Carbon dioxide (CO2) is nonpolar because it has a linear, symmetrical structure. The two oxygen atoms from either direction of the carbon atom pull the electron density equally from both sides. Since there’s no unequal sharing of valence electrons, CO2 is nonpolar in nature.
| Name of molecule | Carbon dioxide |
| Bond Angles | 180 degrees |
| Molecular Geometry of CO2 | Linear |
| Hybridization of CO2 | sp hybridization |
| No Valence Electrons in the molecule | 16 |
| C-O bond distance | 115 pm |
| Co2 Polar or Nonpolar? | Nonpolar |
Table of Contents
Why is CO2 nonpolar?
To answer the question of whether CO2 is polar or nonpolar, we need to understand the molecular geometry of CO2. In CO2 molecular geometry, carbon makes a double bond with each of the two oxygen atoms, resulting in a tiny symmetrical, linear molecule of CO2 that is volatile and reasonably reactive.
Because oxygen atoms make sigma bonds with the central carbon atom to complete their octet, CO2 has a linear molecule shape. As a result, lone pairs of electrons are absent, yet bonded pairs of electrons repel one another. Due to these repulsive forces between the valence shell electron pairs, the molecule acquires a linear shape.
VEs in carbon dioxide = VEs in 1 carbon atom + VEs in 2 oxygen atoms
VEs = 1(4)+2(6) = 16
Step By Step Construction of the CO2 Lewis Structure
Two oxygen atoms are placed on the terminals of the CO2 Lewis Structure, where they form bonds with the core carbon atom. Because it is the least electronegative atom in the molecule, the carbon atom is at the center.
The total carbon to oxygen atom ratio in a CO2 molecule is 1:2. On the terminals, there are two oxygen atoms that share electrons and establish bonds with the central carbon atom.
Step-1: Count the valence electrons of atoms
To draw the Lewis structure, we need to figure out the number of valence electrons in individual atoms as shown in the table.
| Atom | Electronic Configuration | Valence Electrons (VEs) |
| 8O | 1S2 2S2 2P4 | 6 |
| 12C | 1s2 2s2 2p2 | 4 |
Step-2: Determine the Central Atom
Because C is the least electronegative, it is usually positioned in the middle.
When we look at how carbon and oxygen are arranged in the periodic table, we can see that C is less electronegative than an oxygen atom. Place C is in the middle, followed by the oxygens on either side.
Step-3: Place electron pairs between the atoms
Four dots should be drawn around the carbon atom.
Draw six dots around each atom to symbolize their valence electrons by placing two oxygen atoms on both sides of the atom.
Step 4: Complete octet of the molecule
To complete the octet of the molecule, the carbon atom will donate its electrons to both oxygen atoms to form a double bond.
Molecular Geometry-Key Points
- CO2 exists in the gaseous state as linear molecules.
- The observed C-O bond distance is 115 pm.
- It has a face-centered cubic structure.
- Being linear, its dipole moment is zero.
The Properties of Carbon Dioxide
- CO2 is a nonpolar substance.
- It occurs naturally in the Earth’s atmosphere as a trace gas.
- produced during respiration by all animals, fungi, and microorganisms that depend directly or indirectly on living or decaying plants for food.
- A colorless, odorless, incombustible gas resulting from the oxidation of carbon.
- It is relatively nontoxic and noncombustible.
- It is heavier than air (53% higher density than that of dry air).
- It is used to freeze food, control chemical reactions, and as a refrigerant in fire extinguishers.
- It is the most significant greenhouse gas in the Earth’s atmosphere.
- The frozen solid form of CO2, known as dry ice,
- Ammonia reacts with CO2 under pressure to form urea, an important component of fertilizers and plastics.
Molar Mass
Molar mass of C =12.01 g/mol.
O2 molar mass = 16.00 x 2 = 32.00 g/mol.
Molar mass of CO2 = 44.01 g/mol
CO2 Lewis Structure (Key Points)
- Linear geometry ( linear triatomic molecule)
- The bond angle is 180 °C.
- The CO2 Lewis structure shows that it has no lone pairs of electrons.
- Carbon is in the central position as it is the least electronegative.
- The valence electrons of oxygen atoms are 6
- Valene electrons of carbon atom = 4
- The carbon-oxygen bond length is 116.3 pm
CO2 Formal Charge
Formal charge = valence electrons – unbonded electrons – 0.5 bonded electrons
Valence electrons in carbon = 4 electrons
Unbonded electrons in carbon = 0 electrons
Half of the bonded electrons in carbon =8/2 =4 electrons
Formal charge on carbon = 4–0–4 = 0
Valence electrons in central oxygen = 6 electrons.
Unbonded electrons in central oxygen = 4 electrons
Half of the bonded electrons in central Oxygen =4/2 =2 electrons
Formal charge on oxygen =6 – 4 – 2 =0
The formal charge on CO2 is zero, that’s why CO2 is not negative or positive.
Resonance Structure for CO2
A combination of two or more Lewis structures that together represent the delocalization of electrons in a single polyatomic ion or molecule is known as a resonance structure. Delocalized electrons that cannot be described by a single Lewis formula with an integer number of covalent bonds can be described via resonance structures.
There are three resonance structures for CO2 as shown in the figure.
Each of the structures in the diagram has 16 valence electrons and is a valid Lewis structure for carbon dioxide. In all three configurations, each atom has eight electrons surrounding it. There is, however, one that is more likely or favorable. To determine which structure is the most advantageous, we must first determine the formal charge of each structure, as illustrated in the figure below. The structure with formal charges close to zero is the most favorable Lewis structure of CO2.
