Name: All About Molecular Orbital Theory
Uploaded: 2019-07-19
Duration: 9 min 36 s
Description: The molecular orbital theory revolutionised the study of chemical bonding by approximating the states of bonded electrons. Let's learn more about this theory.

Question

Draw diagrams showing the formation of a double bond and a triple bond between carbon atoms in

C_{2} H_{4}

and

C_{2} H_{2}

molecules.

Accepted Answer

The electronic configuration of $C$ -atom in the excited state is:
${}_{6}C = 1 s^{2} 2 s^{1} 2 p_{x}^{1} 2 p_{y}^{1} 2 p_{z}^{1}$

$C_{2} H_{4}$ :
In the formation of an ethane molecule $(C_{2} H_{4})$ , one $s p^{2}$ hybrid orbital of carbon overlaps $s p^{2}$ hybridised orbital of another carbon atom, thereby forming a $C - C$ sigma bond.
The remaining two $s p^{2}$ orbitals of each carbon atom form a $s p^{2}$ sigma bond with two hydrogen atoms. The unhybridised orbital of one carbon atom undergoes sidewise overlap with the orbital of a similar kind present on another carbon atom to form a weak $π$ -bond.
(a)

(b)

(c)

(d)

$C_{2} H_{2}$ :
In the formation of $C_{2} H_{2}$ molecule, each $C$ –atom is $s p$ hybridised with two $2 p$ -orbitals in an unhybridised state.
One $s p$ orbital of each carbon atom overlaps with the other along the internuclear axis forming a $C - C$ sigma bond. The second $s p$ orbital of each $C$ –atom overlaps a half-filled $1 s$ -orbital to form a $σ$ bond.
The two unhybridised $2 p$ -orbitals of the first carbon undergo sidewise overlap with the $2 p$ orbital of another carbon atom, thereby forming two $p i (π)$ bonds between carbon atoms. Hence, the triple bond between two carbon atoms is made up of one sigma and two $π$ -bonds.

Draw diagrams showing the formation of a double bond and a triple bond between carbon atoms in $C_{2} H_{4}$ and $C_{2} H_{2}$ molecules.

Important Questions on Chemical Bonding and Molecular Structure

Learn and Prepare for any exam you want !

Draw diagrams showing the formation of a double bond and a triple bond between carbon atoms in C2H4 and C2H2 molecules.

Important Questions on Chemical Bonding and Molecular Structure

Learn and Prepare for any exam you want !

Draw diagrams showing the formation of a double bond and a triple bond between carbon atoms in $C_{2} H_{4}$ and $C_{2} H_{2}$ molecules.