CFCl3 (trichlorofluoromethane) has one carbon atom, one fluorine atom, and three chlorine atoms.
In CFCl3 Lewis structure, there are four single bonds around the carbon atom, with three chlorine atoms and one fluorine atom attached to it. And the fluorine atom and each chlorine atom has three lone pairs.
Steps
Here’s how you can easily draw the CFCl3 Lewis structure step by step:
#1 Draw a rough skeleton structure
#2 Mention lone pairs on the atoms
#3 If needed, mention formal charges on the atoms
Now, let’s take a closer look at each step mentioned above.
#1 Draw a rough skeleton structure
- First, determine the total number of valence electrons
In the periodic table, carbon lies in group 14, and both fluorine and chlorine lie in group 17.
Hence, carbon has four valence electrons, and both fluorine and chlorine have seven valence electrons.
Since CFCl3 has one carbon atom, one fluorine atom, and three chlorine atoms, so…
Valence electrons of one carbon atom = 4 × 1 = 4
Valence electrons of one fluorine atom = 7 × 1 = 7
Valence electrons of three chlorine atoms = 7 × 3 = 21
And the total valence electrons = 4 + 7 + 21 = 32
Learn how to find: Carbon valence electrons, Fluorine valence electrons, and Chlorine valence electrons
- Second, find the total electron pairs
We have a total of 32 valence electrons. And when we divide this value by two, we get the value of total electron pairs.
Total electron pairs = total valence electrons ÷ 2
So the total electron pairs = 32 ÷ 2 = 16
- Third, determine the central atom
We have to place the least electronegative atom at the center.
Since carbon is less electronegative than fluorine and chlorine, assume that the central atom is carbon.
Therefore, place carbon in the center and fluorine and chlorine on either side.
- And finally, draw the rough sketch
#2 Mention lone pairs on the atoms
Here, we have a total of 16 electron pairs. And four bonds are already marked. So we have to only mark the remaining twelve electron pairs as lone pairs on the sketch.
Also remember that both (carbon and fluorine) are the period 2 elements, so they can not keep more than 8 electrons in their last shell. And chlorine is a period 3 element, so it can keep more than 8 electrons in its last shell.
Always start to mark the lone pairs from outside atoms. Here, the outside atoms are fluorine and chlorines.
So for fluorine and each chlorine, there are three lone pairs, and for carbon, there is zero lone pair because all twelve electron pairs are over.
Mark the lone pairs on the sketch as follows:
#3 If needed, mention formal charges on the atoms
Use the following formula to calculate the formal charges on atoms:
Formal charge = valence electrons – nonbonding electrons – ½ bonding electrons
For carbon atom, formal charge = 4 – 0 – ½ (8) = 0
For fluorine and each chlorine atom, formal charge = 7 – 6 – ½ (2) = 0
Here, the atoms do not have charges, so no need to mark the charges.
In the above structure, you can see that the central atom (carbon) forms an octet. And the outside atoms (fluorine and chlorines) also form an octet. Hence, the octet rule is satisfied.
Therefore, this structure is the stable Lewis structure of CFCl3.
Next: NCl2– Lewis structure
External links
- https://lambdageeks.com/cfcl3-lewis-structure/
- https://www.numerade.com/ask/question/cfcl3-i-need-draw-lewis-dot-structures-and-give-the-shapes-molecule-geometry-62396/
- https://oneclass.com/homework-help/chemistry/7026532-cfcl3-lewis-structure.en.html
- https://www.chegg.com/homework-help/questions-and-answers/following-pairs-substances-draw-lewis-structures-indicate-pair-polar-explain–chcl3-cfcl3–q17250457
Deep
Learnool.com was founded by Deep Rana, who is a mechanical engineer by profession and a blogger by passion. He has a good conceptual knowledge on different educational topics and he provides the same on this website. He loves to learn something new everyday and believes that the best utilization of free time is developing a new skill.