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Phosphite Ion (Po3-3); How to Draw Lewis Structure, Molecular Geometry and Hybridization

This article is about the Lewis structure of Phosphite Ion (Po3-3), the molecular geometry of Po3-3, and the formal charge present on Po3-3.


What is Lewis’s structure, and why is it essential to study Lewis’s structure in chemistry?

The valence shell electrons of a molecule are depicted in a Lewis Structure, which is a simplified representation. It’s used to illustrate how electrons in a molecule are distributed around specific atoms.


When two atoms are bonded, electrons are shown as “dots” or as a line between them. The main goal of Lewis Structure is to find the “optimal” electron configuration, which requires that the octet rule and formal charges be maintained.


Famous scientist Gilbert N. Lewis initially proposed the Lewis structure in his journal “The Atom and the Molecule” in 1916.


The Lewis structure in chemistry is essential because it can predict the number of bonds, nonbonding electrons, and bonding electron structure.


Lewis structure does not try to explain the molecular shape, bond formation, or electron sharing between atoms. It is the most basic and limited explanation of the electrical structure.


Introduction of Phosphite Ion (Po3-3)


PO3–3 is known as a phosphite ion. Phosphite (3-) is a trivalent inorganic anion formed by the removal of all three protons from phosphorous acid. It is a trivalent inorganic anion and a phosphate ion. It is a conjugate base. It is a black granular powder.


Valence Electrons

Valence electrons are the electrons that are present in an atom’s outermost shell.  To study the Lewis structure of any molecule, it is essential to understand the electrons present in the valence shell.


Lewis Structure of Phosphite Ion (Po3-3)


Lewis Dot Structure is a graphical representation of the atoms that helps us to understand the molecule’s bond forms and electron arrangement.


To learn about the Lewis structure of PO3-3phosphite ions, we must learn about the Lewis diagrams of the atoms involved. Phosphorus belongs to the V group of elements. It has five electrons in its valence shell. whereas O belongs to the VI group of elements.





Steps to remember while drawing the Lewis Structure:

These are the following steps to remember while drawing the Lewis structure in chemistry.

  • Determine how many electrons are present in total in the valence shells of the oxygen and phosphorus atoms.

  • Both total lone pairs and bond pairs exist.

  • Choosing the center atom

  • Draw lone pairs.

  • Mark charges at atoms.

  • Check the stability and reduce atom charges by converting lone pairs to bonds in order to obtain the perfect Lewis structure.

Steps to Draw the Lewis Structure of the Phosphite Ion (Po3-3)


Phosphite Ion (Po3-3); How to Draw Lewis Structure, Molecular Geometry and Hybridization

Calculate the total number of electrons in the valence shells.


We must calculate the valence electrons present in PO3–3 to draw the Lewis structure of PO3–3. Five valence electrons are present in phosphate, while six electrons are present in each oxygen atom. So, we can say that three oxygen atoms have 18 valence electrons.

Valence electrons of oxygen atom= 6

Valence electrons of phosphorus atom= 5

Due to the -1 charge, one more electron will be added.

So,

5+18+3 = 26.


  1. Choose the center atom.

The most electropositive element will be the central atom. In the case of phosphite ions, phosphorus is more electro-positive than oxygen. So, the central will be the central atom.

A Sketch of PO3–3


2. Mark lone pairs on atoms.

The next step after choosing the central atom is to draw lone pairs on the atoms of a molecule. To draw lone pairs, it is crucial to remember how many total electrons are present. So, in the case of the phosphate ion (Po3-3). 

, six electrons are participating in a double bond between phosphorus and each oxygen atom.  


3. Mark and stabilize charges on atoms.

The following formula can be used to calculate formal charges:

The formal charge is equal to valence electrons minus nonbonding electrons minus 1/2 of the bonding electrons.

Formal charge = 5 – 0 – 1/2 (8) = 1 for phosphorus atom.

Formal charge = 6 – 4 – 1/2 (4) = 0 for double bonded oxygen atom.

Formal charge = 6 – 6 – 1/2 (2) = -1 for single bonded oxygen atom.

Formal charge = 6 – 6 – 1/2 (42) = 0 for double bonded oxygen atom.

The positive and negative charges on phosphorus and oxygen atoms cancel each other out. The oxygen atom only has one remaining negative charge, indicating that the formal charge of the Phosphite Ion (Po3-3) molecule is -1.

  • Non-bonding electrons

Those electrons do not participate in any bond formation.

  • Bonding electrons

Those electrons that are participating in bond formation are known as bonding electrons.


Importance of Lewis Structure in Chemistry


The Lewis structure of any molecule is important because:

  • It allows us to predict how and how many bonds it will form. This understanding will eventually allow us to identify molecule forms and chemical characteristics.


Molecular Geometry and Shape of the Phosphite Ion (Po3-3)


Phosphite Ion (Po3-3); How to Draw Lewis Structure, Molecular Geometry and Hybridization

Molecular Geometry of Phosphite Ion (Po3-3)


Molecular geometry or molecular structure means the three-dimensional structure, shape, or arrangement of atoms in a molecule. Molecular geometry helps us determine its polarity, reactivity, phase of matter, color, magnetism, and biological activity.


