Carbon dioxide (CO2) lewis dot structure, molecular geometry, bond angle, hybridization, electron geometry
Carbon dioxide is made up of one carbon and two oxygen having the chemical formula CO2. It is a combustible gas resulting from the oxidation of carbon.
In this article, we will discuss Carbon dioxide (CO2) lewis structure, molecular or electron geometry, bond angle, hybridization, polar or nonpolar, etc.
At room temperature, carbon dioxide normally acts as gas but at high pressure, it turned into liquid. CO2 can be an environmental disaster due to its heat-absorbing properties.
|Name of Molecule||Carbon dioxide (CO2)|
|Molecular geometry of CO2||Linear shape|
|Electron geometry of CO2||Linear|
|Total Valence electron in CO2||16|
|Total Formal charge in CO2||0|
How to draw lewis structure of CO2 (Carbon dioxide)?
CO2 Lewis structure is made up of one carbon (C) atom, and two oxygen (O) atoms. The carbon (C) atom is kept at the central position and the Oxygen (O) atom is on either side of it in the lewis diagram. In the CO2 lewis structure, there are a total of 4 lone pairs present.
A lewis structure helps us to know how electrons are arranged around individual atoms in a molecule.
Let’s see how to draw the lewis dot structure for CO2 with simple steps.
Follow some steps for drawing the Lewis dot structure for CO2
1. Count total valence electron in CO2
As we know, the lewis diagram is all about representing the valence electron of atoms within the molecule. Valence electrons are the outermost electron of an atom that can participate in the bond formation either by donating or accepting.
To find the total valence electron in CO2, look at the periodic group of carbon and oxygen atoms.
By looking at the periodic table, we come to know carbon belongs to 14 groups and oxygen belongs to the 16th group in the periodic table. Hence, carbon has 4 valence electrons and oxygen has 6 valence electrons.
⇒ Valence electron of Oxygen = 6 [∴ Periodic group of oxygen = 16 or 6A]
⇒ Valence electron of Carbon = 4 [∴ Periodic group of carbon = 14 or 4A]
∴ Total valence electron available for drawing the CO2 lewis structure = 4 + 2*6 = 16 valence electrons [∴ CO2 molecule has one carbon and two oxygen atoms]
2. Find the least electronegative atom and placed it at center
Now we need to find which atom(Carbon or oxygen) has the least electronegativity then place that atom to the center in lewis’s diagram.
The electronegativity of the oxygen atom is 3.44 and for the carbon atom, it is 2.55
Clearly, the Carbon atom is less electronegative than Oxygen, therefore, place it at the center in the lewis diagram and put the oxygen atoms on either side of it.
3. Connect carbon and oxygen with a single bond
In the third step, we will start to draw the lewis structure of CO2 by connecting the outer atom (Oxygen) to the central atom (Carbon) with the help of a single bond.
By looking at the above diagram, we come to know that two single bonds are used that contain 4 electrons. (A single bond means 2 electrons)
So, we used 4 electrons from a total of 16 valence electrons that are available for drawing the Lewis structure of CO2.
∴ (16 – 4) = 12 valence electrons
Now we are left with 12 valence electrons.
4. Placed remaining valence electrons around the outer atom
As we are left with 12 valence electrons and we have to place these electrons around the outer atom(Oxygen) first to complete its octet rule.
“Octet rule show that atom is most stable when eight electrons present in its valence shell.”
So, oxygen needs 8 electrons around it for coming into the stable zone. Therefore, place the remaining valence electron around oxygen first for completing its octet shell.
So, look at the above diagram and see how many valence electrons we used till now and how many are left. Each oxygen has 8 electrons(6 dot electrons + 2 electrons in a single bond), therefore, oxygen atoms completed their octets comfortably.
In the above diagram, 16 valence electrons are used(6 on each oxygen atom + 4 electrons in form of two single bonds).
So, we are left with zero valence electrons.
5. Complete central atom octet and make covalent bond if necessary
Now, this is the final step for completing the CO2 lewis dot structure. In this step, we have to complete the central atom(Carbon) octet for its stability.
As carbon needs 8 electrons to complete its octet shell but carbon has only 4 electrons(two single bonds) around it. (Look at 4th step structure).
therefore, the carbon atom needs 4 more electrons to complete its octet.
Also, we have no extra valence electrons left for completing the octet of carbon. So, to overcome this problem, we will take the help of oxygen lone pair electrons.
We will convert the one lone pair of each oxygen atom into a covalent bond.
Now look at the above structure and see if the atoms of the CO2 molecule, completed their octet or not.
The carbon central atom has 8 electrons in its valence shell, since, it connected with 2 double bonds. [∴ 1 double bond means 4 electrons].
