Chapter 5, Problem 1E

Explain how σ and $\pi$ bonds are similar and how they are different.

Interpretation Introduction

Interpretation:

The similarity and difference between s and p bonds is to be explained.

Concept Introduction:

• There are two types of bonds that are formed between the atoms-

a) Covalent bond- the bond formed by the sharing of electrons between the atoms.

b) Ionic bond- When atoms gain/loss electrons and become ions, the electrostatic attraction between the oppositely charged ions is known as ionic bond.

• Electron in atoms occupy atomic orbitals while in molecule, electrons occupy molecular orbitals. These molecular orbitals are formed by the combination of the atomic orbitals and they can be bonding molecular orbitals and ant-bonding molecular orbitals.
• The process of mixing of atomic orbitals of similar energy to produce new molecular orbitals of equivalent energy is known as hybridization.

Answer to Problem 1E

Similarity-They both are chemical covalent bonds and are formed by the overlapping of the atomic orbitals.

Differences-

s- bond	?-bond
Formed by the axial overlap of the atomic orbitals.	Formed by the side-ways overlap of the atomic orbitals.
It can be formed by the overlap of s-s, s-p or p-p orbitals.	It can only be formed by the overlap of p orbitals
Oriented along the internuclear axis.	Oriented perpendicular to the internuclear axis.
Exists independently.	Exist along with sigma bond.
Stronger than pi-bond.	Weaker than sigma bond.
More reactive.	Less reactive.
Determines the shape of the molecule.	Does not determine the shape of the molecule.

Explanation of Solution

• Sigma (s) bonds- It is a type of covalent bond which is formed by the end to end overlapping of the atomic orbitals of the atoms involved in bonding.

  

• Pi (p)bonds -It is a type of covalent bond which is formed by the side wise overlapping of the atomic orbitals of the atoms involved in bonding.

  

Therefore, differences between sigma and pi bonds are-

s- bond	?-bond
Formed by the axial overlap of the atomic orbitals.	Formed by the side-ways overlap of the atomic orbitals.
It can be formed by the overlap of s-s, s-p or p-p orbitals.	It can only be formed by the overlap of p orbitals
Oriented along the internuclear axis.	Oriented perpendicular to the internuclear axis.
Exists independently.	Exist along with sigma bond.
Stronger than pi-bond.	Weaker than sigma bond.
More reactive.	Less reactive.
Determines the shape of the molecule.	Does not determine the shape of the molecule.

Conclusion

However, the only similarity between these two are that they both are chemical covalent bonds and are formed by the overlapping the atomic orbitals, and the main difference is that sigma bond is formed by the axial overlap of the atomic orbitals, whereas, pi bond is formed by the sideways overlapping of atomic orbitals.