SO32-Lewis structure, molecular geometry, hybridization and binding angle (2024)

The Lewis structure of Sulfite [So₃]^2-Ion consists of a sulfur (s) atom and three oxygen (O) atoms.

There are a total of 4 electrical density areas around the Central Atom in the Lewis structure of [So So SO₃]^2-.

Drawing of the Lewis structure of sulphite then₃^2-Is not that difficult.

Steps to draw the Lewis Dot structure of SO₃^2-

1. Count the total valence electrons in it₃^2-

The Lewis Dot structure in a molecule is called a simplified representation of all valence electrons that are present in it.₃^2-is thatCount the total valence electronsPresent in those elementatomas.

There are two different basic atoms present in the sulfite [so₃]^2-ion, mind (s) atom and oxygen (o) atoms.If you look through the periodic system with elements, you will notice that both sulfur (s) and oxygen (o) are placed in group VI A. So both sulfur and oxygen contain a total of 6 valence electrons in each atom.

• Total amountValence -electrons in sulfur= 6
• Total amountValence -Electrons in ILT= 6

[So₃]^2-Ion consists of 1 S atom and 3 O atoms.Thus, valence electrons are located in the Lewis-Stip structure of [SO SO₃]^2-= 1 (6) + 3 (6) =24 Valence electrons.

The turn here, however, is that [so₃]^2-Ion wears a negative (-2) load, which means that 2 extra valence electrons are added in this Lewis structure.

∴ Therefore, the total valence electrons are available to draw the Lewis Dot structure for [so₃]^2-= 24+2 =26 Valence -Electrons.

2. Select the central atom

Elektronegativity is defined as the power of an atom to attract a shared few electrons from a covalent chemical bond.With the more electronic atoms that surround it.

Because sulfur (s) less electronicgative than oxygen (o), an S-atom is placed in the middle of [So So SO₃]^2-Lewis structure, while the three o -atoms are in their environment, as shown below.

3. Connect the outer atoms with the central atom

Through this step of drawing the Lewis structure of a molecule or molecular ion, we must connect the outer atoms with the central atom with the help of a few straight lines.₃]^2-Ion, so all 3 oxygen atoms are connected to the central s -atom with the help of straight lines, as shown below.

Each straight line represents a single covalent bond that contains 2 electrons.

If we now count the total valence electrons used for this step from the 26 that are originally available, there are a total of 3 single bonds in the above structure.Trin 3.

• Total valence - electrons available - Electrons uses Tillstep 3= 26-6 = 20 Valence electrons.
• This means that we still have 20 valence electrons to meet the Lewis point structure of [SO in the Lewis₃]^2-.

4.Complete the octet of outer atoms

There are three O atoms as outdoor atoms in the Lewis structure of [So So SO₃]^2-.

Each S-o-binding already represents 2 electrons, so all three O atoms require 6 more electrons to complete their octet.So these 6 valence electrons are placed as 3 lonely couples on each O atom, as shown below.

5.Complete the octet in central atom

• Total valence electrons used up toTrin 4= 3 Single bindings + 3 (electrons placed round o-atom, shown as dots) =3 (2) +3 (6) = 24 Valence electrons.
• Total valence - electrons available - Electrons used up to step 4 =26-24 = 2 Valence electrons.

So these 2 valence electrons are now placed as a lonely pair on the central sulfur atom, as shown below.

The above structure shows that there are a total of 3 single bonds and 1 lonely pairs on the central S -atom, a total of 8 valence electrons in the area.Now have a complete Octet electronic configuration.

But the thing is, is this Lewis structure stable?Let's check it with the formal loading concept.

6. Check the stability of SO₃^2-Lewis structure using the formal charging concept

The less the formal charge of the atoms of a molecule, the better the stability of his Lewis structure.

The formal charging can be calculated using the formula below.

• Formal load = [Valens Electron- non-binding electrons ½ (binding electrons)]]]]

Now let's use this formula and the Lewis structure obtained inTrin 5To determine the formal loads on a sulfite [so₃]^2-ion.