The molecular geometry of the PO3-3 is trigonal pyramidal. In the Lewis structure of PO3-3, there are three oxygen atoms with a single bond and they spread far away from each other, while there is a phosphorus atom in the center with one lone pair on it which pushes everything down. That’s why it has a trigonal pyramidal shape. The bond angle is about 109.5 degrees.


Molecular Structure of Phosphite Ion (Po3-3)


  • The geometry of Po3-3 molecule by AXN notion

The basic geometry of the molecule or ion will be described using the AXN notation, where A represents the core atom phosphate in this case, and X represents the terminal atoms (oxygen) that are bonded to the central atom. The number of lone pairs is indicated by the letter “n. “

The electron geometry is tetrahedral while the molecular geometry of the PO3–3 is trigonal pyramidal. The bond angle of PO3–3 is 109.5 degrees.

The polarity of compounds and factors affecting polarity .


The polarity of Phosphite Ion (Po3-3)


Phosphite Ion (Po3-3); How to Draw Lewis Structure, Molecular Geometry and Hybridization


Because of its shape, PO3–3 is a polar molecule.


Factors affecting polarity

  • Electronegativity:

The stronger the atom’s ability to attract bound electrons, the higher its electronegativity. As a result, the difference between the electronegativity of atoms is precisely proportional to the polarity of a molecule.

  • Dipole Moment:

The dipole moment is a measurement used to determine the level of polarity. A molecule’s polarity increases as its dipole moment increase. A molecule’s polarity and dipole moment are proportional.

  • Geometrical Shape:

 The geometrical shape of molecules has a significant role in defining their polarity. A molecule’s dipole moment is zero for symmetrical molecules. A nonpolar molecule is formed when a molecule has a polar bond because the dipole moments of the molecules cancel each other out.


Hybridization of Phosphite Ion (Po3-3)


In the Lewis structure of PO3–3, P is the central atom in PO3–3. It has one lone pair and forms three sigma bonds with each O atom (double and triple bonds are counted as one sigma bond). The molecule Sp3 is therefore hybridized.


When hybridization process occurs?


The hybridization process occurs when the atomic orbital of a similar energy mix overlaps like that of an s orbital with a p orbital or a s orbital with a d orbital.


Within a molecule, energy redistribution occurs among similar energy orbitals of individual atoms, resulting in the creation of new hybrid orbitals of equivalent energy.


Characteristics of Phosphite Ion (Po3-3)

Chemical formula

PO3–3

Boiling point

280 °C (536 °F)

Melting point

 44.1 °C (111.4 °F)

Molecular weight

78.972

Density

1.82 gram/cm3 at 20 °C (68 °F)

Chemical Characteristics of Phosphite Ion (Po3-3)


  • Phosphite (3-) is a trivalent inorganic anion formed by the removal of all three protons from phosphorous acid.

  • It is a trivalent inorganic anion and a phosphate ion.

  • It is a conjugate base.

  • It is a black granular powder

  • It has a pungent odour

  • It is highly toxic and corrosive.


Conclusion

The article is about the Lewis structure of PO3–3and its importance in chemistry. Phosphite Ion (Po3-3) is known as a phosphite ion. Phosphite (3-) is a trivalent inorganic anion formed by the removal of all three protons from phosphorous acid.


It is a trivalent inorganic anion and a phosphate ion. It is a conjugate base. It is a black granular powder. Phosphite Ion (Po3-3) can be hazardous to health because of its explosive and reactive nature.


 The electron geometry is tetrahedral while the molecular geometry of the PO3–3 is trigonal pyramidal. The bond angle of Phosphite Ion (Po3-3) is 109.5 degrees. Furthermore, the hybridization of PO3–3 is sp3. Finally, the presence of a net dipole moment, mainly due to a lone pair of electrons on the phosphate makes the PO3–3   molecule polar. Different factors can affect the polarity of the molecule or atom.


FAQs


PO3–3 is polar or non-polar? And Why?


The separation of electric charge that results in one negatively charged and one positively charged end is known as polarity. Because of the difference in the electronegativity values of the involved atoms, this charge separation causes a net dipole moment on the overall molecule.PO3–3 is a polar molecule because of its asymmetric structure, which causes an unequal charge distribution around atoms, making it harder to cancel out the dipole leading to a net dipole moment for it. As a result, PO3–3 has a polar structure.


List down the important Steps to drawing Lewis Structure.


These are the following steps to remember while drawing the Lewis structure.

  • Determine how many electrons are present in total in the valence shells of the oxygen and phosphorus atoms.

  • Total electron pairs and lone pairs exist.

  • Choosing the center atom

  • Draw lone pairs.

  • Mark charges on atoms.

  • Check the stability and reduce atom charges by converting lone pairs to bonds in order to obtain the perfect Lewis structure.


Who proposed the Lewis structure?


Famous scientist Gilbert N Lewis initially proposed the Lewis structure in his journal “The Atom and the Molecule” in 1916. The Lewis structure in chemistry is essential because it can predict the number of bonds, nonbonding electrons, and bonding electron structure.




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