How to draw CO2 Lewis Structure? - Science Education and Tutorials

Q: What is the CO2 Lewis structure?

CO2 Lewis structure is dot representation

Q: What is the formal charge on the CO2 Lewis structure?

Zero charges on the CO2 molecular structure

The carbon dioxide chemical formula is CO2. Drawing CO2 Lewis Structure is very easy to by using the following method. Here in this post, we described step by step method to construct CO2 Lewis Structure. The oxygen and carbon elements come as the member of the oxygen and carbon family groups from the periodic table respectively. The valence electrons in oxygen and carbon are six and one respectively. Carbon dioxide is used as a nonpolar gas molecule. It is essential for photosynthesis in plants.

Table of Contents

Key Points To Consider When Drawing The CO2 Electron Dot Structure

A three-step approach for drawing the CO2 Lewis structure can be used. The first step is to sketch the Lewis structure of the CO2 molecule, to add valence electrons around the carbon atom; the second step is to add valence electrons to the two oxygen atoms, and the final step is to combine the step1 and step2 to get the CO2 Lewis Structure.

The CO2 Lewis structure is a diagram that illustrates the number of valence electrons and bond electron pairs in the CO2 molecule. The geometry of the CO2 molecule can then be predicted using the Valence Shell Electron Pair Repulsion Theory (VSEPR Theory), which states that molecules will choose the CO2 geometrical shape in which the electrons have from one another.

Finally, you must add their bond polarities to compute the strength of the two C-O double bonds (dipole moment properties of the CO2 molecule). The oxygen-carbon bonds in carbon dioxide(CO2), for example, are non-polarised toward electronegative oxygen in CO2 molecule, and because both bonds have the same size and are located around two oxygen terminals of the linear-shaped with two lone pairs (in total four electrons) on each oxygen atoms, their sum of dipole moment is zero due to the CO2 molecule’s bond dipole moment and high electron polarity to the oxygen atoms. Because each two C-O bonds polarity canceled each other in the CO2 molecule due to the linear geometry of the CO2 molecule. The carbon dioxide(CO2) molecule is classified as a nonpolar molecule.

The molecule of carbon dioxide (with linear molecular geometry) is tilted, the bond angles between oxygen and carbon are 180 degrees. It has a difference in electronegativity values between oxygen and carbon atoms, with central carbon’s pull being less than two-terminal oxygen’s in the CO2 molecule. But they canceled each other due to the symmetrical linear structure with two lone pairs in the two oxygen atoms in the molecular geometry of the CO2 molecule.

As a result, it has the zero dipole moment. The CO2 molecule has a zero dipole moment due to an equal charge distribution of negative and positive charges. But both oxygen and carbon atoms fall on the oxygen and carbon family groups in the periodic table respectively. The oxygen atom is a lightly higher electronegative value than carbon in the CO2 molecule. The CO2 molecule has the net dipole moment of 0D value in the ground state energy level.

CO2 molecule has two C-O double bonds. Its dipole moment in the ground state is totally different as compared with the excited state. If it absorbs light may be from visible or UV light. It undergoes pi to pi star and n to pi star transition from ground state energy level to excited state energy level. In the excited state energy level, the CO2 molecule shows a definite dipole moment. But it is very dynamic in nature.

Molecules can be classified as polar or nonpolar. The molecule polar behaves in a different manner as compared to nonpolar.

Overview: CO2 Lewis Structure

The central atom is carbon, which is bordered on two terminals with oxygen atoms( in linear geometry), and no lone pairs on the central carbon atom in the linear molecular geometry. Carbon has four outermost valence electrons, indicating that it possesses four electrons in its outermost shell, whereas oxygen has six valence electrons in its outermost shell. To complete the octet of the oxygen atom requires two valence electrons on each of their outermost shell.

Two oxygen atoms establish covalent connections with the central carbon atom as a result, leaving the carbon atom with no lone pairs. There are no lone pairs of electrons on the carbon central atom that resists the bond pairs of the two C-O bonds. According to VSEPR theory, the single C-O bond pairs polarity leads the CO2 molecule to take on the linear geometry structure.