Sulfur

• Valence -Electrons of sulfur = 6
• Glue electrons = 3 single bindings = 3 (2) = 6 electrons
• Non-binding electrons = 1 lonely pair = 2 electrons
• Formal charging = 6-2-6/2 = 6-2-3 = 6-5 = +1

For ILTATOM

• Valence -electrons of oxygen = 6
• Glue electrons = 1 single binding = 2 electrons
• Non-binding electrons = 3 lonely pairs = 3 (2) = 6 electrons
• Formal charging = 6-6-2/2 = 6-6-1 = 6-7 = -1

This calculation shows that a +1 formal charge is present on the central sulfur atom and that a -1 -formal charge is present on each of the three oxygen (O) atoms.

But as we said;The less the formal loads on the bound atom, the greater the stability of a Lewis structure.

So we can reduce the formal loads on the S and O atoms by transforming the lonely pair of electrons on a terminal O atom into a covalent bond between the central S-atom and Terminal O atom.

Let's see how it is done.

7. Minimize the formal loads on atoms by converting lonely couples into covalent bindings

A lonely pair of a terminal oxygen atom is converted into a covalent bond between the central S atom and the respective O atom as shown below.

Now there are a total of 2 single bonds and 1 double bond around the central S -atom.We can again control the stability of this Lewis structure using the formula of the formal charge.

Sulfur

• Valence -Electrons of sulfur = 6
• Binding electrons = 1 double binding + 2 single bindings = 1 (4) + 2 (2) = 8 electrons
• Non-binding electrons = 1 lonely pair = 2 electrons
• Formal charging = 6-2-8/2 = 6-2-4 = 6-6 = 0

To double oxygen atom

• Valence -electrons of oxygen = 6
• Glue electrons = 1 double binding = 4 electrons
• Non-binding electrons = 2 lonely pairs = 2 (2) = 4 electrons
• Formal charging = 6-4-4/2 = 6-4-2 = 6-6 = 0

For a few -bound oxatomas

• Valence -electrons of oxygen = 6
• Glue electrons = 1 single binding = 2 electrons
• Non-binding electrons = 3 lonely pairs = 3 (2) = 6 electrons
• Formal charging = 6-6-2/2 = 6-6-1 = 6-7 = -1

So here you can see that the formal loads are present on the central sulfur (s) atom and a terminal oxygen (O) atom are reduced to zero.

-1 + (-1) = -2, which accounts for a total negative 2 load on the sulfite [so [so.₃]^2-Ion.dit ensures that it is a correct and stable Lewis display for the sulfite [SO [[SO [₃]^2-Ion.₃]^2-The Lewis structure is closed in square hooks and a negative 2 load is located in the top right corner, as shown below.

If you are worried about the extra 2 electrons in the sulfur atom, which means more than Octet number electrons.Formation of chemical bonds as a result of the presence of a 3D -Sub -Shell in its atomic structure.

Another interesting fact to remember is that the actual structure of a sulphite [so₃]^2-Ion is a hybrid of the following resonance structures.

These resonance structures show that the formal loads are present on [SO₃]^2-Atoms are not stationary, they rather go from one position to another.

Finally, all the aforementioned resonance structures are entitled to resonance hybrid, which is the best possible Lewis structure of the sulphite [so₃]^2-ion.

Now that we have discussed everything about the Lewis structure in [SO₃]^2-, Let's continue to the next part of the article.

Also control -

• How do you draw a Lewis structure?
• Formal charging commemoration calculator
• Lewis -structuurcalculator

Sulfite [So₃]^2-Ion has a trigonal pyramidal shape and molecular geometry, while the ideal electron pargeetry of Ion is tetra -dry.₃]^2-.

The lonely pair -binding pair of electronic rejections distorts the geometry and form of molecular ion and ensures that it uses a different shape than its electronic geometry.

Molecular geometry of [SO₃]^2-

Sulfite [So₃]^2-Ion has oneTrigonal piramidalMolecular geometry and shape.There is a lonely pair of electrons present on the central sulfur atom in Sulfite.

