Question

Explain Hybridization and it's Types and the conditions needed for it answer for 5 marks long

Answer 1

Scientist Pauling introduced the revolutionary concept of hybridization in the year 1931. He described it as the redistribution of the energy of orbitals of individual atoms to give new orbitals of equivalent energy and named the process as hybridisation. In this process, the new orbitals come into existence and named as the hybrid orbitals.

Rules for Calculating Hybridisation

The following rules are observed to understand the type of hybridisation in a compound or an ion.

Calculate the total number of valence electrons.

Calculate the number of duplex or octet OR

Number of lone pairs of electrons

Number of used orbital = Number of duplex or octet + Number of lone pairs of electrons

If there is no lone pair of electrons then the geometry of orbitals and molecule is different.

Types of Hybridisation

The following are the types of hybridisation:

1) sp – Hybridisation

In such hybridisation one s- and one p-orbital are mixed to form two sp – hybrid orbitals, having a linear structure with bond angle 180 degrees. For example in the formation of BeCl2, first be atom comes in excited state 2s12p1, then hybridized to form two sp – hybrid orbitals. These hybrid orbitals overlap with the two p-orbitals of two chlorine atoms to form BeCl2

2) sp2 – Hybridisation

In such hybridisation one s- and tow p-orbitals are mixed form three sp2– hybrid orbitals, having a planar triangular structure with bond angle 120 degrees.

3) sp3 – Hybridisation

In such hybridisation one s- and three p-orbitals are mixed to form four sp3– hybrid orbitals having a tetrahedral structure with bond angle 109 degrees 28′, that is, 109.5 degrees.



Studying the Formation of Various Molecules

1) Methane

4 equivalent C-H σ bonds can be made by the interactions of C-sp3 with an H-1s

2) Ethane

6 C-H sigma(σ) bonds are made by the interaction of C-sp3 with H-1s orbitals and 1 C-C σ bond is made by the interaction of C-sp3 with another C-sp3 orbital.

3) Formation of NH3 and  H2O molecules

In NH2 molecule nitrogen atom is sp3-hybridised and one hybrid orbital contains two electrons. Now three 1s- orbitals of three hydrogen atoms overlap with three sp3 hybrid orbitals to form NH3 molecule. The angle between H-N-H should be 109.50 but due to the presence of one occupied sp3– hybrid orbital the angle decreases to 107.80. Hence, the bond angle in NH3 molecule is 107.80.

4) Formation of C2H4  and C2H2 Molecules

In C2H4 molecule carbon atoms are sp2-hybridised and one 2p-orbital remains out to hybridisation. This forms p-bond while sp2 –hybrid orbitals form sigma- bonds.

5) Formation of NH3  and H2O  Molecules by sp2 hybridization

In H2O molecule, the oxygen atom is sp3 – hybridized and has two occupied orbitals. Thus, the bond angle in the water molecule 

Answer 2

Hey!
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★Hybridization ★
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→ What is Hybridization ?

=> It is the process of inter mixing of orbital with slightly different energies so as to re distribute their energies that results in the formation of new set of orbital with equivalent energies .


→ Types of Hybridization :


(i) sp - Linear Geometry ( BeCl2 )

(ii) sp² - Trignol Planar ( BCl3 )

(iii) sp³ - Tetra hedral ( CH4 )

(iv) sp³d - Trignol Bypiramidal ( PCl5 )

(v) sp³d² - Octahedral ( SF6 )

(vi) sp³d³ - Pentagonal Bipyramidal. ( IF7 )



→ Conditions for Hybridization :


(i) Only the orbital present in the valence shell are hybridized.

(ii) Promotion isn't necessary before hybridization .

(iii) The orbital undergoing hybridization should have a small energy difference .


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