Is CO an ionic or a covalent substance?

What is it that is both unseen yet all around us? It’s just air. Air is made up of a variety of gases, the most abundant of which are nitrogen (78 percent) and oxygen (28 percent) (21 percent ). The remaining 1% is made up of trace gases, including highly dangerous carbon monoxide (CO).

Carbon monoxide is a gas that has no odour and is colourless. It is the most abundant air contaminant in terms of mass. It is released during the combustion of hydrocarbons in the same way that carbon dioxide (CO2) is, but it requires incomplete combustion (burning in the lack of oxygen).

Carbon monoxide’s chemistry is fascinating; its single molecule includes one carbon atom and one oxygen atom. It’s one of organic chemistry’s most studied and debated molecules.

Is carbon monoxide, on the other hand, ionic or covalent? CO is a covalent compound because it has a double covalent link and a single coordinate covalent binding between carbon and oxygen atoms (for a total of three covalent bonds). Second, due to a tiny variation in electronegativities between carbon and oxygen atoms (E=1.0), these atoms choose for electron sharing. Carbon monoxide is a covalent molecule because it forms covalent bonds when electrons are shared.

Let’s look at the many types of bonds, as well as the conditions that lead to their development and bonding in carbon monoxide.

A chemical compound’s different types

There are essentially two sorts of compounds, ionic compounds and covalent compounds, based on the interaction between different types of elements contained in a complex.

Depending on the elements present, these can be referred to as metallic compounds or coordinate compounds.

When a metal interacts with a nonmetal and creates an ionic bond by losing and gaining electrons, an ionic compound is created (transfer of electrons). NaCl, MgBr2, and AlCl3 are just a few examples.

A covalent link is created when the same types of elements interact (metal-metal, nonmetal-nonmetal, or metalloid-nonmetal), and such compounds are known as covalent compounds. CO2, NH3, H2O, and SiO2 are examples.

Do you understand why chemical bonds form? Because every atom strives for stability. Either by transferring electrons (ionic bonding) or by sharing electrons, stability can be produced (covalent bonding). An atom completes its octet and reaches the nearest noble gas configuration by chemical bonding.

Covalent Bonding is a type of bonding that occurs when two

A covalent bond is defined as a link established by the sharing of electrons between two atoms. There is no unique loss or gain of electrons in a single atom. The electrons of both atoms gain mutually, resulting in stability.

Covalent compounds are those that have a shared pair of electrons that bind the atoms of two elements together, and “bonded pair of electrons” are those that have a shared pair of electrons that link the atoms of two elements together.

Electronegativity is also a factor in determining which bonds will form. A covalent bond is established when the electronegativity difference between two elements is smaller than 2.0.

In nitric oxide (NO), for example, the electronegativity of N is 3.0 and that of O is 3.5, resulting in E = 0.5. NO is a covalent molecule since the difference is less than 2.0.

Carbon Monoxide

When one atom loses electrons and another obtains electrons, an ionic bond is established. Overall, electrons are transferred from a less electronegative element (donor) to a more electronegative element (receiver) (acceptor).

In an ionic molecule, this results in the creation of ions (cations and anions).

Only a large difference in the electronegativities of two elements allows for electron transfer. The difference must be greater than 2.0 for a compound to be ionic.

The electronegativity of Na is 0.9 while that of Cl is 3.1 in sodium chloride (NaCl). As a result of E = 2.2, sodium chloride is an ionic compound.

Bonding between ions

Carbon monoxide, commonly known as carbon oxide or carbonic oxide, is a gas that is produced by the combustion of carbon. It’s a poisonous gas with no discernible odour or colour. CO has a linear structure with sp hybridised carbon (bond angle = 180°).

When inhaled, carbon monoxide is deadly, and it is extremely combustible when in use. As a result, it is a gas that must be handled with extreme caution.

Anthropogenic sources such as the burning of fossil fuels, automotive exhaust, forest fires, and other sources produce a large portion of the gas in the atmosphere.

Carbon monoxide is created in industrial settings by burning powdered zinc with a calcium carbonate combination. The reaction of silver nitrate with iodoform can also yield it.

Apart from its toxicity and negative consequences, this gas offers a wide range of uses. It’s commonly employed as a reducing agent in the production of phosgene and aldehydes. In addition, it is employed in metallurgical processes, infrared lasers, and nickel production.

Do you have any idea? Carbon monoxide can be produced by gas stoves, house fires, furnaces, barbecues, kerosene, and gas heaters, hence smoke from these must be vented outdoors promptly.

CO Covalent Bonding (Carbon Monoxide)

Carbon monoxide molecules are made up of one carbon atom with four electrons in its outer shell and one oxygen atom with six electrons.

The electrical arrangements of carbon and oxygen at their ground states are as follows:

1s2, 2s2, 2p2 (atomic number = 6)

1s2, 2s2, 2p4 (atomic number = 8)

As can be seen, carbon requires four more electrons to complete its octet and achieve noble gas status. Oxygen, on the other hand, takes two more electrons to achieve the same result.

E = 1.0 is the difference in electronegativities between carbon (E=2.5) and oxygen (E=3.5). Because this difference is smaller than 2.0, the carbon-oxygen bond should be covalent.

Both atoms share one electron in a covalent link, and after sharing, each atom has one extra electron. The oxygen and carbon atoms each gain two extra electrons as a result of the establishment of two covalent bonds. The octet of oxygen has now been completed.

Carbon still requires two more electrons (as it wanted 4 electrons). Through the development of one coordinate covalent bond, oxygen provides one of its lone pairs to carbon.

This is a partially shared connection since only one atom contributes electrons, yet they now belong to both atoms. The octet of carbon is also completed as a result of this.

A covalent compound, unlike an ionic compound, does not produce ions (cation and anion).

Carbon Monoxide Toxicity

Carbon monoxide is hazardous to one’s health as well as the environment. This gas can react with iron in haemoglobin and convert it to carboxyhemoglobin when inhaled in significant amounts.

Because this type of haemoglobin has the lowest affinity for oxygen, it causes asphyxiation in humans. People suffocate when their vital body organs are deprived of oxygen. CO poisoning is the medical term for this.

CO poisoning is more common among mine workers and persons who live in highly polluted areas (metro cities, industrial districts).

Carbon monoxide, when released into the environment, increases the number of greenhouse gases, contributing to global warming and climate change.

Do you have any idea? Carbon monoxide is also regarded as a “silent killer” since it is undetectable, meaning you can’t tell if it’s near you or not, but when you breath it, it can silently kill you.


We studied about ionic and covalent chemical compounds, their bonding based on the type of element (metals, nonmetals, and metalloids), and the significance of electronegativity in defining the nature of bonds in this article.

We also looked at carbon monoxide and its covalent structure in depth. We discovered that between the carbon and oxygen atoms of a CO molecule, there are three covalent bonds generated through electron sharing.

We also observed how carbon monoxide, when ingested or discharged into the atmosphere, can be harmful. As a result, extreme caution must be exercised when handling it.

Good luck with your studies!

Read more: Is O2 an ionic or a covalent molecule?

Misha Khatri
Misha Khatri is an emeritus professor in the University of Notre Dame's Department of Chemistry and Biochemistry. He graduated from Northern Illinois University with a BSc in Chemistry and Mathematics and a PhD in Physical Analytical Chemistry from the University of Utah.


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