Is CO₂ Ionic or Covalent? 

Carbon dioxide or CO₂ is a covalent compound because it shares its electrons and forms a covalent bond. Carbon undergoes oxidation, which produces carbon dioxide (CO₂), an odourless, colourless, and incombustible gas. The two atoms that make its structure are carbon and oxygen.  CO₂ is a prominent greenhouse gas in the Earth's atmosphere and is used as refrigerant in fire extinguishers. In this article, we will study how CO₂ is a covalent compound and not an ionic compound. A bond known as a covalent bond is created when two atoms share valence electrons. Ionic compounds are those that are created through the transfer of electrons between atoms. Both atoms involved in an electron transfer become ions.

1. Why is CO₂ Covalent? According to the Pauling scale:

• The bond formed between the atoms is ionic if the difference in electronegativity between them is more than 1.7.

• The bond formed between these atoms is covalent if the difference in electronegativity between them is less than 1.7. CO

CO₂ is referred to as a covalently bonded molecule since the difference in electronegativity in the molecule is 0.89.

2. Formation of Covalent Bond in CO₂ In order to achieve a stable electronic configuration, the carbon and oxygen atoms in a CO₂ molecule share electrons to form a covalent bond. In a covalent bond within a CO₂ molecule, the electrostatic force of attraction occurs between the positive charge nuclei of the bonded atom and the negative charge electron they share which holds the carbon and oxygen atoms together. Carbon has an atomic number of 6 and an electronic configuration of 2, 4. In order to attain stability it needs 4 more electrons.

Oxygen has an atomic number of 8 and an electronic configuration of 2, 6. In order to attain stability it needs 2 more electrons.

Therefore, one atom of carbon will combine with two atoms of oxygen to attain a stable electronic configuration. To do so, carbon forms 4 covalent bonds or 2 double bonds with oxygen.

The CO₂ Lewis structure is symmetrical. The parallel lines between the C and O atoms represent the bonds. They are referred to as double bonds.

Four dots, two sticks, or lines are placed around each O, signifying the additional four electrons in the double bond of that atom. As a result, each O has an octet and is stable because it is surrounded by 8 total valence electrons. Four bonds makeup carbon, two of which are double bonds in this case. Thus, carbon has 8 valence electrons as well.

3. Molecular Geometry of CO₂ The CO₂ molecule has a linear molecular geometry. The central carbon atom (C) has no lone pairs and a double bond with two oxygen atoms (O). According to the VSEPR theory, electron pairs surrounding the central carbon atom will repel one another; as a result, the two oxygen atoms will push as far as they can to either side of the central atom, resulting in a linear structure for CO₂. Since the central atom in the CO₂ Lewis dot structure lacks a lone pair, As a result, using a bonded pair of electrons, both molecular and electron geometry predicts the shape of CO₂ as linear.

3.1 The bond angle of CO₂ The bond angle of CO₂ is 180º. The central carbon (C) atom in CO₂ has joined to two oxygen (O) atoms and lacks a lone pair. As a result, there is no distortion around the central atom, giving it a linear shape with a 180° bond angle.

4. Polarity of CO₂ Using the Pauling electronegativity chart as a generalization,

• When the difference in electronegativity is between 0.4 and 0.5, the bond is a non-polar covalent bond.

• When the difference in electronegativity is between 0.5 and 1.8 (often between 0.4 and approximately 2), the bond is referred to be polar covalent. The electronegativity value of C is 2.55 The electronegativity value of O is 3.44. The difference = 3.44 – 2.55 = 0.89. Each carbon and oxygen bond is polar covalent in nature (C=O) according to the Pauling scale. The electric dipoles, however, cancel out because CO

The electronegativity value of C is 2.55 The electronegativity value of O is 3.44. The difference = 3.44 – 2.55 = 0.89. Each carbon and oxygen bond is polar covalent in nature (C=O) according to the Pauling scale. The electric dipoles, however, cancel out because CO₂ is linear, and thus results in a net dipole of zero. It is therefore a non-polar molecule.

5. Characteristics of Carbon dioxide

• It is a non-polar substance.

• It is a trace gas that naturally exists in the atmosphere of the Earth.

• All animals, fungi, and microbes that eat living or dead plants, either directly or indirectly, produce CO₂ during respiration.

• It is an inflammable, colourless, and odourless gas that is produced when carbon is oxidized.

• It is comparatively harmless and inflammable.

• Its density is greater than that of dry air by 53%, making it heavier than air.

• It is used as a refrigerant in fire extinguishers, to control chemical processes, and to freeze food.

• The Earth's atmosphere contains the most significant amount of this greenhouse gas.

• Dry ice, a solidified form of carbon dioxide,

Key Takeaways

Key Points

• Carbon dioxide (CO₂), is one of the most important gases and has a variety of uses in a number of different industries.

• It is a covalent compound having two double covalent polar bonds.

• It is a non-polar molecule.

• The molecular and electron geometry of CO₂ is linear.

Key Terms Electronegativity: An atom's tendency to attract shared electrons (or electron density) when forming a chemical bond is known as electronegativity. The atomic number and the distance of the valence electrons from the charged nucleus have an effect on an atom's electronegativity. The higher the associated electronegativity, the more an atom or a substituent group attracts electrons.

FAQs What type of covalent bond is present in CO2? The covalent bond in CO₂ is a double bond between the carbon atom and one oxygen atom, and another double bond between the carbon atom and the other oxygen atom. Why does CO₂ have a double bond? CO₂ has a double bond because the carbon atom needs to share four electrons with the two oxygen atoms in order to complete its valence shell and become stable. Is CO2 polar or non-polar? CO₂ is a nonpolar molecule because the electrons are shared equally between the two oxygen atoms, resulting in a symmetrical distribution of charge. How does the covalent bond in CO2 contribute to its properties? The covalent bond in CO₂ contributes to its properties by making it a stable molecule, which is not easily broken apart. This stability allows CO₂ to exist as a gas at room temperature and pressure, and also makes it a relatively unreactive molecule. Is CO2 a strong or weak covalent bond? CO2 has a relatively strong covalent bond due to the involvement of a double bond between each carbon and oxygen, and the bond strength is around 105 kJ/mol.