized when working with nickel oxide.
Workplaces that generate nickel oxide should follow OSHA guidelines for permissible exposure limits and implement engineering controls, administrative controls, and personal protective equipment to minimize worker exposure.
FAQs
Here are some frequently asked questions about nickel oxide’s formula:
What is nickel oxide used for?
Nickel oxide has several important industrial applications. It is used as a catalyst in hydrogenation and dehydrogenation reactions. It is also used to make specialty glasses, in ceramics, in the production of nickel-cadmium batteries, and in some sensors and electronic components. Additionally, nickel oxide is sometimes used as a pigment.
Is nickel oxide toxic?
Nickel oxide is considered toxic if inhaled or ingested. It is classified as a potential carcinogen. Proper protective equipment like masks and gloves should be used when handling nickel oxide powder to avoid exposure. Nickel oxide is also harmful to the environment if released.
What is the chemical formula for nickel oxide?
The chemical formula for nickel oxide is NiO. It consists of one nickel (Ni) atom bonded to one oxygen (O) atom in a 1:1 ratio.
What color is nickel oxide?
Nickel oxide is usually a greenish-black powder at room temperature. However, when nickel oxide is heated, it can take on an olive-green color.
Is nickel oxide ionic or covalent?
Nickel oxide is an ionic compound. Nickel is a metal while oxygen is a nonmetal, so they form an ionic bond. The nickel atom transfers two electrons to the oxygen atom, resulting in a positively charged nickel cation (Ni2+) and a negatively charged oxide anion (O2-).
Conclusion
In summary, the key points about nickel oxide are:
- The chemical formula for nickel oxide is NiO.
- It has a cubic crystal structure with the nickel atom in an octahedral coordination.
- Nickel oxide is an antiferromagnetic material below its Neel temperature of 523 K.
- It also exhibits electrical insulation properties.
- Nickel oxide can be prepared by heating nickel in air or oxygen gas.
- It reacts with acids and is reduced to nickel metal under hydrogen gas.
- Applications include use in ceramics, glasses, catalysts, and battery cathodes.
- Nickel oxide poses health risks if inhaled and proper safety precautions should be taken when handling it.
In summary, nickel oxide is an important inorganic compound with a wide variety of uses in industry and research due to its unique chemical and physical properties.