The CO2 molecule’s two C-O bonds are arranged in symmetrical polarity order around the linear molecular geometry, giving rise to the CO2 molecular shape. The CO2 molecule has a linear molecular geometry because there is no electrical repulsion between the lone pairs of electrons in oxygen and two double bond pairs(C-O) of the CO2 molecule.

Lewis structure of CO2 has dot electron representative structure. Valence electrons of atoms undergo orbitals mixing in the chemical reactions, gives new types of molecular species of CO2. The molecule is nothing but a bundle of valence electrons from the atoms. But it is converted to bond pairs and lone pairs in the molecular structure.

Electronegative value Difference Calculation of CO2 Molecule:

Oxygen and carbon Electronegative difference in CO2:

The oxygen atom has an electronegativity of 3.44, while carbon has an electronegativity of 2.55 in the CO2 molecule. The difference in electronegativity of oxygen and carbon can be estimated using the method below.

The electronegative value difference between oxygen and carbon in CO2 molecule
Electronegativity value of oxygen = 3.44
Electronegativity value of carbon= 2.55
Difference of electronegativity value between oxygen and carbon in CO2 molecule = 3.44 – 2.55 = 0.89
Electronegativity difference between C-O bond calculation of CO2 molecule

The electronegative difference between oxygen and carbon is greater than 0.5. This indicated the bond polarity moves near to polar nature. C-O bond polarity in the CO2 molecule is polar.

Because of this difference in electronegativity of oxygen and carbon atoms, the CO2 molecule’s C-O bonds become nonpolar. The total net dipole moment of the CO2 molecule is zero due to the cancellation of the bond dipole moment in the linear geometry due to the presence of no lone pairs of electrons in the central carbon atom. The electronegativity of an atom is the strength with which it may attract bound electron pairs to its side. The polarity of CO2 is discussed in our previous post.

As a result, the C-O bond’s dipole moment is less due to the low polarization of the bonds and no lone pairs of electrons on carbon, and all C-O bonds’ dipoles are arranged in the symmetrical CO2 molecular geometry. The CO2 molecule has a zero net dipole moment.

The electron dot structure of the CO2 molecule is also known as the CO2 Lewis structure. It determines the number of outermost valence electrons as well as the electrons engaged in the CO2 molecule’s bond formation. The outermost valence electrons of the CO2 molecule must be understood while constructing the Lewis structure of the molecule.

The carbon atom is the middle element in CO2 molecular geometry, with four electrons in its outermost valence electron shell, whereas the oxygen atom has six electrons in its outermost valence electron shell. The oxygen atom has six valence electrons.

The CO2 has a total of 16 valence electrons as a result of the foregoing above-said reasoning. With the core central carbon atom, the two terminals with two oxygen atoms form covalent bonds, leaving the carbon atom with no lone pairs in the middle of linear molecular geometry.

Because two lone pairs on each terminal oxygen atom create interaction with C-O bond pairs(but it is negligible in the ground state of the CO2 molecule). The bond angle of the O=C=O bond in the linear molecular geometry is approximately 180 degrees. This angle is greater than the CH4 molecule bond angle. The C-O bond length is 116pm(picometer).

To sketch the CO2 Lewis structure by following these instructions:

Step-1: CO2 Lewis dot Structure by counting valence electrons on the carbon atom

To calculate the valence electron of each atom in CO2, look for its periodic group from the periodic table. The oxygen and carbon group families, which are the 16th and 14th groups in the periodic table, are both made up of oxygen and carbon atoms respectively. In their outermost shells, carbon and oxygen have four and six valence electrons respectively.

