Lewis Structure of CH3SH (With 6 Simple Steps to Draw!)

Ready to learn how to draw the lewis structure of CH3SH?

Awesome!

Here, I have explained 6 simple steps to draw the lewis dot structure of CH3SH (along with images).

So, if you are ready to go with these 6 simple steps, then let’s dive right into it!

Lewis structure of CH3SH contains three C-H bonds, one S-H bond and one C-S bond. The Carbon atom (C) is at the center and it is surrounded by 3 Hydrogen atoms (H) and one S-H bond. The sulfur atom has 2 lone pairs.

Let’s draw and understand this lewis dot structure step by step.

(Note: Take a pen and paper with you and try to draw this lewis structure along with me. I am sure you will definitely learn how to draw lewis structure of CH3SH).

6 Steps to Draw the Lewis Structure of CH3SH

Step #1: Calculate the total number of valence electrons

Here, the given molecule is CH3SH. In order to draw the lewis structure of CH3SH, first of all you have to find the total number of valence electrons present in the CH3SH molecule.
(Valence electrons are the number of electrons present in the outermost shell of an atom).

So, let’s calculate this first.

Calculation of valence electrons in CH3SH

• For Carbon:

Carbon is a group 14 element on the periodic table. ^[1]

Hence, the valence electrons present in carbon is 4 (see below image).

• For Hydrogen: 

Hydrogen is a group 1 element on the periodic table. ^[2]

Hence, the valence electron present in hydrogen is 1 (see below image).

• For Sulfur:

Sulfur is a group 16 element on the periodic table. ^[3]

Hence, the valence electrons present in sulfur is 6 (see below image).

Hence in a CH3SH molecule, 

Valence electrons given by Carbon (C) atom = 4
Valence electron given by each Hydrogen (H) atom = 1
Valence electrons given by Sulfur (S) atom = 6
So, total number of Valence electrons in CH3SH molecule = 4 + 1(3) + 6 + 1 = 14

Step #2: Select the center atom (H is always outside)

While selecting the center atom, always put the least electronegative atom at the center.

(Remember: Fluorine is the most electronegative element on the periodic table and the electronegativity decreases as we move right to left in the periodic table as well as top to bottom in the periodic table). ^[4]

Here in the CH3SH molecule, if we compare the carbon atom (C), sulfur atom (S) and hydrogen atom (H), then hydrogen is less electronegative than sulfur and carbon. But as per the rule, we have to keep hydrogen outside.

So, carbon (which is less electronegative than sulfur) should be placed in the center and the remaining hydrogen atoms as well as S-H bond will surround it.

Step #3: Put two electrons between the atoms to represent a chemical bond

Now in the above sketch of CH3SH molecule, put the two electrons (i.e electron pair) between the carbon atom, sulfur atom and hydrogen atom to represent a chemical bond between them.

These pairs of electrons present between the Carbon (C), Sulfur (S) and Hydrogen (H) atoms form a chemical bond, which bonds these atoms with each other in a CH3SH molecule.

Step #4: Complete the octet (or duplet) on outside atoms. If the valence electrons are left, then put the valence electrons pair on the central atom

Don’t worry, I’ll explain!

In the Lewis structure of CH3SH, the outer atoms are hydrogen atoms as well as sulfur atom.

Hydrogen already has a duplet (see below image).

So now, you have to complete the octet on sulfur atom (because sulfur requires 8 electrons to have a complete outer shell).

Now, you can see in the above image that the sulfur atom forms an octet.

Also, all the 14 valence electrons of CH3SH molecule (as calculated in step #1) are used in the above structure. So there are no remaining electron pairs.

Hence there is no change in the above sketch of CH3SH.

Let’s move to the next step.

Step #5: Check whether the central atom has octet or not

In this step, we have to check whether the central atom (i.e carbon) has an octet or not. 

In simple words, we have to check whether the central Carbon (C) atom is having 8 electrons or not.

As you can see from the above image, the central atom (i.e carbon), is having 8 electrons. So it fulfills the octet rule and the carbon atom is stable.

Step #6: Final step – Check the stability of lewis structure by calculating the formal charge on each atom

Now, you have come to the final step and here you have to check the formal charge on carbon atom (C), sulfur atom (S) as well as each hydrogen atom (H).

For that, you need to remember the formula of formal charge;

Formal charge = Valence electrons – Nonbonding electrons – (Bonding electrons)/2

• For Carbon:
  Valence electrons = 4 (as it is in group 14)
  Nonbonding electrons = 0
  Bonding electrons = 8
• For Sulfur:
  Valence electron = 6 (as it is in group 16)
  Nonbonding electrons = 4
  Bonding electrons = 4
• For Hydrogen:
  Valence electron = 1 (as it is in group 1)
  Nonbonding electrons = 0
  Bonding electrons = 2

Formal charge	=	Valence electrons	–	Nonbonding electrons	–	(Bonding electrons)/2
C	=	4	–	0	–	8/2	=	0
S	=	6	–	4	–	4/2	=	0
H	=	1	–	0	–	2/2	=	0

So you can see above that the formal charges on carbon, sulfur as well as hydrogen are “zero”.

Hence, there will not be any change in the above structure and the above lewis structure of CH3SH is the final stable structure only.

Each electron pair (:) in the lewis dot structure of CH3SH represents the single bond ( | ). So the above lewis dot structure of CH3SH can also be represented as shown below.

Related lewis structures for your practice:
Lewis Structure of KrF4
Lewis Structure of TeCl4
Lewis Structure of AsO4 3-
Lewis Structure of XeF6
Lewis Structure of N2O3 

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