SH2 Lewis Structure: Drawings, Hybridization, Shape, Charges, Pair And Detailed Facts

Electron dot structure gives idea about the planer structure of a molecule. This article will discuss about sh2 lewis structure and the method of drawing it.

Outer orbit electrons are shown in the sh2 lewis structure. So from this lewis structure we can conclude the facts about the hybridization, shape and other things about the molecule.

How to draw lewis structure for SH2

SH2 Lewis structure gives information about outer most orbit electrons of the involved atoms. These electrons are responsible for chemical properties of the molecule.

To draw Hydrogen Sulfide lewis structure, the atomic symbols of atoms that are ‘S’ for Sulfur and ‘H’ for Hydrogen are written. The outer orbit electrons of an atom are shown by dot symbols around that particular atom in the sh2 molecule.

Sulfur is a ‘group 16’ element and Hydrogen is a ‘group 1’ element in the Periodic table.

Electronic configuration of Sulfur: [Ne] 3s2 3p4. Electronic configuration of Hydrogen: [Ne] 1s1. So outer orbit electrons of Sulfur atom are six and that of Hydrogen atom is one.

Total number of the outer orbit electrons are {6 + (1×2)} =8. Hence four pairs of electrons take part in SH2 molecule formation.

Less electronegative atom becomes the central atom in the molecule. So Hydrogen atom should be the central atom. But it should have minimum two electrons to be a central atom which is not possible for Hydrogen atom.  Sulfur becomes the central atom in the SH2 molecule.

Two Hydrogen atoms form sigma bonds (single bond) with Sulfur atom. Four electrons (two pairs of electrons) take part in bond formation. Central atom Sulfur has four unshared electrons over it.

Straight lines are used for showing the bonding electrons of the sigma bond between the Sulfur and Hydrogen atom.

SH2 lewis structure shape

SH2 lewis structure shape can be derived from the VSEPR theory (Valence shell electron pair repulsion theory).

This theory states that the molecule will be stable if there is minimum repulsion between the outer most orbit electrons. So the outer most orbit electrons arrange themselves accordingly.

This theory assumes that, the unshared electrons (lone pair) remains in control of the belonging atom with more space than the bonding electron cloud. The repulsion between lone pair- lone pair electron is greater than the repulsion between bond pair- bond pair electrons.

Hence if a central atom contains nonbonding electron cloud, the geometry of the molecule disturbed for the repulsion.

Hybridization of atomic orbital of the central atom Sulfur is sp3 in the molecule. For this the geometry of the molecule should be tetrahedral. But Sulfur atom has four unshared electrons.

For the repulsion between the two nonbonding electron pair cloud, the structure of the molecule becomes disturbed. To minimize the repulsion the shape of the molecule become “V” liked shape.

sh2 lewis structure
SH2 lewis structure shape

SH2 lewis structure formal charges

The formal charge of an atom is calculated assuming that all atoms of the molecule having the same electronegativity.

Formal charge of a atom in a molecule = (total number of outer shell electrons – nonbonding electrons – (1/2×bonding electrons))

From the Periodic table group numbers of the atoms, we know that outer most orbit electrons of Sulfur are six and that of Hydrogen is one. Sulfur atom has four unshared electrons whereas Hydrogen atom has no such type of electrons in the molecule.

Formal charge for the central atom Sulfur is = {6- 4- (1/2×4)} = 0.

Formal charge for the each Hydrogen atom is = {1- 0- (1/2×2)} = 0.

As the individual atoms in the molecule have zero formal charge, hence the formal charge of the molecule, SH2 is also Zero.

SH2 lewis structure lone pairs

In a molecule lone pairs are the electrons which don’t take part in the bonding formation with the other atoms. These only concentrate over the parent atom.

In Sh2 lewis structure, there total eight outer shell electrons participate. Among these electrons only four electrons make bond between the central atom Sulfur and the two Hydrogen atoms. Remaining four electrons are unshared electrons.

The four nonbonding electrons belong to the 3s and 3p orbitals of the Sulfur atom.

SH2 hybridization

In the Valence bon theory, concept of hybridization is very much important as it can describe the shape of molecule.

In the concept of Hybridization, atomic orbitals are mixing up. The new hybridized orbital differs with respect to the component orbitals in energy, shape. In the Hydrogen Sulfide molecule, we only consider the hybridization of the central atom, Sulfur. From this we can understand the shape of the molecule.

In the ground state of Sulfur atom, it has two unpaired electrons in 3p orbital. So it can form two bonds with another two atoms with these two unpaired electrons. Beside this it has two pairs of electrons, one is in 3s orbital and another one is in 3p orbital. These concentrate over the atom as lone pairs of electron.

After hybridization the overlap of the orbitals become greater in bond formation. Hence mixing up of orbitals occurs.

The new hybridized orbital is sp3 in nature. This sp3 hybridized orbital overlaps with the Hydrogen atomic orbital 1s to form molecule.

SH2 lewis structure resonance

When an atom contains nonbonding electrons, these can be able to delocalize into another atom of the molecule. In this way, resonance structure of a molecule form.

To delocalization of the electrons the accepter atom must have vacant orbital. In the SH2 molecule Hydrogen atom has no vacant orbital that it can accept electron from Sulfur atom. Hence no resonance structure can be formed.

SH2 lewis structure octet rule

The electronic stability of a molecule lewis configuration can be explained by this Octet rule.

All main group elements of the Periodic table like to have full filled outer orbitals with eight electrons. This preference is called the Octet rule. Only Hydrogen atom can have highest two electrons in the 1s orbital. This is because it has only ‘K’ orbit which contains only “s” orbital.

Sulfur has six electrons in the outer orbit 3s and 3p, as a ‘group 16’ element. It prefers two more electrons to be like nearest Noble gas Argon. Hydrogen atom has only one electron in the 1s orbit, so it accepts that electron from Sulfur atom.

 In this way both cover eight electrons in the outer most orbits. For this the molecule becomes lower in energy. It gives the molecule stable structure like the noble gases have.

SH2 polar or nonpolar

Polarity is a physical property of a molecule if it has a net dipole moment. Bond dipole moment (µ) = separated charge (δ) × distance between charge(r).

In the Hydrogen Sulfide molecule, electro-negativity of Sulfur (S) is 2.58 and that of Hydrogen is 2.2 on the Pauling scale. As the atoms of the molecule have slightly difference in electro-negativity, an unequal charge separation occurs in the molecule. Also for the bent structure, sh2 becomes slightly polar in nature.

For the slight difference between electro-negativity, unequal charge separation occurs. This gives a direction of dipole moment. If these direction vectors can’t neutralize each other, a net dipole moment generates.

The geometry of the molecule should be tetrahedral. From VSEPR theory we know that lone pair- lone pair repulsion is greater than bond pair- bond pair repulsion. For the repulsion between nonbonding electron pairs cloud of the central atom Sulfur, the shape of the molecule becomes “V”- shaped.

sh2 lewis structure
polarity of the SH2 lewis structure

For the distorted V- shape, the direction of dipole moments for electro-negativity, can’t cancel out each other. Hydrogen Sulfide become a slightly polar molecule.

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