Calculate the total number of valence electrons in the CO2 molecule’s outermost valence shell. The first step is to determine how many electrons are in the CO2 Lewis structure’s outermost valence shell. An electron in an atom’s outermost shell is known as a valence electron. It is represented by dots in the CO2 Lewis diagram. The CO2 molecule’s core carbon atom can be represented as follows:

Total outermost valence shell electron of oxygen atom in CO2= 6
Total outermost valence shell electron of carbon atom in CO2= 4
The CO2 molecule has one central carbon and two oxygen atoms. Then the total outermost valence shell electrons can be calculated as follows
∴ Total outermost valence shell electrons available for CO2 Lewis structure( dot structure) = 4+2*6= 16 valence electrons in CO2.
calculation of total valence electron of CO2 molecule

Choose the atom with the least electronegative value atom and insert it in the center of the molecular geometry of CO2. We’ll choose the least electronegative value atom in the CO2 molecule to place in the center of the CO2 Lewis structure diagram in this phase.

But in this case, carbon is slightly less electronegative than oxygen. So that carbon stays in the central molecular structure. The electronegativity value in periodic groups grows from left to right in the periodic table and drops from top to bottom.

The first step is to put four valence electrons around the carbon atom as given in the figure.

Step-2: Lewis Structure of CO2 for counting valence electrons around the terminal oxygen atoms

As a result, carbon is the first atom in the periodic table’s carbon family group. Oxygen is the first member of the oxygen family. It is the first element in the oxygen family on the periodic table. The electronegative value of the oxygen atom is higher than that of the carbon atom in the CO2 molecule. Furthermore, carbon has a four-electron limit since it is the less electronegative element in the CO2 molecule.

In the CO2 Lewis structure diagram, the carbon atom can be the center atom of the molecule. As a result, central carbon in the CO2 Lewis structure, with all two oxygen atoms arranged in a linear geometry.

Add valence electron around the oxygen atom, as given in the figure.

Step-3: Lewis dot Structure for CO2 generated from step-1 and step-2

Connect the exterior and core central atom of the CO2 molecule with two double C-O bonds. In this stage, use two oxygen atoms on the outside of the CO2 molecule to the central carbon atom in the middle.

Count how many electrons from the outermost valence shell have been used in the CO2 structure so far. Each C-O double bond carries two electrons because each carbon atom is connected to two oxygen atoms by two C-O double bonds. Bond pairings of C-O are what they’re called.

So, out of the total of 16 valence electrons available for the CO2 Lewis structure, we used eight electrons for the CO2 molecule’s two C-O double bonds. The CO2 molecule has no lone pairs of electrons in the central carbon atom.

Place the valence electrons in the C-O bond pairs starting with the core carbon, two oxygen atoms in the CO2 molecule. In the CO2 Lewis structure diagram, we always begin by introducing valence electrons from the central carbon atom(in step1). As a result, wrap around the central carbon atom’s bond pair valence electrons first (see figure for step1).

The carbon atom in the molecule gets only 8 electrons around its molecular structure. This central carbon atom is octet stable. But it has no lone pairs. The oxygen molecule(O2) is a colorless gas. It is the very essential element in our atmosphere. When fuel undergoes a combustion reaction with oxygen, it forms carbon dioxide(CO2).

Coal is the natural form of carbon. It is used as one of the classic fuels for industrial uses. There are different types of carbon. Graphite is another form of carbon. Graphite formed due to aggregation of carbon resonating molecular layer. In the higher end, diamond comes on the list. Its strength is very high.

Oxygen requires 8 electrons in its outermost valence shell to complete the molecular octet stability, 8 electrons bond pairs in two C-O double bonds, and no lone pairs in the central carbon atom. Two lone pairs of electrons on the oxygen atoms of the CO2 molecule are placed in a linear geometry. Oxygen already shares 8 electrons to the two C-O double bonds. Then place the valence electron in the oxygen atoms, it placed around six electrons on each atom(step-2). There are 8 valence electrons placed around two oxygen atoms as lone pair of electrons.

