Hybridization Worksheet With Answers - Chapter 1 printable pdf download

Hybridization Worksheet With Answers - Chapter 1

Chapter 1

Hybridization

1.1

INTRODUCTION

The atomic number of carbon is six. Its electronic configuration in the ground state may be written as

p . According to this configuration, there are two half-filled orbitals (the volume

of the space, where probability of finding an electron is maximum, is termed as an orbital). Therefore,

carbon should be bivalent. But, it is an established fact that carbon is tertravalent. Hence, in order to

account for tetra-covalency of carbon, it is suggested that one electron jumps from 2s orbital to 2p

orbital. The energy required for this jump is 96 kcal/mole, which is rationalized by arguing that the

energy released when two additional bonds are formed would more than compensate for that required

to excite the electron to a vacant 2p

orbital. Thus, electronic configuration of carbon in the excited

state may be written as 1s

p . Although this explains well the tetravalency of carbon,

but it also predicts that carbon atom forms two types of bonds, three of one type (those formed from

three 2p orbitals) and 4

of another type (that formed from 2s orbitals), since s and p orbitals are

different with respect to energy and shape. However, it is a well-established fact that all the four

valencies of carbon are equivalent (A simple proof of this fact is that the chlorination of methane gives

only one monochloromethane). Therefore, it has been suggested that all the four orbitals mix together

to form new orbitals of equivalent energy. This is the basic concept of hybridization.

Hybridization may be defined as the phenomenon of mixing of atomic orbitals of nearly

equivalent energy, involving redistribution of energy, to form new orbitals of equal energy

known as hybrid orbitals. The number of hybrid orbitals is equal to the number of the orbitals

hybridized. The properties of the hybrid orbitals are in between the properties of the orbitals

which are hybridized.

The number of p-orbitals, which take part in hybridization, is called the hybridization index

and is designated by ‘m’. The mathematical relationship between hybridization index and the bond

angle (α α α α ), formed between hybrid orbitals, is as follows:

−

cos

Hybridization Worksheet With Answers - Chapter 1