IB Chemistry Topic S2.2.15 Sigma and Pi Bonds Revision Notes (HL)

IB Chemistry Topic S2.2.15 Sigma and Pi Bonds Revision Notes (HL) | RevisionDojo

Written by official IB examiners

Sigma (σ) and Pi (π) Bonds: Formation and Identification

How Sigma Bonds Form

Definition

Sigma bonds

Sigma bonds form when atomic orbitals overlap head-on along the bond axis, the imaginary line connecting the nuclei of two bonded atoms.

This direct overlap creates a region of high electron density between the nuclei, resulting in a strong electrostatic attraction that holds the atoms together.
Types of Orbitals Involved:
1. Two s orbitals (e.g., in H₂)
2. One s orbital and one p orbital (e.g., in HCl)
3. Two p orbitals oriented end-to-end (e.g., in Cl₂)

Characteristics of Sigma Bonds

Electron Density: Concentrated along the bond axis.
Strength: Sigma bonds are generally stronger than pi bonds due to the direct overlap of orbitals.
Flexibility: Single bonds (which are sigma bonds) allow free rotation around the bond axis.

Example

In a hydrogen molecule (H₂), each hydrogen atom contributes one electron in its 1s orbital.
These two 1s orbitals overlap directly along the bond axis, forming a sigma bond.
This bond is responsible for holding the two hydrogen atoms together.

Nice try, unfortunately this paywall isn't as easy to bypass as you think. Want to help devleop the site? Join the team at https://revisiondojo.com/join-us. exercitation voluptate cillum ullamco excepteur sint officia do tempor Lorem irure minim Lorem elit id voluptate reprehenderit voluptate laboris in nostrud qui non Lorem nostrud laborum culpa sit occaecat reprehenderit

Definition

Paywall

(on a website) an arrangement whereby access is restricted to users who have paid to subscribe to the site.

anim nostrud sit dolore minim proident quis fugiat velit et eiusmod nulla quis nulla mollit dolor sunt culpa aliqua

Lorem ipsum dolor sit amet, consectetur adipiscing elit. Sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.

Duis aute irure dolor in reprehenderit

Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.

Note

Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam quis nostrud exercitation.

Excepteur sint occaecat cupidatat non proident

Nemo enim ipsam voluptatem quia voluptas sit aspernatur aut odit aut fugit, sed quia consequuntur magni dolores eos qui ratione voluptatem sequi nesciunt. Neque porro quisquam est, qui dolorem ipsum quia dolor sit amet, consectetur, adipisci velit.

Tip

Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.

Lorem ipsum dolor sit amet, consectetur adipiscing elit.
Sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris.
Duis aute irure dolor in reprehenderit in voluptate velit esse cillum.

IB Chemistry S2.2.15 Sigma and Pi Bonds Notes

Sigma (σ) and Pi (π) Bonds: Formation and Identification

How Sigma Bonds Form

Characteristics of Sigma Bonds

anim nostrud sit dolore minim proident quis fugiat velit et eiusmod nulla quis nulla mollit dolor sunt culpa aliqua

Duis aute irure dolor in reprehenderit

Excepteur sint occaecat cupidatat non proident

Unlock the rest of this chapter with a free account

Sigma (σ) and Pi (π) Bonds: Formation and Identification

How Sigma Bonds Form

Characteristics of Sigma Bonds

anim nostrud sit dolore minim proident quis fugiat velit et eiusmod nulla quis nulla mollit dolor sunt culpa aliqua

Duis aute irure dolor in reprehenderit

Excepteur sint occaecat cupidatat non proident

Unlock the rest of this chapter with a free account

Structure 1. Models of the particulate nature of matter5 subtopics

Structure 2. Models of bonding and structure4 subtopics

Structure 3. Classification of matter2 subtopics

Reactivity 1. What drives chemical reactions?4 subtopics

Reactivity 2. How much, how fast and how far?3 subtopics

Reactivity 3. What are the mechanisms of chemical change?4 subtopics

IB Chemistry S2.2.15 Sigma and Pi Bonds Notes

Structure 1. Models of the particulate nature of matter5 subtopics

Structure 2. Models of bonding and structure4 subtopics

Structure 3. Classification of matter2 subtopics

Reactivity 1. What drives chemical reactions?4 subtopics

Reactivity 2. How much, how fast and how far?3 subtopics

Reactivity 3. What are the mechanisms of chemical change?4 subtopics

Sigma (σ) and Pi (π) Bonds: Formation and Identification

How Sigma Bonds Form

Characteristics of Sigma Bonds

anim nostrud sit dolore minim proident quis fugiat velit et eiusmod nulla quis nulla mollit dolor sunt culpa aliqua

Duis aute irure dolor in reprehenderit

Excepteur sint occaecat cupidatat non proident

Unlock the rest of this chapter with a free account

Sigma (σ) and Pi (π) Bonds: Formation and Identification

How Sigma Bonds Form

Characteristics of Sigma Bonds

anim nostrud sit dolore minim proident quis fugiat velit et eiusmod nulla quis nulla mollit dolor sunt culpa aliqua

Duis aute irure dolor in reprehenderit

Excepteur sint occaecat cupidatat non proident

Unlock the rest of this chapter with a free account