This article Illustrates all information about the Lewis Dot Structure. Lewis dot structure is useful in drawing the molecules and for finding the Hybridization, shapes, formal charges, and pairing of electrons.
SP3 Lewis structure is called Lewis dot structure or electron dot structure of electrons in molecules. Lewis structure represents the total number of lone pairs or Valence Shell electrons present in each atom of the molecule. This concept follows the “octet rule.”
How to Draw the Lewis structure for SP3?
Following are the steps for drawing lewis’s structure:
- Firstly, Select the Central Atom of molecules (Criteria of Central Atom are the least electronegative atom and having the largest size or highest atomic number) and try to maintain maximum covalency. Hydrogen and halogen can never be central atoms and other atoms spaced evenly around them.
- Calculate the valence shell electrons of the molecules by adding all valence electrons of each atom present in the molecule.Total electron= Valence electron of all atoms+ (-ve Charge)- (+ve Charge)
- Calculate the bond pairs electrons= 2* No. of bonds.
- Calculate the lone pairs of electrons = Total electrons- Bond pairs electrons. Lone pairs are used to satisfy the octet rule by assigning them to each atom or as double or triple bonds.
- Draw the skeleton of molecules using a single bond between the central atom and other atoms around it, followed by the octet rule.
- Finally, check the total electrons and complete the octet of all atoms around the central atom of molecules. Only the valance electrons are considered for drawing the Lewis structure, and the remaining valence electrons are used to complete the central atom octet by forming Covalent bonds.
SP3 Lewis Structure shape: What will be the Lewis Dot structure of CO2?
Lewis dot structure is the simplest representation of electrons around the individual atoms.
Following are the steps to draw the Lewis Structure:
- Total Valence electron of CO2 molecule = 16
- Central atom is C (Least Electronegative) =4 valence electrons
- Surrounding atoms is O= 6 valence electrons (2*6=12)
- Bond pairs electrons= 4( Single Bond line)
- Lone pairs electrons= 6 (used in form of Lone pair or Double and Triple bonds)
- Dot Structure of CO2 :
SP3 Lewis Structure shape:
Lewis dot structure does not show the shape of the molecules. This is only the representation of electrons around the atoms.
They only show the connectivity of the atoms. By the connection of atoms, we can predict the shape of the molecules. This will show the geometry of molecules.
SP3 Lewis Structure Formal Charge: How to calculate a formal charge?
The formal charge is the difference between electrons and an atom consisting of that electron to owes that in particularly SP3 lewis Structure.
The formal charge is the resonance of electrons around the atoms and calculated mathematically by using the formula, Formal charge= Valence electron – bond pairs electrons – lone pairs electrons.
Example: Nitrate ion (NO3–)
To calculate the formal charge on each atom use mathematical equation,
Nitrogen= 5(valence electron)- 4(bond pair electrons)-0(Lone pair electrons) =+1
Oxygen = 6-2-4 =0,
Oxygen = 6-1-6 =-1
Oxygen = 6-1-6 =-1
Another Example: CO2
Carbon = 4-0-4=0
So, the CO2 molecule has Zero formal charge.
We must write a formal charge for each atom except that has 0 Formal charges. So,(NO3–) the molecule should be a draw as the -ve formal charge should be present on the molecule which attracts electrons strongly, and the positive charge on the atom which attracts fewer electrons towards itself.
SP3 Lewis Structure lone pair: How to find Lone pairs of electrons?
Lone pairs of electrons are those electrons that do not undergo any covalent bonding, so these electrons are called unshared pairs of electrons or nonbonding electrons.
An SP3 Hybrid orbital consists of lone pairs of electrons, this can be explained with an example of CO2. We can only Count the no. of bond pairs or lone pairs around the central atom.
Calculate valance electrons =16 electrons
Lone pairs electrons= 6 (due to oxygen atoms) out of 6 (4 are unbonded pairs of electrons).
SP3 Hybridization: Explain the process of Hybridization?
Hybridization is the process of overlapping two different energy orbitals to form new orbitals. Overlapping orbitals interact with each other by head-to-head or tail-to-tail and by sideways overlapping.
For SP3 hybridization, there should be a presence of one S orbital and three P orbitals and by mixing this orbital formation, a new SP3 hybrid orbital takes place.
Example of SP3 Hybridization: CH4
Carbon: 1s2, 2s2, 2p2
SP3 Lewis Structure Resonance: What is resonance?
Resonance is defined as the delocalization of electrons from one atom to another atom without disturbing its position and the formation of a stable resonating structure in which equal distribution of charges takes place.
This could be explained with an example of NO3- (= 24 valence electrons). First, we draw the Lewis structure of NO3- and then calculate its formal Charge. Place the Nitrogen in the center and connect it with a single bond with Oxygen. After this distribute the valence electrons to the surrounding atoms of nitrogen by following the “octet rule”, and the remaining electrons to the central atom.
Resonance in NO3– :
Resonance structure is differed only in the electron’s pairs and not in the placement of atoms. The place of an atom is fixed and only the movement of electrons takes place in the resonance. So, these three structures below in the image are equivalent to each other.
SP3 Lewis Structure Octet Rule: What is the octet rule and how does it work?
When electrons gain, lose or are shared, a stable compound is formed, and there should be 8 electrons in their outermost shell.
The octet rule refers to filling the outermost electron with eight electrons at their highest energy level during Lewis’s structure drawing.
SP3 Polar and Non-Polar: What are polar and non-polar molecules?
Polar Molecules are those which have a huge electronegativity difference between the atoms. Two atoms do not share electrons equally during covalent bond formation. For Example, H2O in this oxygen is more electronegative than Hydrogen, and sharing of electrons is not equal. Some other examples are SO2, H2S, NH3, etc.
Nonpolar Molecules are those in which electrons are evenly distributed and have similar electronegativity or the difference between the electronegativity is very less. For example, CO2, CCl4, Homonuclear Diatomic elements, etc.
How can we tell a Lewis Structure is polar or non-polar?
The answer to this question is the Lewis Dot structure and visualize the Dipole moment of that molecules. The dipole moment is a vector quantity. If we take an example of HF, in this Florine most electronegative elements so that end of the molecule becomes slightly negative and other ends of the molecules become slightly positive, there is the generation of two-pole. And a molecule with two different poles is called Dipoles.
Some steps for considering the molecule are polar or nonpolar are:
- Draw the Lewis dot structure of a molecule.
- Find out the structure (shapes and Geometry) of the molecule.
- Calculate the net Dipole moment, if the net dipole moment is not zero then the molecule is polar if zero then the molecule is nonpolar.
- Dipole moment= charge * distance between atoms.
Frequently asked questions (FAQ):
- Lewis dot structure is a simple form representing the electrons around the individual atoms.
- Bond pairs represent the line between two atoms.
- Lone pairs are the electrons that are not participating in any bond formation that can either be used as it is or in resonance structures.
- Lewis dot structure is used to get the best configurations by satisfying the octet rule and formal charges and other important expectations of the molecules.