Lewis Dot Structure Generator

Lewis Dot Structure Generator Free
Lewis Dot Structure Generator N2

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Lewis structure of sulfate ion is drawn in this tutorial step by step. Total valence electrons concept is used to draw the lewis structure of SO₄^2-. In lewis structure of sulfate ion, there should be charges on several atoms due to -2 charge.

Steps for Writing Lewis Structures. Find the total valence electrons for the molecule. Explain How Examples: H 2 S, NCl 3, OH-Put the least electronegative atom in the center. Note: H always goes outside. Examples: NOCl, CF 2 Cl 2, HCN; Put two electrons between atoms to form a chemical bond. Examples: CH 4, NH 3, I 2; Complete octets on outside atoms.
Lewis Dot Structure. Lewis dot structures reflect the electronic structures of the elements, including how the electrons are paired. Lewis structures are a useful way to summarize certain information about bonding and may be thought of as “electron bookkeeping”. In Lewis dot structures each dot represents an electron.
To generate the Lewis dot structure, you have to follow the given steps: Find the total count of valence electrons to molecules. In this step, add the total count of valence electrons from all the atoms in a bit. Find the required count of electrons needed to make the atoms complete.

Sulfate ion | sulfate ion | SO₄^2-

Sulfate ion is one of the oxyanion of sulfur. Sulfur is at +6 oxidation state in SO₄^2-. Also, sulfate ion has a -2 charge.

Lewis structure of SO₄^2-

There are two S=O bonds and two S-O bonds in sulfate ion lewis structure. Sulfur atom is the center atom and four oxygen atoms are located around sulfur atom. There are no lone pairs in the last shell of sulfur atom.

Steps of drawing lewis structure of SO₄^2-

Following steps are required to draw the SO₄^2- lewis structure and they are explained in detail in this tutorial.

Find total number of electrons of the valance shells of sulfur and oxygen atoms
Total electrons pairs
Center atom selection
Put lone pairs on atoms
Check the stability and minimize charges on atoms by converting lone pairs to bonds.

Drawing correct lewis structure is important to draw resonance structures correctly

Total number of electrons of the valance shells of SO₄^2-

Both Sulfur and oxygen atoms are located at VIA group in the periodic table. So, oxygen and sulfur atoms have six electrons in their valence shell.

Total valence electrons given by sulfur atom = 6

There are four oxygen atoms in SO₄^2- ion, Therefore

Total valence electrons given by oxygen atoms = 6 *4 = 24

There are -2 charge on SO₄^2- ion. Therefore there are two more electrons which comes from outside to contribute to the total valence electrons.

Total valence electrons = 6 + 24 + 2 = 32

Total valence electrons pairs

Total valance electrons pairs = σ bonds + π bonds + lone pairs at valence shells

Total electron pairs are determined by dividing the number total valence electrons by two. For, SO₄^2- ion, Total pairs of electrons are 16.

Center atom of SO₃^2- ion

To be the center atom, ability of having greater valance is important. Therefore sulfur has the more chance to be the center atom (See the figure) because sulfur can show valance of 6. Maximum valnce of oxygen is two. So, now we can build a sketch of SO₄^2- ion.

Lone pairs on atoms

There are already four S-O bonds in the above sketch. Therefore only twelve (16-4 = 12) valence electrons pairs are remaining.
First, mark those twelve valence electrons pairs as lone pairs on outside atoms (on oxygen atoms). One oxygen atom will take three lone pairs following the octal rule (oxygen atom cannot keep more than eight electrons in its valence shell).
For four oxygen atoms, twelve electrons pairs are spent. Now all electron pairs are spent. There is no electron pairs to mark on sulfur atom.

Charges on atoms

After, marking electron pairs on atoms, we should mark charges of each atom. Each oxygen atom will get a -1 charge and sulfur atom get a +2 charge. The overall charge of ion is ( -1*4 + (+2) ) = -2.

Check the stability and minimize charges on atoms by converting lone pairs to bonds

When charges exist everywhere (on atoms) in the ion or molecule, that structure is not stable. We should try to reduce charges on atoms as much as possible. Now, we are going to learn how these facts will affect on sulfate ion.

Oxygen atoms should hold negative charges because electronegativity of oxygen is higher than sulfur. Otherwise, we can say, ability of holding negative charges is great in oxygen atoms than sulfur atoms.
The drawn structure is not a stable one because all atoms have charges.
Now, we should try to minimize charges by converting lone pair or pairs to bonds. So convert one lone pair of one oxygen atom to make a new S-O bond.
Now there is a double bond between sulfur atom and one oxygen atom. Now, there are three S-O single bonds between sulfur atom and other three oxygen atoms.

You see charges of atoms are reduced. Now, there is no charge in one oxygen atom and charge of sulfur atom is reduced from +2 to +1. So we have an stable ion than out previous one.

Can I reduce charges of atoms furthermore?

You should know, sulfur can keep more than eight electrons in its last shell. Therefore we can convert one more lone pair of another oxygen atom to a bond.

In new structure, charges of atoms are reduced than previous structure. Now there are no any charge on sulfur atom and two oxygen atom. Also, only two oxygen atoms have -1 negative charges. Now you understand this structure of SO₄^2- is more stable than previous structures. So, this structure has more chance to be the lewis structure of SO₄^2- ion.