Also, both oxygen also has 8 electrons, as they are connected with one double bond means 4 electrons + 4 electrons represented as dots.
Yes, both atoms(Carbon and oxygen) have completed their octet rule comfortably as each of them has 8 electrons in the outermost shell.
Now just check the stability of the above structure with the help of the formal charge concept.
6. Check the stability with the help of a formal charge concept
“The lesser the formal charge on atoms, the better is the stability of the lewis structure.”
To calculate the formal charge on an atom. Use the formula given below-
We will calculate the formal charge for the 5th step structure.
For carbon atom:
⇒ Valence electrons of carbon = 4
⇒ Nonbonding electrons on carbon = 0
⇒ Bonding electrons around carbon (two double bonds) = 8
∴ (4 – 0 – 8/2) = 0 formal charge on the central carbon atom.
For oxygen atom
⇒ Valence electrons of oxygen = 6
⇒ Nonbonding electrons on oxygen = 4
⇒ Bonding electrons around oxygen (one double bond) = 4
∴ (6 – 4 – 4/2) = 0 formal charge on the oxygen atom.
So, both atoms(carbon and oxygen) get a formal charge equal to zero.
Carbon dioxide (CO2) lewis structure
Therefore, the above lewis structure of CO2 is better, appropriate, and most stable as the overall formal charge is zero.
What is the electron and molecular geometry of CO2 (Carbon dioxide)?
The molecular geometry of CO2 is Linear. It has a linear geometry arrangement like O=C=O. CO2 has 2 electron domains, resulting in a linear electron domain geometry. Electron geometry considers lone pairs as well bond pairs while determining the geometry of the molecule.
CO2 molecular geometry or shape
Molecular geometry is an arrangement of atoms in a molecule. CO2 lewis structure can give us an approximate measure of its molecular shape but to determine the precise molecular geometry of CO2, we need to look at the VSEPR theory.
VSEPR theory predicts the shape of the molecule by taking the measure of repulsion between electron pairs in the valence shell.
Now the question arises why the molecular geometry or shape of CO2 is linear?
The molecular geometry of CO2 is linear. The central atom carbon (C) is bonded with two oxygen (O) atoms via a double bond and it has zero lone pair. Based on VSEPR theory, electrons pairs around the central carbon atom are going to repel each other, so, those two oxygen atoms are going to push far as much as they can to either side of the central atom and that makes, CO2 is a linear molecule.
As you see in the above figure, the bond pair on both sides of the carbon central atom are repelling each other, because of this, both side oxygen atoms are pushed far away from each other in a straight line, therefore, the overall molecular geometry of CO2 will be linear.
VSEPR theory only predict the geometry based on electron pair that are around the Central atom.
It doesn’t matter how many lone pair are on outer atoms, only thing is matter around the central atom.
So, in a CO2 molecule, the carbon central atom has no lone pair, and it is attached with only bonding pairs, hence, for keeping the repulsive force least generated by the bonding pairs around the central atom, CO2 acquires the linear molecular geometry or shape.
The electron geometry for CO2 is also linear. Since, the central Carbon (C) atom is surrounded by 2 regions of electron density, according to VSEPR theory, “the maximum distance two regions of electron density can get away from affords a geometry called Linear”.
We can also find the electron and molecular geometry of CO2 using the AXN method and VSEPR chart.
AXN is a simple formula that represents the number of the bonded atom and lone pair on the central atom to predict the shape of the molecule using the VSEPR chart.
According to AXN method-
- A represents the central atom.
- X represents the bonded pair of electrons to the central atom.
- N represents the lone pair of electrons on the central atom
AXN notation for CO2 molecule:
- A denotes the central atom, so, carbon is the central atom in CO2 molecule A = Carbon
- X denotes the bonded atoms to the central atom, Carbon is bonded with two oxygen atoms. Therefore, X = 2
- N represents the lone pair on the central atom, as per the CO2 lewis structure, the carbon central atom has zero lone pair. Hence, N = 0
So, the AXN generic formula for the CO2 molecule becomes AX2N0 or AX2.
According to the VSEPR chart, if any molecule has the AX2 formula then the molecule geometry of that molecule is linear and electron geometry is also linear.
Look at the VSEPR chart below to clear your doubts.
So, the molecular geometry or shape of the CO2 is linear and its electron geometry is also linear.
Hybridization of CO2
“Hybridization is a theory that helps us understand the shape of molecular orbitals upon bonding to compounds”
According to the VSEPR theory, a Steric number is used to determine the hybridization of an atom.
When the Steric number is equal to 2, then the hybridization of that atom is sp, and if it is equal to 3 then Sp²…..so on.
