5 Steps to Draw SIH4 Lewis Structure,Hybridization (Solved!)

Silane (SiH4) has a silicon (Si) atom at its center with 4 valence electrons, bonded to four hydrogen (H) atoms, each contributing 1 electron. The Lewis structure shows four single Si-H bonds, with 8 bonding electrons and no lone pairs on silicon. Silane adopts a tetrahedral geometry, with bond angles of approximately 109.5°, typical for sp³ hybridization. The molecule is nonpolar due to its symmetrical shape, despite the slight electronegativity difference between Si (1.90) and H (2.20). This structure is key to understanding its reactivity, particularly its hydrolysis to form SiO2 and H2.

SiH4 is also called silane or monosilane, it is a colorless flammable and poisonous gas with a strong pungent odor. SiH4 reacts with the oxidizing agents when we inhale silane it is very toxic it affects the skin, eyes, and mucous membrane.  SiH4 molecule contains a single silicon atom surrounded by four hydrogen atoms.

SIH4 lewis structure
SIH4 lewis structure

Let us see the following topics in this article

HOW to draw Lewis structure for SIH4

 While making the Lewis structure of the SiH4 molecule the first thing to remember is how many valence electrons of all the atoms in the molecule take part in chemical bonding.  

When we draw the Lewis structure of SiH4 we always know the number of electrons present in the outermost shell of the atoms which are included in the Lewis structure.

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Lewis structure of SiH4

SIH4 lewis structure lone pairs

In the SiH4 molecule, the central atom silicon atom contains four valence electrons while the Hydrogen atom has one valence electron so in silane there are four hydrogen atoms attached to silicon hence the total number of eight valence electrons are present in the SiH4 molecule.   SiH4=[ 4+ (1×4)] = 8.

The silicon atom is a less electronegative atom than hydrogen hence it places in the centre, and four hydrogen atoms are lying around the silicon atom.

SIH4 lewis structure octet rule

For a stable Lewis structure, all the atoms in the molecules present must satisfy the octet rule, octet rule states that to attain a stable configuration valence shell of an atom contains eight electrons which resemble an electronic configuration of the nearest noble gas.

In the SiH4 molecule, the hydrogen atom requires only one electron to complete its octet while the silicon atom requires four electrons to complete its octet and become stable.

silicon and hydrogen atom shares one electron with each other and completes their octet, hydrogen having two valence electron and silicon having eight valence electrons in this way they complete their octet.  

SIH4 lewis structure formal charges

If in any molecule there is a difference between the electronegativity of both atoms then it has some formal charge on it, but in the SiH4 molecule, there is no considerable difference in electronegativity hence the formal charge on the SiH4 molecule is zero.

SIH4 hybridization

Hybridization is a process in which the atomic orbitals of both the atoms in a molecule come together and combine with each other to form a hybrid orbital by direct overlapping sigma bond is formed while side to side parallels overlap forming a pi bond.

In SiH4 molecule the electronic configuration of silicon is,

Si: 1s2 2s2 2p6 3s2 3p2

Si: [Ar] 3s2 3p2

sih4 lewis structure
Hybridized orbital of SiH4

From the above diagram, the s orbital and three p orbital come together and combine to form 4 hybridized 3p3 orbitals these 4 hybrid orbitals form four sigma bonds with four hydrogen atoms. Therefore, the hybridization for Si is sp3 in SiH4.

SIH4 polar or nonpolar

The polar or nonpolar nature of a molecule depends upon the difference between the electronegativity value of the atom which is present in the molecule. In the SiH4 molecule, there is not very much difference in electronegative values. So Silane molecule is non-polar in nature. But silicon and hydrogen atom have a partial  positive and negative charges on them.

SIH4 lewis structure shape

According to VSEPR theory, the molecular geometry depends upon the central atom of a molecule, surrounding atoms of a molecule, and lone pairs on the central atom, so in the case of the SiH4 molecule central atom is silicon.

which is surrounded by four hydrogen atom and silicon has no lone pair of electrons hence it shows AX4E type geometry according to VSEPR theory molecule which has four surrounding atoms with no lone pair shows tetrahedral geometry. So, silane (SiH4) shows tetrahedral geometry with a bond angle of 109o and Si-H bond length is 1.4798 Ao

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tetrahedral Lewis structure of SiH4 wikipedia

SIH4 lewis structure resonance

Resonance is a chemical phenomenon, in which all properties of molecule are not able to explain with a single structure. There are many canonical structures involved. But not every molecule can exhibit resonance.

SiH4 lewis structure does not exhibit resonance because there is no delocalization of electrons and there is the presence of single bonds. So there is no movement. SiH4 also has not lone pair of electron . Hence there are no resonating structures of the SiH4 lewis structure

Frequently asked question

How many valence electrons does SiH4 have?

Answer: In the SiH4 molecule, the central atom silicon atom contains four valence electrons while the Hydrogen atom has one valence electron so in silane there are four hydrogen atoms attached to silicon hence the total number of eight valence electrons are present in the SiH4 molecule.

How many lone pairs does SiH4 (silane) have?

Answer: Silane has one silicon atom attached with four hydrogen atom, there are four single bond around central silicon atom, and no lone pair of electrons on both the atoms.

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