So you have seen the above image by now, right?
Let me explain the above image in short.
N2O lewis structure has 1 triple bond between the two Nitrogen atoms (N) and 1 single bond between the Nitrogen atom (N) and Oxygen atom (O). There are 3 lone pairs on both the Oxygen atom (O) and 1 lone pair on the outer Nitrogen atom (N).
If you haven’t understood anything from the above image of N2O lewis structure, then just stick with me and you will get the detailed step by step explanation on drawing a lewis structure of N2O.
So let’s move to the steps of drawing the lewis structure of N2O.
Steps of drawing N2O lewis structure
Step 1: Find the total valence electrons in N2O molecule
In order to find the total valence electrons in N2O molecule, first of all you should know the valence electrons present in the nitrogen atom as well as oxygen atom.
(Valence electrons are the electrons that are present in the outermost orbit of any atom.)
Here, I’ll tell you how you can easily find the valence electrons of nitrogen as well as oxygen using a periodic table.
Total valence electrons in N2O molecule
→ Valence electrons given by nitrogen atom:
You can see the 5 valence electrons present in the nitrogen atom as shown in the above image.
→ Valence electrons given by oxygen atom:
You can see the 6 valence electrons present in the oxygen atom as shown in the above image.
Total valence electrons in N2O molecule = valence electrons given by 2 nitrogen atoms + valence electrons given by 1 oxygen atom = 5(2) + 6 = 16.
Step 2: Select the central atom
For selecting the center atom, you have to remember that the atom which is less electronegative remains at the center.
Now here the given molecule is N2O and it contains nitrogen atoms (N) and oxygen atom (O).
You can see the electronegativity values of nitrogen atom (N) and oxygen atom (O) in the above periodic table.
If we compare the electronegativity values of nitrogen (N) and oxygen (O) then the nitrogen atom is less electronegative.
So here, one of the nitrogen atoms (N) is the center atom and the other nitrogen atom (N) & oxygen atom (O) are the outside atoms.
Step 3: Connect each atoms by putting an electron pair between them
Now in the N2O molecule, you have to put the electron pairs between the two nitrogen (N) atoms and between the nitrogen (N) & oxygen (O) atom.
This indicates that these atoms are chemically bonded with each other in a N2O molecule.
Step 4: Make the outer atoms stable
Now in this step, you have to check the stability of the outer atoms.
Here in the sketch of N2O molecule, you can see that the outer atoms are nitrogen atom and oxygen atom.
These outer nitrogen and oxygen atoms are forming an octet and hence they are stable.
Also, in step 1 we have calculated the total number of valence electrons present in the N2O molecule.
The N2O molecule has a total 16 valence electrons and all these valence electrons are used in the above sketch of N2O.
Hence there are no remaining electron pairs to be kept on the central atom.
So now let’s proceed to the next step.
Step 5: Check the octet on the central atom. If it does not have octet, then shift the lone pair to form a double bond or triple bond.
In this step, you have to check whether the central nitrogen atom (N) is stable or not.
In order to check the stability of the central nitrogen (N) atom, we have to check whether it is forming an octet or not.
Unfortunately, the central nitrogen atom is not forming an octet here. Nitrogen has only 4 electrons and it is unstable.
Now to make this nitrogen atom stable, you have to shift the electron pair from the outer atom so that the central nitrogen atom can have 8 electrons (i.e octet).
But from which atoms should you shift the electron pair?
From oxygen? Or
So remember that you have to shift the electron pair from the atom which is less electronegative.
This is because the less electronegative atom has more tendency to donate the electron.
Here if we compare the nitrogen atom and oxygen atom, then the nitrogen atom is less electronegative.
So you have to shift the electron pair from the nitrogen atom.
But after shifting one electron pair, the central nitrogen atom is still not forming an octet as it has only 6 electrons.
So again we have to shift one more electron pair from the nitrogen atom.
After shifting this electron pair, the central nitrogen atom will get 2 more electrons and thus its total electrons will become 8.
You can see from the above picture that the central nitrogen atom is forming an octet.
And hence the central nitrogen atom is stable.
Now let’s proceed to the final step to check whether the lewis structure of N2O is stable or not.
Step 6: Check the stability of lewis structure
Now you have come to the final step in which you have to check the stability of lewis structure of N2O.
The stability of lewis structure can be checked by using a concept of formal charge.
In short, now you have to find the formal charge on nitrogen (N) atoms as well as oxygen (O) atom present in the N2O molecule.
For calculating the formal charge, you have to use the following formula;
Formal charge = Valence electrons – (Bonding electrons)/2 – Nonbonding electrons
For outer Nitrogen (N) atom:
Valence electrons = 5 (because nitrogen is in group 15)
Bonding electrons = 6
Nonbonding electrons = 2
For central Nitrogen (N) atom:
Valence electrons = 5 (because nitrogen is in group 15)
Bonding electrons = 8
Nonbonding electrons = 0
For Oxygen (O) atom:
Valence electrons = 6 (because oxygen is in group 16)
Bonding electrons = 2
Nonbonding electrons = 6
From the above calculations of formal charge, you can see that the central nitrogen (N) atom has +1 charge and the oxygen (O) atom has -1 charge.
So let’s keep these charges on the respective atoms of the N2O molecule.
The +1 and -1 charge from the above sketch gets canceled and the above lewis dot structure of N2O is the stable lewis structure.
In the above lewis dot structure of N2O, you can also represent each bonding electron pair (:) as a single bond (|). By doing so, you will get the following lewis structure of N2O.
I hope you have completely understood all the above steps.
For more practice and better understanding, you can try other lewis structures listed below.
Try (or at least See) these lewis structures for better understanding:
|PCl3 lewis structure
|BCl3 lewis structure
|CF4 lewis structure
|XeF2 lewis structure
|XeF4 lewis structure
|PO43- lewis structure
Jay is an educator and has helped more than 100,000 students in their studies by providing simple and easy explanations on different science-related topics. He is a founder of Pediabay and is passionate about helping students through his easily digestible explanations.
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