Lewis Structure of CO
Quick steps to draw CO lewis structure are listed below:
- Count the valence electrons: There are 10 valence electrons.
- Decide the central atom: Central atom is Carbon as its least electronegative.
- Place electron pairs between atoms: Draw one bond line for each electron pair. Now we have eight remaining electrons.
- Complete octet: Draw two more bonds between the Oxygen and Carbon atom.
This will use four more electrons. Now we have four remaining electrons. - To complete the octets of both these atoms, place two valence electrons on both atoms.
Why is CO2 nonpolar while CO is polar?
Because of the electronegativity mismatch between C(2.55) and O(3.44) atoms, CO (Carbon monoxide) is polar.
Because the charge distributions of both atoms are uneven, the CO bond has a net dipole moment, making it a polar molecule.
CO2, on the other hand, is nonpolar due to its symmetrical linear structure.
Since there’s no unequal sharing of valence electrons in the case of carbon dioxide, it is nonpolar.
Summary
- Carbon dioxide molecules consist of a carbon atom covalently double bonded to two oxygen atoms.
- In CO2 molecules, the C-O length is 116.3 pm.
- There are three resonance structures for CO2.
- The formal charge on CO2 is zero.
- There is no lone pair of electrons in the molecule of carbon dioxide.
- Molar mass of CO2 = 44.01 g/mol
Related Links
Is HCN Polar or Nonpolar?
N2O Lewis Structure
HCN Lewis Structure
SO2 Lewis structure
SO2 Polar or Nonpolar
SiO2 Lewis Structure
CH4 Lewis Structure & Molecular Geometry
Frequently Asked Questions
Following are some of the frequently asked questions. In case you have any questions related to this blog, please feel free to comment.
1. Is Carbon dioxide acidic or basic?
Carbon dioxide is not an acid itself, since it does not contain ions of hydrogen (H+).
However, if CO2 is dissolved in water it becomes carbonic acid which is a weak acid.
2. Explain CO2 Lewis structure in simple words
In the Carbon dioxide Lewis structure, the Carbon atom is in the central position as it is the least electronegative atom in the molecule. Two Oxygen atoms are located on the terminals where both these atoms share electrons and form bonds with the central Carbon atom.
3. Does CO2 have lone pairs?
There are no lone pairs of electrons in CO2.
The lone pair of electrons are unshared valence electrons.
They are also called nonbonding pairs.
Lone pair of electrons are found in the outermost electron shell of atoms.
They can be identified by using a Lewis structure.
4. What is carbon monoxide (CO)?
Carbon monoxide (CO) is a poisonous gas that has no odor or color. There is a triple bond between the Carbon and Oxygen atoms in the CO Lewis structure. In a CO molecule, there are ten valence electrons.
5. What is a valence electron?
A valence electron is an atom’s electron that can be transferred to or shared with another atom and is found in the atom’s outermost shell.
6. What is a Carbon footprint?
According to the World Health Organization, a carbon footprint is an assessment of the human impact on the earth’s natural greenhouse. Human activities such as the burning of fossil fuels, deforestation, and land-use changes are the primary sources of carbon emissions, which result in an increase in greenhouse gas concentrations in the atmosphere. To know more, check out the article “How to Reduce Carbon footprint.”
7. Is SiCl4 polar or nonpolar?
SiCl4 (silicon tetrachloride) is a nonpolar molecule. Because the four chemical bonds between silicon and chlorine are uniformly distributed, SiCl4 is non-polar. A polar covalent bond is a type of covalent link that is intermediate between pure covalent bonds and ionic bonds. When the difference in electronegativity between the anion and the cation is between 0.4 and 1.7, such bonds occur.
Check the full article “Is SiCl4 polar or nonpolar?”.
8. Is carbon dioxide a pure substance?
Carbon dioxide is a pure substance since its composition remains constant regardless of where it is collected. Carbon dioxide is a greenhouse gas that is naturally occurring and innocuous in small amounts, but as levels grow, it can have an impact on productivity and sleep. CO2 levels concentrate inside with less ventilation since they are most typically created by the air we exhale.
Each carbon dioxide molecule will always have one carbon and two oxygens.
Check out the full article “Is carbon dioxide is a pure substance?”.
9. Is BF3 polar or nonpolar?
BF3 is a non-polar compound. In BF3, the central boron atom has sp2 hybridized orbitals, resulting in an unfilled p orbital on the Bron atom and trigonal planar molecular geometry. Because the boron-fluorine bonds are all 120 degrees apart, any net dipole in that plane is canceled out. Even if each B-F bond is polar, the net dipole moment is zero because adding the bond vectors cancels everything out.
Check the full article “Is BF3 polar or nonpolar?”.
10. What is nitrogen trifluoride gas?
Nitrogen trifluoride (NF3) is an odorless, colorless gas. When inhaled, it is exceedingly poisonous. Containers may burst violently if exposed to fire or heat for a lengthy period of time.
More Links
Author
Umair Javed
Umair has been working at Whatsinsight since 2020 as a content writer.
He has a Masters degree in Materials Science.
Please send any feedback to [email protected]
- BCl3 Lewis Structure in four simple steps - November 1, 2023
- PH3 Lewis Structure in four simple steps - October 8, 2023
- PF3 Lewis structure in four simple steps - September 24, 2023
