The Lewis structure of CH3NO2 contains five single bonds and one double bond, with carbon and nitrogen in the center. The carbon is attached with three hydrogens, and nitrogen is attached with two oxygens. The top oxygen has three lone pairs, right oxygen has two lone pairs, and nitrogen atom, 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 CH3NO2.
#1 Draw skeleton
#2 Show chemical bond
#3 Mark lone pairs
#4 Complete octet on atoms
#5 Calculate formal charge and check stability
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, nitrogen is a group 15 element, and oxygen is a group 16 element. Hence, carbon has four valence electrons, hydrogen has one valence electron, nitrogen has five valence electrons, and oxygen has six valence electrons.
Now CH3NO2 has one carbon atom, three hydrogen atoms, one nitrogen atom, and two oxygen atoms.
So the total number of valence electrons = valence electrons of carbon atom + (valence electrons of hydrogen atom × 3) + valence electrons of nitrogen atom + (valence electrons of oxygen atom × 2)
Therefore, the total number of valence electrons = 4 + 3 + 5 + 12 = 24
- 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, nitrogen, and oxygen.
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, nitrogen, and oxygen as follows:
Electronegativity value of carbon = 2.55
Electronegativity value of nitrogen = 3.04
Electronegativity value of oxygen = 3.44
Obviously, carbon is less electronegative than nitrogen and oxygen. Hence, assume that carbon is the central atom.
So now, put carbon in the center and nitrogen, two oxygens, and three hydrogens on either side. And draw the rough skeleton structure for the Lewis structure of CH3NO2 something like this:
Also read: How to draw Lewis structure of AsF3 (4 steps)
#2 Show chemical bond
Place two electrons between the atoms to show a chemical bond. Since carbon is surrounded by nitrogen, two oxygens, and three hydrogens, use twelve electrons to show six chemical bonds as follows:
#3 Mark lone pairs
As calculated earlier, we have a total of 24 valence electrons. And in the above structure, we have already used twelve valence electrons. Hence, twelve valence electrons are remaining.
Two valence electrons represent one lone pair. So twelve valence electrons = six lone pairs.
Note that all (carbon, nitrogen, and oxygen) 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, oxygens, and nitrogen. But hydrogen can not keep more than 2 electrons in its last shell. Hence, don’t mark the lone pairs on hydrogen.
So each oxygen will get three lone pairs. And nitrogen and the central atom (carbon) will not get any lone pair, because all six lone pairs are used.
Now draw the Lewis structure of CH3NO2 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 (except nitrogen).
So in the next step, we have to complete the octet on nitrogen.
Also read: How to draw Lewis structure of NO2Cl (5 steps)
#4 Complete octet on atoms
Remember that nitrogen is a period 2 element, so it can not keep more than 8 electrons in its last shell.
Now nitrogen already has six valence electrons. Hence, nitrogen needs two more valence electrons to complete its octet.
So convert one lone pair from the oxygen atom to make a new bond with the nitrogen atom. And then, the Lewis structure of CH3NO2 looks 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 BeCl2 (4 steps)
#5 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 nitrogen atom
Valence electrons = 5
Nonbonding electrons = 0
Bonding electrons = 8
Formal charge = 5 – 0 – ½ (8) = +1
- For top oxygen atom
Valence electrons = 6
Nonbonding electrons = 6
Bonding electrons = 2
Formal charge = 6 – 6 – ½ (2) = -1
- For right oxygen atom
Valence electrons = 6
Nonbonding electrons = 4
Bonding electrons = 4
Formal charge = 6 – 4 – ½ (4) = 0
Mention the formal charges of atoms on the structure. So the Lewis structure of CH3NO2 looks something like this:
In the above structure, you can see that the formal charges of atoms are closer to zero. Therefore, this is the most stable Lewis structure of CH3NO2.
And each horizontal line drawn in the above structure represents a pair of bonding valence electrons.
Related
- Lewis structure of AsF3
- Lewis structure of NO2Cl
- Lewis structure of BeCl2
- Lewis structure of CH2N2
- Lewis structure of KrF2
External links
- Chemical Bonding: CH3NO2 Lewis Structure – The Geoexchange
- CH3NO2 Lewis Structure in 6 Steps (With Images) – Pediabay
- CH3NO2 Lewis structure, molecular geometry, bond angles, resonance – Topblogtenz
- CH3NO2 Lewis Structure, Molecular Geometry, Hybridization, and Polarity – Techiescientist
- CH3NO2 Lewis Structure (Nitromethane) – Pinterest
- Draw and explain the Lewis diagram for nitromethane, CH3NO2 – Homework.Study.com
- Draw the best Lewis structure of CH3NO2, a neutral compound – Brainly
- Draw the Lewis structure (including all resonance structures) for nitromethane (CH3NO2) – Chegg
- Compare and contrast the Lewis structures of nitromethane, CH3NO2, and methyl nitrite, CH3ONO – Quizlet
- Draw the Lewis structure (including resonance structures) for nitromethane (CH3NO2) – Bartleby
- Hybridization of N in CH3NO2? – Chemical Forums
Deep
Rootmemory.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.