I’m super excited to teach you the lewis structure of NOCl in just 6 simple steps.
Infact, I’ve also given the step-by-step images for drawing the lewis dot structure of NOCl molecule.
So, if you are ready to go with these 6 simple steps, then let’s dive right into it!
Lewis structure of NOCl contains a double bond between the Nitrogen (N) & Oxygen (O) atom and a single bond between the Nitrogen (N) and Chlorine (Cl) atom. The Nitrogen atom (N) is at the center and it is surrounded by Oxygen and Chlorine atoms. The Nitrogen has 1 lone pair, Oxygen has 2 lone pairs and the Chlorine has 3 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 NOCl).
6 Steps to Draw the Lewis Structure of NOCl
Step #1: Calculate the total number of valence electrons
Here, the given molecule is NOCl. In order to draw the lewis structure of NOCl, first of all you have to find the total number of valence electrons present in the NOCl 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 NOCl
- For Nitrogen:
Nitrogen is a group 15 element on the periodic table.
Hence, the valence electrons present in nitrogen is 5 (see below image).
- For Oxygen:
Oxygen is a group 16 element on the periodic table.
Hence, the valence electron present in oxygen is also 6 (see below image).
- For Chlorine:
Chlorine is a group 17 element on the periodic table.
Hence, the valence electron present in chlorine is 7 (see below image).
Hence in a NOCl molecule,
Valence electrons given by Nitrogen (N) atom = 5
Valence electrons given by Oxygen (O) atom = 6
Valence electrons given by Chlorine (Cl) atom = 7
So, total number of Valence electrons in NOCl molecule = 5 + 6 + 7 = 18
Step #2: Select the center atom
While selecting the 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).
Here in the NOCl molecule, if we compare the nitrogen atom (N), oxygen atom (O) and chlorine (Cl) atom, then the nitrogen is less electronegative than oxygen and chlorine.
So, nitrogen should be placed in the center and the oxygen and chlorine atoms will surround it.
Step #3: Put two electrons between the atoms to represent a chemical bond
Now in the above sketch of NOCl molecule, put the two electrons (i.e electron pair) between the nitrogen atom, chlorine atom and oxygen atom to represent a chemical bond between them.
These pairs of electrons present between the Nitrogen (N), Chlorine (Cl) and Oxygen (O) atoms form a chemical bond, which bonds these atoms with each other in a NOCl 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 NOCl, the outer atoms are oxygen atom and chlorine atom.
So now, you have to complete the octet on these atoms (because oxygen and chlorine both require 8 electrons to have a complete outer shell).
Now, you can see in the above image that oxygen and chlorine atoms form an octet.
Also, only 16 valence electrons of NOCl molecule are used in the above structure.
But there are total 18 valence electrons in NOCl molecule (as calculated in step #1).
So the number of electrons left to be kept on the central atom = 18 – 16 = 2.
So let’s keep these two electrons (i.e 1 electron pair) on the central atom.
Now, let’s move to the next step.
Step #5: Check whether the central atom has octet or not. If it does not have an octet, then move the electron pair from the outer atom to form a double bond or triple bond
In this step, we have to check whether the central atom (i.e nitrogen) has an octet or not.
In simple words, we have to check whether the central Nitrogen (N) atom has 8 electrons or not.
As you can see from the above image, the central atom (i.e nitrogen) has only 6 electrons. So it does not fulfill the octet rule.
Now, in order to fulfill the octet of nitrogen atom, we have to move the electron pair from the outer atom (i.e oxygen atom) to form a double bond.
Now you can see from the above image that the central atom (i.e nitrogen), is having 8 electrons.
So it fulfills the octet rule.
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 nitrogen atom (N), oxygen atom (O) as well as chlorine atom (Cl).
For that, you need to remember the formula of formal charge;
Formal charge = Valence electrons – Nonbonding electrons – (Bonding electrons)/2
- For Nitrogen:
Valence electrons = 5 (as it is in group 15)
Nonbonding electrons = 2
Bonding electrons = 6
- For Oxygen:
Valence electron = 6 (as it is in group 16)
Nonbonding electrons = 4
Bonding electrons = 4
- For Chlorine:
Valence electron = 7 (as it is in group 17)
Nonbonding electrons = 6
Bonding electrons = 2
|Formal charge||=||Valence electrons||–||Nonbonding electrons||–||(Bonding electrons)/2|
So you can see above that the formal charges on nitrogen, oxygen as well as chlorine are “zero”.
Hence, there will not be any change in the above structure and the above lewis structure of NOCl is the final stable structure only.
Each electron pair (:) in the lewis dot structure of NOCl represents the single bond ( | ). So the above lewis dot structure of NOCl can also be represented as shown below.