We’ve positioned 8 electrons around the two-terminal oxygen atoms(step-3), which is represented by a dot, in the CO2 molecular structure above. The oxygen atom completes its molecular octet stability in the CO2 molecule because it possesses 8 electrons in its (two C-O double bonds) bond pairs with two oxygen in the outermost valence shell.

Count how many outermost valence shell electrons have been used so far using the CO2 Lewis structure. Two electron bond pairs are shown as dots in the CO2 chemical structure, whereas two single bonds each contain four electrons. The outermost valence shell electrons of the CO2 molecule(bond pairs) are 8 as a result of the calculation. The total valence electron in an oxygen atom is 8.

So far, we’ve used 16 of the CO2 Lewis structure’s total 16 outermost valence shell electrons. no lone pairs of electrons on the carbon atom in the linear geometry of the CO2 molecule.

Complete the middle carbon atom stability and, if necessary, apply a covalent bond. The central carbon atom undergoes octet stability(due to two double bond pairs of electrons).

The core atom in the CO2 Lewis structure is carbon, which is bonded to the two oxygen atoms by double bonds (two C-O). With the help of two double bonds, it already shares 8 electrons. As a result, the oxygen follows the octet rule and has 8 electrons surrounding it on the two terminals of the CO2 molecule’s linear geometry.

How to calculate the formal charge on oxygen and carbon atoms in CO2 Lewis Structure?

Calculating formal charge on the carbon of CO2 molecule:

The formal charge on the CO2 molecule’s carbon central atom often corresponds to the actual charge on that carbon central atom. In the following computation, the formal charge will be calculated on the central carbon atom of the CO2 Lewis dot structure.

To calculate the formal charge on the central carbon atom of the CO2 molecule by using the following formula:
The formal charge on the carbon atom of CO2 molecule= (V. E(C)– L.E(C) – 1/2(B.E))
V.E (C) = Valence electron in a carbon atom of CO2 molecule
L.E(C) = Lone pairs of an electron in the carbon atom of the CO2 molecule.
B.E = Bond pair electron in C atom of CO2 molecule
calculation of formal charge on carbon atom in CO2 molecule

The carbon core atom (two double bonds connected to two oxygen atoms ) of the CO2 molecule has four valence electrons, no lone pairs of electrons(zero electrons), and 8 bonding pairing valence electrons. Put these values for the carbon atom in the formula above.

Formal charge on carbon atom of CO2 molecule = (4- 0-(8/2)) =0

In the Lewis structure of CO2, the formal charge on the central carbon atom is zero.

Calculating formal charge on the oxygen of CO2 molecule:

The formal charge on the CO2 molecule’s oxygen terminal atom often corresponds to the actual charge on that oxygen terminal atom. In the following computation, the formal charge will be calculated on the terminal oxygen atom of the CO2 Lewis dot structure.

To calculate the formal charge on the terminal oxygen atom of the CO2 molecule by using the following formula:
The formal charge on the oxygen atom of CO2 molecule= (V. E(S)– L.E(S) – 1/2(B.E))
V.E (S) = Valence electron in a oxygen atom of CO2 molecule
L.E(S) = Lone pairs of an electron in the oxygen atom of the CO2 molecule.
B.E = Bond pair electron in O atom of CO2 molecule
calculation of formal charge on oxygen atom in CO2 molecule

The oxygen terminal atom (one double bond connected to one carbon atom) of the CO2 molecule has six valence electrons, two lone pairs of electrons(four electrons), and 4 bonding pairing valence electrons. Put these values for the oxygen atom in the formula above.

Formal charge on oxygen atom of CO2 molecule = (6- 4-(4/2)) =0

In the Lewis structure of CO2, the formal charge on the terminal oxygen atom is zero.

Summary:

In this post, we discussed the method to construct the CO2 Lewis structure. First, the valence electrons are placed around the carbon atom. Second, place the valence electron on the oxygen atoms. Finally, when we combined the first and second steps. It gives CO2 Lewis structure. Need to remember that, if you follow the above-said method, you can construct molecular dot structure very easily.