The Lewis structure of N3– contains two double bonds between the three nitrogen atoms. The left nitrogen atom and right nitrogen atom have two lone pairs, and the center nitrogen atom does not have any lone pair.
Plus, there is a negative (-1) charge on each nitrogen atom.
Steps
By using the following steps, you can easily draw the Lewis structure of N3–:
#1 Draw skeleton
#2 Show chemical bond
#3 Mark lone pairs
#4 Complete octet on central atom
#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… nitrogen is a group 15 element. Hence, nitrogen has five valence electrons.
Now N3– has three nitrogen atoms.
So the total number of valence electrons = valence electrons of nitrogen atom × 3
And N3– has a negative (-1) charge, so we have to add one more electron.
Therefore, the total number of valence electrons = 15 + 1 = 16
- Now decide the central atom
There are three nitrogen atoms in N3–. Hence, we can assume any one as the central atom. Let’s assume that center nitrogen is the central atom.
So now, put three nitrogens next to each other. And draw the rough skeleton structure for the Lewis structure of N3– something like this:
Also read: How to draw Lewis structure of Cl2 (4 steps)
#2 Show chemical bond
Place two electrons between the atoms to show a chemical bond. Since center nitrogen is surrounded by two other nitrogens, use four electrons to show two chemical bonds as follows:
#3 Mark lone pairs
As calculated earlier, we have a total of 16 valence electrons. And in the above structure, we have already used four valence electrons. Hence, twelve valence electrons are remaining.
Two valence electrons represent one lone pair. So twelve valence electrons = six lone pairs.
Note that nitrogen is a period 2 element, so it can not keep more than 8 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 left nitrogen and right nitrogen, so left nitrogen and right nitrogen will get three lone pairs. And the central atom (center nitrogen) will not get any lone pair, because all six lone pairs are used.
So the Lewis structure of N3– looks something like this:
In the above structure, you can see that the octet is completed on outside atoms. But, the central atom (center nitrogen) doesn’t form an octet.
So in the next step, we have to complete the octet on the central atom.
Also read: How to draw Lewis structure of COCl2 (5 steps)
#4 Complete octet on central atom
Remember that nitrogen is a period 2 element, so it can not keep more than 8 electrons in its last shell.
Now center nitrogen already has four valence electrons. Hence, center nitrogen needs four more valence electrons to complete its octet.
So convert one lone pair from the left nitrogen atom and right nitrogen atom to make a new bond with the center nitrogen atom. And then, the Lewis structure of N3– looks something like this:
In the above structure, you can see that the octet is completed on the central atom (center nitrogen), and also on the outside atom. 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 BH3 (3 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 left nitrogen and right nitrogen atom
Valence electrons = 5
Nonbonding electrons = 4
Bonding electrons = 4
Formal charge = 5 – 4 – ½ (4) = -1
- For center nitrogen atom
Valence electrons = 5
Nonbonding electrons = 0
Bonding electrons = 8
Formal charge = 5 – 0 – ½ (8) = +1
Mention the formal charges of atoms on the structure. So the Lewis structure of N3– 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 N3–.
And each horizontal line drawn in the above structure represents a pair of bonding valence electrons.
Now N3– is an ion having a negative (-1) charge, so draw brackets around the above Lewis structure and mention that charge on the top right corner. And then, the Lewis structure of N3– looks something like this:
Related
- Lewis structure of Cl2
- Lewis structure of COCl2
- Lewis structure of BH3
- Lewis structure of NCl3
- Lewis structure of BrF5
External links
- Drawing the Lewis Structure for N3 – The University of Maryland
- N3- Lewis Structure in 6 Steps (With Images) – Pediabay
- Chemical Bonding: N3- Lewis Structure – The Geoexchange
- N3- lewis structure, molecular geometry, hybridization, bond angle – Topblogtenz
- N3- (Azide) Ion Lewis Structure – Chemistry School
- Draw and explain the Lewis dot diagram for the N3- ion – Homework.Study.com
- N3- Lewis Structure (Azide Ion) – Pinterest
- What is the Lewis structure of the azide ion? – Chemistry Stack Exchange
- Lewis Electron-Dot Structure for N3 – Wired Chemist
- What is the most stable Lewis Structure for N3? – Quora
- How many resonance structures does N3- have? – Socratic
- N3 lewis structure, Hybridization, Molecular Structure, Bond Angle and Shape – Geometry of Molecules
- Draw a Lewis structure for the azide ion, N3- – Chegg
- The azide ion, N3- , is a symmetrical ion, all of whose contributing resonance structures have formal charges. Draw three important contributing structures for this ion – Pearson
- Lewis Dot of the Azide Ion N3- – Kent’s Chemistry
- Lewis dot structure for N3- – Brainly
- What is the formal charge on each nitrogen in azide ion N3 – Studocu
- Draw the Lewis structure for N3 – Bartleby
- Draw the Lewis dot structure for N3 Show the formal charge of the atom – Numerade
- What is the Lewis structure of N3-? – Quizlet
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.