CO₂ (Carbon dioxide) Lewis Structure and Shape

Carbon dioxide (CO₂) lewis structure has two oxygen atoms and one carbon atom. There are two double bonds around carbon atom in the CO₂. No lone pairs on carbon atom and each oxygen atom has two lone pairs on their valence shells. Shape of CO₂ is linear. Steps of drawing the lewis structure of CO₂ are explained in detail in this tutorial.

CO₂ lewis structure and Shape

In the lewis structure of CO₂, you can see there are two double bonds around carbon atom. Each oxygen atom has two lone pairs and carbon atom does not have a lone pair. Also, there are no charges in oxygen atoms and carbon atom.

When we discuss about the shape, there are two sigma bonds around carbon atom and that carbon atom does not have lone pairs. Therefore, it should be linear shape around carbon atom.

Steps of drawing lewis structure of CO₂

There are several steps to draw the lewis structure of CO₂ and studying this carefully will guide you to draw lewis structures easily in your examinations.

1. Determine total number of electrons of the valance shells of carbon and oxygen atoms
2. Total electrons pairs existing as lone pairs and bonds
3. Determine center atom and drawing the sketch
4. Mark lone pairs on atoms
5. Mark charges on atoms if there are charges on atoms.
6. Check the stability and minimize charges on atoms by converting lone pairs to bonds to obtain best lewis structure.

Total number of electrons of the valance shells of CO₂

There are oxygen and carbon as elements in carbon dioxide. Oxygen belongs to the group VIA and contains six electrons in its last shell. Carbon belongs to the group IVA and has four electrons in its valence shell. Now we know how many electrons includes in valence shells of oxygen atom.

To find out total valence electrons given by a particular element, you should multiply number of electrons of the valance shell by the number of atoms of that element.

• valence electrons given by oxygen atoms = 6 * 2 = 12
• valence electrons given by carbon atom = 4 * 1 = 4

• Total valence electrons = 12 + 4 = 16

Total valence electrons pairs in ozone

Total valance electrons pairs = σ bonds + π bonds + lone pairs at valence shells

Total electron pairs are determined by dividing the number total valence electrons by two. For, CO₂, Total pairs of electrons are 8.

Sketch and selection of center atom of CO₂ molecule

We know carbon has the greatest chance to be the center atom of the carbon dioxide because carbon's valence (4) is higher than oxygen's valence (2). Now, we can draw the sketch of CO₂ as below.

Lone pairs on atoms

After determining the center atom and sketch of CO₂ molecule, we can start to mark lone pairs on atoms. Remember that, there are total of 8 electron pairs.

• There are already two C-O bonds in the above drawn sketch. Therefore, there are only six (8-2) electron pairs remains to mark on atoms.
• Usually, those remaining electron pairs should be started to mark on outside atoms. Also, remember that oxygen atom cannot keep more than eight electrons in its las shell. Considering these facts, we can mark electron pairs on oxygen atoms.
• In this step, each oxygen will keep three lone pairs. Now, all remaining six electrons pairs are marked.
• So, there are no more lone pairs to mark in carbon atom.

Mark charges on atoms and check octal rule

If there are charges on atoms in the above drawn CO₂ structure, they should be marked as the next step. Yes, there are charges on each oxygen atom and carbon atom as the below figure. Determining the charges is important to find the best lewis structure. That's why we are trying to find charges.

Check the stability and minimize charges on atoms by converting lone pairs to bonds

When there are charges on every atom in a molecule, that structure is not stable. Therefore, we have to reduce charges of atoms. We can convert a lone pair of oxygen atom to make a bond with carbon atom as the first step of reducing charges.

Now, you can see, charges o atoms are reduced. If can, we should furthermore reduce charges. Yes, we can convert a lone pair of other oxygen atom to make a bond with carbon atom. Then, there will be no charges on atoms. Also, there are two double bonds around carbon atoms in the lewis structure of CO₂.

Questions

I know carbon dioxide is an acidic compound. Can I prove that from lewis structure of carbon dioxide?

Hydroxyl ions can attack the carbon atom in CO₂ because carbon atoms is positively polarized due to oxygen atoms.

Can I say CO₂ is a non-polar compound by looking its lewis structure

When you drew the lewis structure of CO₂, its shape is linear. Because molecule is symmetric around carbon atom and two oxygen atoms are located in a same line, CO₂ become a non-polar compound. But, remenber that carbon atoms and oxygen atoms have polarized due to their different electronegativity values. Then, you will understand due to the linear shape and same atoms in a same line in CO₂ molecule, CO₂ become a non-polar compound.

lewis structure for CO₂ and CO

In CO, there is only one double bond between carbon and oxygen atom. But, in CO₂, there are two double bonds between carbon and oxygen atoms.

how many double bonds does CO₂ have in its lewis structure

There are two double bonds in CO₂ lewis structure. All these two double bonds are located around carbon atom. Therfore, hybridization of carbon is sp.