Hydrazine is an inorganic compound and a pnictogen hydride with the chemical formula N2H4. It’s also called Diazane, Diamine, or Nitrogen Hydride, and it’s an alkaline substance. It is extremely poisonous and is primarily employed as a foaming ingredient in the manufacture of polymer foams.
It’s also employed in the pharmaceutical and agricultural chemical sectors.
The lewis structure of N2H4, as well as its geometry, hybridization, and lewis structure, will be discussed in this article.
N2H4 Lewis Structure
The Lewis dot diagram, also known as the electron dot structure, is a visual depiction of a compound’s molecular formula as well as its electrons, which are depicted as dots.
Gilbert Newton Lewis, an American scientist, was the first to introduce these structures in 1916.
Lewis structures show the chemical bonding between atoms in a molecule as well as the number of lone pairs of electrons in the molecule.
These are representations of the molecule’s electronic structure and atomic bonding, with each dot representing an electron and two dots between the atoms representing a link.
N2H4’s Lewis structure is shown below.
Only the valence electrons of an atom participate in chemical bonding to meet the octet for that atom, as we already know. In the case of N2H4, nitrogen has five valence electrons while hydrogen only has one.
It’s worth noting that the octet rule does not apply to hydrogen, which can only be stable with two electrons.
As a result, each nitrogen atom forms a single connection with two hydrogen atoms and the other nitrogen atom, fulfilling the octet rule for all of the atoms involved.
N2H4 Lewis Structure Diagram
The Lewis diagram for hydrazine should be drawn in the following manner:
• First and foremost, we must determine the total number of valence electrons in the molecule.
Nitrogen is a group 15 element, which means it has five electrons in its outermost shell, whereas hydrogen is the first element in the periodic table and has only one valence electron.
The total number of valence electrons present in one molecule N2H4 is calculated by adding the valence electrons of all the atoms.
Nitrogen has 5 Valence electrons, hence 2 * 5 = 10 for 2 Nitrogen atoms.
1 valence electron = 1 hydrogen atom; 4 * 1 = 4 hydrogen atoms = 1 hydrogen atom = 1 hydrogen atom = 1 hydrogen atom = 1 hydrogen atom = 1 hydrogen atom = 1 hydrogen atom =
As a result, N2H4 has a total of 14 valence electrons.
• After that, we’ll try to create a rudimentary Lewis diagram by arranging the atoms in a specified arrangement connected by a single bond.
This is intended to provide us an estimate of the number of electrons that remain unbounded, as well as the amount of electrons that any atom will require to complete its octet.
• You might wonder why nitrogen and hydrogen molecules in the N2H4 molecule are arranged in this particular order, i.e. why are nitrogen atoms at the centre despite the fact that nitrogen is more electronegative than hydrogen.
Actually, the nitrogen atom requires three electrons to complete its octet, but the hydrogen atom only requires one. Placing nitrogen atoms in the centre of the molecule creates symmetry and facilitates electron sharing across different atoms.
• The octet of both nitrogen atoms is satisfied after sharing one electron each with two hydrogen atoms and the other nitrogen atom, as they each have a lone pair of electrons.
• As a result, the N2H4 molecule’s ultimate structure is as follows:
• Calculating the formal charge on any molecule can be used to determine the accuracy of its Lewis structure.
The formal charge is a theoretical concept used to determine the stability of the derived Lewis structure.
• Any given molecule’s formal charge should be close to zero for best stability. It is calculated separately for each atom in a molecule.
The following is the formula for calculating formal charge:
[Total number of valence e– in Free State] = Formal Charge (FC). – [Total number of non-bonding e– – 1/2 (Total number of bonding e–)] – [Total number of non-bonding e– – 1/2 (Total number of bonding e–)]
• To find the formal charge of the N2H4 molecule, do the following:
The total number of valence electrons in the free state for the nitrogen atom is 5.
The total number of nonbonding electrons is equal to two.
Total number of electrons in a bond Equals 6.
As a result, the formal charge on the nitrogen atom is 5 – 2 – 12. (6)
Total amount of valence electrons in free state for a hydrogen atom = 1.
The total amount of non-bonding electrons is equal to zero.
The total number of bonding electrons is equal to two.
As a result, the formal charge on the nitrogen atom is 1 – 0 – 12. (2)
• As a result, the N2H4 molecule’s total formal charge becomes zero, suggesting that the determined structure is stable and accurate.
When N, N Dimethylhydrazine has N2H2, but not N2H4 (hydrazine), why does it have hydrazine? Why isn’t it referred to as ‘Dimethyldiimide’? – According to Quora
The Valence Shell Electron Pair Repulsion (VSEPR) Theory postulates are used to calculate the molecular geometry of each molecule.
According to this idea, the electrons of various atoms inside a molecule seek to arrange themselves as far away as possible so that inter-electronic repulsion is minimised.
