Lewis structure of CH3F

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The Lewis structure of CH₃F contains four single bonds, with carbon in the center, and three hydrogens and fluorine on either side. There are three lone pairs on the fluorine atom, and carbon atom and hydrogen atom do not have any lone pair.

Steps

By using the following steps, you can easily draw the Lewis structure of CH₃F:

#1 Draw skeleton
#2 Show chemical bond
#3 Mark lone pairs
#4 Calculate formal charge and check stability (if octet is already completed on central atom)

Let’s one by one discuss each step in detail.

#1 Draw skeleton

In this step, first calculate the total number of valence electrons. And then, decide the central atom.

• Let’s calculate the total number of valence electrons

We know that… carbon is a group 14 element, hydrogen is a group 1 element, and fluorine is a group 17 element. Hence, carbon has four valence electrons, hydrogen has one valence electron, and fluorine has seven valence electrons.

Now CH₃F has one carbon atom, three hydrogen atoms, and one fluorine atom.

So the total number of valence electrons = valence electrons of carbon atom + (valence electrons of hydrogen atom × 3) + valence electrons of fluorine atom

Therefore, the total number of valence electrons = 4 + 3 + 7 = 14

• Now decide the central atom

We can not assume hydrogen as the central atom, because the central atom is bonded with at least two other atoms. And hydrogen has only one electron in its last shell, so it can not make more than one bond.

Therefore, choose the central atom from carbon and fluorine.

The atom with the least electronegative value is placed at the center. By looking at the periodic table, we get the electronegativity values for carbon and fluorine as follows:

Electronegativity value of carbon = 2.55
Electronegativity value of fluorine = 3.98

Obviously, carbon is less electronegative than fluorine. Hence, assume that carbon is the central atom.

So now, put carbon in the center and hydrogens and fluorine on either side. And draw the rough skeleton structure for the Lewis structure of CH₃F something like this:

Also read: How to draw Lewis structure of BrO₃^– (5 steps)

#2 Show chemical bond

Place two electrons between the atoms to show a chemical bond. Since carbon is surrounded by three hydrogens and fluorine, use eight electrons to show four chemical bonds as follows:

Also read: How to draw Lewis structure of NH₄⁺ (3 steps)

#3 Mark lone pairs

As calculated earlier, we have a total of 14 valence electrons. And in the above structure, we have already used eight valence electrons. Hence, six valence electrons are remaining.

Two valence electrons represent one lone pair. So six valence electrons = three lone pairs.

Note that both (carbon and fluorine) are the period 2 elements, so they can not keep more than 8 electrons in their last shell. And hydrogen is a period 1 element, so it can not keep more than 2 electrons in its last shell.

Also, make sure that you start marking these lone pairs on outside atoms first. And then, on the central atom.

The outside atoms are hydrogens and fluorine. But hydrogen can not keep more than 2 electrons in its last shell. Hence, don’t mark the lone pairs on hydrogen.

So fluorine will get three lone pairs. And the central atom (carbon) will not get any lone pair, because all three lone pairs are used.

Now draw the Lewis structure of CH₃F something like this:

In the above structure, you can see that the octet is completed on the central atom (carbon), and also on the outside atoms. Therefore, the octet rule is satisfied.

After completing the octet, one last thing we need to do is, calculate the formal charge and check the stability of the above structure.

Also read: How to draw Lewis structure of HNO (5 steps)

#4 Calculate formal charge and check stability

The following formula is used to calculate the formal charges on atoms:

Formal charge = valence electrons – nonbonding electrons – ½ bonding electrons

Collect the data from the above structure and then, write it down below as follows:

• For carbon atom

Valence electrons = 4
Nonbonding electrons = 0
Bonding electrons = 8

Formal charge = 4 – 0 – ½ (8) = 0

• For each hydrogen atom

Valence electrons = 1
Nonbonding electrons = 0
Bonding electrons = 2

Formal charge = 1 – 0 – ½ (2) = 0

• For fluorine atom

Valence electrons = 7
Nonbonding electrons = 6
Bonding electrons = 2

Formal charge = 7 – 6 – ½ (2) = 0

Mention the formal charges of atoms on the structure. So the Lewis structure of CH₃F looks something like this:

In the above structure, you can see that the formal charges of all atoms are zero. Therefore, this is the stable Lewis structure of CH₃F.

And each horizontal line drawn in the above structure represents a pair of bonding valence electrons.

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Related

• Lewis structure of BrO₃^–
• Lewis structure of NH₄⁺
• Lewis structure of HNO
• Lewis structure of BeH₂
• Lewis structure of AlCl₃

External video

• CH3F Lewis Structure: How to Draw the Lewis Structure for CH3F (Fluoromethane) – YouTube • Wayne Breslyn

External links

• Chemical Bonding: CH3F Lewis Structure – The Geoexchange
• CH3F lewis structure, molecular geometry, bond angle, polarity, electrons – Topblogtenz
• How is the Lewis structure for CH3F determined? – Quora
• CH3F Lewis Structure in 6 Steps (With Images) – Pediabay
• CH3F Lewis Structure, Molecular Geometry, Hybridization, and Polarity – Techiescientist
• CH3F Lewis Structure, Geometry – Kemicalinfo
• Draw the Lewis structure of methyl fluoride – Homework.Study.com
• How to draw CH3F Lewis Structure? – Science Education and Tutorials
• Draw the Lewis structure for CH3F – Chegg
• Draw a Lewis structure for each covalent molecule. a. CH3F b. N2H4 – Brainly