Note: Steric number = Hybridization number
The steric number is simply an addition of bonded atom to the atom and a lone pair present on that atom.
The formula for finding the steric number of atoms.
According to CO2 lewis’s structure, Carbon is the central atom that has zero lone pair on it and two Oxygen atoms are attached to it.
Therefore, Steric number = 2 + 0
∴ S.N. = 2
So, two steric number means carbon has Sp hybridization in the CO2 molecule.
You can also find the steric number of the Oxygen atom. Each oxygen in the lewis dot structure of CO2 has two lone pairs on it and is attached to 1 Carbon atom.
Steric number of Oxygen = 1 + 2
= 3 is the steric number, which means each oxygen has Sp² hybridization in the CO2 molecule.
The bond angle of CO2
CO2 has a bond angle of 180º. In CO2, the carbon (C) central atom has no lone pair and is attached to two oxygen (O) atoms. Therefore, no distortion occurs around the central atom which makes it linear in shape that has a bond angle of 180º.
Carbon dioxide polarity: Is CO2 polar or nonpolar?
Well, we know the polar molecule has some dipole moment because of unequal distribution of charges whereas the non-polar molecule has an equal distribution of charges that cause zero dipole moment because they cancel out each other due to the symmetrical shape of the molecule.
Is Carbon dioxide (CO2) polar or non-polar? CO2 is a non-polar molecule because it contains two bonds(C=O) that are arranged symmetrically. Due to this, dipole moment generated on both sides along C=O cancels out each other making it’s a non-polar molecule.
Let’s understand whether carbon dioxide is polar or non-polar in detail.
Three factors that indicate the polarity of CO2
It directly influences the polarity nature of any atom or molecule. Because the polarity is directly proportional to the difference of electronegativity created by atoms or molecules. Electronegativity means the tendency of an atom to attract electrons towards itself.
If the electronegativity difference between the atoms is high then the polarity will also be higher. Now, look at the electronegativity of carbon and oxygen.
As carbon electronegativity is around 2.6 and for oxygen, it is around 3.45. Therefore, oxygen has a higher tendency to attract an electron to itself than carbon.
Also, the electronegativity difference between carbon and oxygen is more than 0.5, and according to the Pauling scale if the electronegativity difference between atoms is higher than 0.5 then the bond between that atoms behaves as polar.
But it doesn’t necessary if some bond is polar then the whole molecule can also be polar. In the case of CO2, the C=O bond is polar in nature due to the difference in electronegativity between them. But the whole molecule of CO2 is non-polar in nature.
2. Dipole moment
Dipole moment ensures the strength of polarity between carbon and oxygen atom. As greater the dipole moment of the molecule, the more is the polar nature of that molecule. The electronegativity difference between the atoms(Carbon and oxygen) induced positive and negative charges.
As oxygen is more electronegative than carbon, hence, some negative charge is induced around oxygen and a partial positive charge is induced around carbon. So, these charges create two dipole moments around the C=O bond. Let’s see the figure given below.
As dipole moment induced in the direction from carbon to oxygen. Because oxygen is more electronegative than carbon so it attracts electrons towards itself. But dipole moments generated in between the atoms can easily be canceled out each other because the CO2 has linear molecular geometry that is highly symmetrical.
In mathematical terms, we can express dipole moment as D = Q×R
Dipole moment formula = charge on the atoms * the distance between them.
3. Geometrical or molecular shape:
The geometrical structure of any molecule has great influences on the polarity nature. As the CO2 molecular geometry is linear that has two polar covalent bonds (C=O) but they are in the opposite direction. Also, a central atom of CO2 doesn’t contain any lone pair which makes its molecule shape highly symmetric.
So, the C=O bond is highly symmetric and opposite in direction which can easily be canceled out each other causing this molecule to become non-polar in nature.
All these explanations are enough to Know – Is CO2 polar or nonpolar?
How many lone pairs are present in the lewis structure of CO2?
Lone pairs are those represented as dots in the lewis diagram that do not take part in the formation of bonds and are also called nonbonding electrons.
By looking at the lewis structure of CO2, we see there are 8 dot electrons are present(4 dot electrons on each oxygen), which means, a total of 4 lone pairs are present in the lewis structure of CO2. [∴ 2 dot electrons means 1 lone pair].
How many valence electrons are available for drawing the CO2 lewis dot structure?
⇒ Valence electron available for Carbon = 4
⇒ Valence electron available for Oxygen = 6
∴ Total Valence electron available for CO2 lewis dot structure = 4 + 2×6 = 16 electrons
Why CO2 is non-polar?
CO2 is non-polar because of its symmetrical geometry and the dipole moment generated along with the C=O bond also canceled out each other as the molecular shape of CO2 is linear and it has Sp hybridization with a bond angle of 180º which makes it a highly symmetrical molecule.