Inter-electronic repulsion exists between all electrons in a molecule, including lone pairs. However, because they are free in space, the maximal repulsion force exists between lone pair-lone pair.
As a result, the quantity of lone pairs and bonding pairs of electrons, as well as the distance and bond angle between these electrons, dictate the geometry of a molecule.
The distortion of bond angle in a molecule is also determined by inter-electronic repulsion.
To learn about the molecular geometry of N2H4, we’ll start with a centre atom.
All of the other atoms in a molecule are bound to the centre atom, according to the VSEPR hypothesis. Because both Nitrogen atoms are in the Lewis structure’s centre, any one of them can be regarded the central atom.
As a result, one nitrogen atom is bound to two hydrogen atoms and one nitrogen atom in N2H4.
According to the VSEPR theory, the nitrogen atom must develop a trigonal pyramidal structure if the three bound electrons and one lone pair of electrons are arranged as far apart as possible.
AXN notation is used to represent the molecular geometry of N2H4, where A is the central atom, X is the number of atoms linked to the central atom, and N is the number of lone pairs.
As a result, this notation for the N2H4 molecule can be represented as AX3N, indicating that it possesses trigonal pyramidal shape. The N2H4 molecule has a tetrahedral electron shape.
The geometry, bond angle, and hybridization for many compounds are represented in the table below using AXN notation:
As indicated in the table above, the bond angle is 109.5°. The following is the molecular geometry for the N2H4 molecule:
Hybridization is the process of combining one or more atomic orbitals of similar energy to create a completely new orbital with a different energy and shape than its constituent atomic orbitals.
Linus Pauling was the first to propose this concept in 1931.
The hybrid orbitals that result from the intermixing of atomic orbitals are given names based on their basic orbitals, i.e. the orbitals that were involved in their development.
One s and three p-orbitals, for example, were involved in the development of the sp3 hybrid orbital.
A simple formula can be used to determine the hybridization of any molecule, as shown below:
Number of sigma () bonds on central atom + lone pair on centre atom = hybridization
Now, using this formula, calculate the hybridization for the N2H4 molecule:
The number of sigma bonds is 3 in this case.
Also, the number of lone pairs equals one.
Hybridization = 3 + 1 as a result.
As a result, the N2H4 molecule’s hybridization is sp3.
In addition, as shown in the table above, a molecule with a trigonal pyramidal structure always possesses sp3 hybridization, with the one s and three p-orbitals at a 109.5° angle.
Polarity refers to a molecule’s presence of two opposed charges or poles.
The electronegativity mismatch between a molecule’s constituent atoms is responsible for the creation of these charges.
We know that the two nitrogen atoms in the N2H4 molecule are in the same plane and that there is no electronegativity difference between them, hence the link between them is non-polar.
The electronegativity mismatch between the nitrogen and hydrogen atoms causes the N2H4 molecule to be polar.
It’s worth noting that the two nitrogen atoms in the N2H4 molecule contain the same number of hydrogen atoms and lone pairs of electrons.
The hydrogen atoms connected to one Nitrogen atom, on the other hand, are in the vertical plane, while those attached to the other Nitrogen atom are in the horizontal plane.
The N2H4 molecule develops a net dipole moment as a result of this.
Furthermore, the N2H4 molecule’s structure is twisted, causing the dipole moments of distinct atoms to not cancel out.
The N2H4 molecule has a net dipole moment of 1.85 D, suggesting that it is polar.
N2H4 has the following properties.
The following table lists the key features of the N2H4 molecule:
|Appearance||Fuming, oily liquid|
|Molecular weight||32.0452 g/mol|
|Boiling Point||114 °C|
|Melting Point||2 °C|
|Dipole Moment||1.85 D|
|Solubility||Miscible in water|
Here are a few of hydrazine’s most important applications:
• It’s utilised in the manufacturing of polymer foams.
• Because it can be held for a long time, it is employed as a storable propellant for space rockets.
• It’s a precursor to a lot of insecticides.
• Pharmaceutical and agrochemical industries use it.
• It’s used to electrolytically plate metals onto glass and plastics.
• It is utilised as a corrosion inhibitor in cooling water reactors.
• As an inorganic solvent, it’s employed.
The Lewis structure of the molecule N2H4 is as follows:
| Study.com | What is the Lewis structure of N2H4?
This Lewis structure has a formal charge of zero, indicating that it is the genuine article.
The N2H4 molecule has a trigonal pyramidal molecular geometry and a tetrahedral electron geometry.
N2H4 has an sp3 hybridization.
The N2H4 molecule has a dipole moment of 1.85 D.
I hope you now have a good understanding of N2H4’s Lewis structure, geometry, hybridization, and polarity. If you have any further questions, please ask them in the comments section.
Good luck with your studies! and take a look at some of my other posts.