CF2S Lewis structure

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CF2S Lewis Structure
CF2S Lewis structure | Image: Learnool

CF2S has one carbon atom, two fluorine atoms, and one sulfur atom.

In CF2S Lewis structure, there are two single bonds and one double bond around the sulfur atom, with two fluorine atoms and one sulfur atom attached to it. Each fluorine atom has three lone pairs, and the sulfur atom has two lone pairs.

Steps

Use these steps to correctly draw the CF2S Lewis structure:

#1 First draw a rough sketch
#2 Mark lone pairs on the atoms
#3 Calculate and mark formal charges on the atoms, if required
#4 Convert lone pairs of the atoms, and minimize formal charges
#5 Repeat step 4 if needed, until all charges are minimized, to get a stable Lewis structure

Let’s discuss each step in more detail.

#1 First draw a rough sketch

  • First, determine the total number of valence electrons
Periodic table | Image: Learnool

In the periodic table, carbon lies in group 14, fluorine lies in group 17, and sulfur lies in group 16.

Hence, carbon has four valence electrons, fluorine has seven valence electrons, and sulfur has six valence electrons.

Since CF2S has one carbon atom, two fluorine atoms, and one sulfur atom, so…

Valence electrons of one carbon atom = 4 × 1 = 4
Valence electrons of two fluorine atoms = 7 × 2 = 14
Valence electrons of one sulfur atom = 6 × 1 = 6

And the total valence electrons = 4 + 14 + 6 = 24

  • Second, find the total electron pairs

We have a total of 24 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 = 24 ÷ 2 = 12

  • Third, determine the central atom

We have to place the least electronegative atom at the center.

Since carbon is less electronegative than fluorine and sulfur, assume that the central atom is carbon.

Therefore, place carbon in the center and fluorines and sulfur on either side.

  • And finally, draw the rough sketch
CF2S Lewis Structure (Step 1)
Rough sketch of CF2S Lewis structure | Image: Learnool

#2 Mark lone pairs on the atoms

Here, we have a total of 12 electron pairs. And three bonds are already marked. So we have to only mark the remaining nine 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 sulfur 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 fluorines and sulfur.

So for each fluorine and sulfur, there are three lone pairs, and for carbon, there is zero lone pair because all nine electron pairs are over.

Mark the lone pairs on the sketch as follows:

CF2S Lewis Structure (Step 2)
Lone pairs marked on CF2S Lewis structure | Image: Learnool

#3 Calculate and mark formal charges on the atoms, if required

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 (6) = +1

For each fluorine atom, formal charge = 7 – 6 – ½ (2) = 0

For sulfur atom, formal charge = 6 – 6 – ½ (2) = -1

Here, both carbon and sulfur atoms have charges, so mark them on the sketch as follows:

CF2S Lewis Structure (Step 3)
Formal charges marked on CF2S Lewis structure | Image: Learnool

The above structure is not a stable Lewis structure because both carbon and sulfur atoms have charges. Therefore, reduce the charges (as below) by converting lone pairs to bonds.

#4 Convert lone pairs of the atoms, and minimize formal charges

Convert a lone pair of the sulfur atom to make a new C — S bond with the carbon atom as follows:

CF2S Lewis Structure (Step 4)
Lone pair of sulfur is converted, and got the stable Lewis structure of CF2S | Image: Learnool

In the above structure, you can see that the central atom (carbon) forms an octet. And the outside atoms (fluorines and sulfur) also form an octet. Hence, the octet rule is satisfied.

Also, the above structure is more stable than the previous structures. Therefore, this structure is the stable Lewis structure of CF2S.

Next: PI5 Lewis structure

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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.

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