Also, no lone pair is present on the central atom in the CO2 lewis structure which helps to avoid distortions in the molecule.
Why the molecular geometry of CO2 is linear?
The molecular geometry of CO2 is linear. Because the carbon (C) central atom has no lone pair and is attached to the two oxygen (O) atoms. So, there are two regions of electron density around the carbon central atom, based on VSEPR theory, it will acquire linear molecular geometry.
The electron pair around the carbon central atom will repel each other and tried to go far from each other, they will take the position where repulsion becomes minimum between them.
According to the VSEPR theory, the central atom with two regions of electron density adopts a linear molecular geometry because repulsion is minimum in electron pairs at this position.
Hence, the molecular geometry or shape of CO2 appears linear.
Why electron and molecular geometry of CO2 are same?
Two types of geometry can be predicted with the help of VSEPR theory- (a). Electron geometry (b). Molecular geometry
Electron geometry considers all electrons(Bonding and Lone pair electrons) whereas molecular geometry considers only Bonding atoms to determine the geometry of any molecule.
As we know, the molecular geometry of CO2 is linear and electron geometry is also linear.
Since there is no lone pair present on the central atom in the CO2 lewis dot structure. Therefore, both molecular and electrons geometry predict the shape of CO2 with the help of bonded pair of electrons.
Hence, the molecular geometry and electron geometry of CO2 is the same.
- OF2 lewis structure and its molecular geometry
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- ClO2-- lewis structure and its molecular geometry
- CH2O lewis structure and its molecular geometry
- CH3COOH lewis structure and its molecular geometry
- C2H4 Lewis structure and its molecular geometry
- H2S lewis structure and its molecular geometry
- SF2 lewis structure and its molecular geometry
Uses of Carbon dioxide
- It is used as a fire extinguisher gas.
- It is used as an inert gas in welding.
- It can be used to freeze the food and to control the chemical reaction.
- It is used for various purposes like as a solvent, an anesthetic, an antagonist, etc.
- It is used as dry ice to cool things.
- It is used to increase the speed of hardening the concrete.
- It is used to make fizzy drinks.
- CO2 is used for chemical production, petroleum production, agriculture practices, etc.
- Carbon dioxide is used to carbonate sodas.
- It is used as a feedstock for the synthesis of chemicals and fuels.
Useful properties of Carbon dioxide
- It is heavier than air.
- It is soluble in water.
- In high concentrations, its odor becomes acidic.
- It has a molar mass of 44.009 g·mol−1.
- The melting point of CO2 is −56.6 °C.
- Relatively it is nontoxic and noncombustible.
- CO2 can make bubbles in soft drinks.
- Carbon dioxide turns lime water into milky.
- CO2 is normally present in our blood at a normal range but a large dose of it is very toxic to the human body or other living organisms.
How Carbon dioxide is produced?
- It is produced by burning fossil fuels.
- Except for pure hydrogen, burning anything which has carbon in it like wood, plastic, gasoline, coal, etc. emits Co2.
- It can be produced by the respiration of plants and animals.
- The volcanic eruption produced Carbon dioxide.
- The decomposition of organic matter produced CO2 and various other gases like methane.
- CO2 is exhaled from our body because it is the waste product that is absorbed in our blood.
Preparation of Carbon dioxide
(a). In laboratory preparation, CO2 is produced by reacting dilute acid with metallic carbonate.
⇒ CaCO3 + 2HCl → CaCl2 + CO2 + H2O
(b). By thermal decomposition of limestone at a temperature around 850ºC.
⇒ CaCO3 → CaO + CO2
(c). Combustion of carbon-based fuel. Example( methane reacting with oxygen).
⇒ CH4 + 2O2 → CO2 + 2H2O
(d). It is produced with the help of the fermentation of sugar.
⇒ C6H12O6 + 6O2 → 6CO2 + 6H2O
Finally after a long discussion about the CO2 lewis structure, molecular geometry, bond angle, hybridization, etc. We are going to take the last overview of this article with the help of some important points.
- The total valence electron available for drawing the CO2 lewis structure is 16.
- The molecular geometry of CO2 is linear.
- The electron geometry of CO2 is also linear.
- In the CO2 lewis structure, there is a total of 4 lone pairs present. Two lone pairs on each oxygen atom.
- The bond angle of CO2 is 180º. Since it is linear in shape with an arrangement like that O=C=O.
- Two types of hybridization in CO2 – Sp, and Sp2.
- The net dipole moment of CO2 is zero.
- CO2 is a non-polar molecule.
- The overall formal charge in CO2 is zero.