Carbon Tetrachloride (CCl4) Lewis Structure and Steps of Drawing
Carbon tetrachloride (CCl4) is an alkyl halide compound. There are four chlorine atoms and one carbon atom in CCl4 molecule. Lewis structure of CCl4 contains four C-Cl bonds. Carbon atom is the center atom and each chlorine atom has 3 lone pairs. We will learn how to draw the lewis structure of CCl4 step by step in this tutorial.
CCl4 lewis structure
According to the lewis structure of CCl4, you can see how chlorine atoms are connected with center carbon atom. There are only single bonds between chlorine atoms and carbon atom. As well, there are no charges on atoms and CCl4 does not have an overall charge. Each chlorine atom has three lone pairs in their valence shells.
Carbon tetrachloride (CCl4)
Carbon tetrachloride is a clear colorless liquid at room temperature and a noncombustible compound.
Steps of drawing lewis structure of CCl4
There are several steps to complete the lewis structure of CCl4. Each step of drawing is explained in detail in this tutorial.
- Find total number of electrons of the valance shells of carbon atom and chlorine atoms
- Determine total electrons pairs as lone pairs and bonds
- Find center atom and draw basic skeletal structure
- Mark lone pairs on atoms
- Mark charges on atoms if there are charges.
- 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 CCl4
There are only two elements in CCl4 molecule; carbon and chlorine. Chlorine is a group VIIA element in the periodic table and contains 7 electrons in its last shell. Carbon atom has 4 electrons in its last shell because it is a IV group element. Now we know how many electrons are included in valence shells of each atom.
- valence electrons given by carbon atom = 4 * 1 = 4
- valence electrons given by chlorine atoms = 7 * 4 = 28
- Total valence electrons = 4 + 28 = 32
Total valence electrons pairs
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, CCl4, total pairs of electrons are 16 (32/2) in their valence shells.
Center atom selection and draw basic skeletal of CCl4
To be the center atom, ability of having greater valance and being most electropositive element in the molecule are important facts.
Because, CCl4 is a simple molecule, it is not very difficult to select the center atom.
- Considering greater valence - Chlorine's highest valence is 7 and carbon's highest valence is 4. From that case, we can suggest that chlorine has the potential to be the center atom.
- Most electropositive element - Carbon's electronegativity is 2.5 and chlorine's electronegativity is 3.0 according to the Pauling's electronegativity scale. Therefore, carbon is more electropositive than chlorine. In that case, we can suggest that carbon has the potential to be the center atom.
- Now, there is a confusion between how to select the center atom.
- Now, we are going to consider the minimum valence of chlorine and carbon atoms to form stable compounds.
- Chlorine's minimum valence is 1 and carbons minimum (only) valence is 4. That means, there should be minimum number of four bonds around carbon atoms, if carbon form a stable compound.
- From above finding, we understand that carbon atom should be the center atom and basic skeletal structure can be drawn as below.
Mark lone pairs on atoms
After deciding the center atom and drawing of skeletal structure of CCl4 molecule, we can start to mark lone pairs on atoms. Remember that, there are total of 16 electron pairs to mark on atoms as bonds and lone pairs.
- There are already 4 bonds in the above drawn skeletal structure. Now only 12 (16-4) electron pairs are remaining to mark on atoms.
- Usually, those remaining electron pairs should be started to mark on outside atoms.
- Therefore, mark those electrons pairs on each chlorine atom; One chlorine atom will 3 lone pairs. So all remaining 12 lone pairs are marked on chlorine atoms.
Mark charges on atoms if there are and check the stability and minimize charges on atoms by converting lone pairs to bonds
There are no charges on atoms and we do not need to the step of reducing charges of atoms.
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