This repellent effect distorts the shape of the molecule and ensures that it uses a trigonal pyramidal shape.

An important point to note is that the molecular geometry or the shape of a molecule or a molecular ion is highly dependent on the different number of binding and lonely pairs present on the central atom.

However, the ideal electron pargeometry only depends on the total number of electron pairs that is present on the central atom, whether it is a binding pair or a lonely pair.

Let's see how this concept is used for the sulfite [so₃]^2-ion.

Electron geometry of [SO₃]^2-

According to Valence Shell, the disposal of electron pairs (VSEPR) of chemical bond is the ideal electron geometry of a molecule or a molecular ion that contains a total of 4 electronist density areas around the central atomet retreater.

In the sulfite [so₃]^2-Ion, there are 2 single bonds, 1 double bond and 1 lonely pairs on the central sulfur atom that a total of 4 voters density areas.TetraëdrischElectronpar -geometrie.

A simple way to find the shape and geometry of the molecule is to use the AXN method.

AXN is a simple formula for displaying the number of atoms bound to the central atom in a molecule and the number of lonely couples on it.

It is used to predict the geometry or the shape of a molecule using the VSEPR concept.

AXN setup for [so₃]^2-Molecular ion

• A in the AXN formula represents the central atom.₃]^2-Ion, sulfur is present in the middle, so a = sulfur.
• X indicates the atoms to the central atom.₃]^2-, Three oxygen (O) atoms are bound to central S, so x = 3.
• N stands for the lonely pairs that are present in the central atom₃]^2-There is a lonely pair on central sulfur, so n = 1.

DUS AXN -generic formula dead [zo₃]^2-Ion is ax₃N.

Now you can view the VSEPR graph below.

According to the above VSEPR diagram, the ideal electron geometry of a molecule or a molecular ion with ax₃An generic formula is Tetraërian, while the molecular geometry or form is the trigonal pyramidal that we have already noticed [so₃]^2-ion.

Hybridization of [SO₃]^2-

Sulfite [So₃]^2-Ion has SP³Hybridization.

The electronic configuration of a sulfur (s) atom is 1s²2s²2P⁶SC²3P⁴.

The electronic configuration of oxygen (O) atom is 1s²2s²2P⁴.

During chemical binding, they are accompanied by 3P electrons of sulfur, and one of these electrons switches to an empty 3D atoom Orbitaal from sulfur.³Hybrid orbital.A Elke Sp³Hybrid Orbitaal has a character of 25 % and a character of 75 % P.

Three of the four SP³Hybrid orbitals each contain a single electron while the fourth SP³Hybrid Orbital contains paired electrons.These paired electrons are located like a lonely pair on the central atom in the sulfite [SO.₃]^2-ion.

SP³Hybrid orbitals that contain individual electrons form S-o Sigma (σ) bindings with p-orbitals of oxygen from SP³-p overlap each other on each side of [so₃]^2-ion.

The remaining sp³Hybrid Orbitaal from sulfur forms a Sigma (σ) bond with a SP²Hybrid orbital of oxygen in s = o double binding.

The non -Hybridized D Orbital of sulfur overlaps with the inhybridated P orbital of this oxygen to form the required PI (π) binding in s = O double bond of the sulfur.

See the figure below to understand these concepts more clearly.

A shortcut to find the hybridization that is present in a molecule or molecular ion can be used by the steric number against the table below.₃]^2-is 4, so it has SP³Hybridization.

The steric number of central sulfur in SO₃^2-is 4, so it has SP³Hybridization.

SO₃^2-Bindingshoek

The ideal bonding angle of a Tetrahedral molecule is 109.5 °, but in the sulphite [so₃]^2-Ion, the lonely pair that is present on the central sulfur atom, distorts the shape and geometry of molecular ion.It takes on a triangular pyramidal shape and consequently the o-o-o-o-o-binding angle of the ideal 109.5 ° to around 1006 ° drops.

Although it is expected to be an S = O-binding stronger and shorter than an S-o-binding₃]^2-its equivalent and equal to 151 pm.

Also check:-How do you find a binding angle?