Why does sulfur form expanded valence shell compounds such as SF6, whereas oxygen does not?

Name: Problem 4, Chapter 20: Chemistry Principles and Practice
Uploaded: 2022-01-23T08:36:32-08:00
Duration: 1 min 28 s
Channel: Adriano Chikande
Description: Why does sulfur form expanded valence shell compounds such as SF6, whereas oxygen does not?

step 1 In this question we're going to be comparing sulphur and oxygen. So looking at sulphur it can ex

Why does sulfur form expanded valence shell compounds such...

Key Concepts

Octet Rule

The octet rule is a chemical guideline that states atoms tend to form bonds until they are surrounded by eight electrons. However, this rule has exceptions, particularly for atoms beyond the second period, which can accommodate more than eight electrons in their valence shells.

Expanded Valence Shell

An expanded valence shell refers to the ability of certain atoms, especially those in the third period and below, to hold more than eight electrons. This is possible because they have access to additional orbitals beyond the 2s and 2p, allowing the atom to form more bonds than would be predicted by the octet rule alone.

Availability of d Orbitals

Elements like sulfur (in the third period) have vacant d orbitals that can be used in bonding, permitting the accommodation of extra electron pairs. These d orbitals enable sulfur to form compounds such as SF6 that have more than eight electrons around the central atom, while oxygen, being in the second period, does not have available d orbitals for such expanded bonding.

Atomic Size and Electronegativity

Sulfur’s larger atomic size and lower electronegativity compared to oxygen allow it to better distribute and stabilize additional electron density. This makes sulfur more capable of forming stable hypervalent compounds, whereas the smaller size and higher electronegativity of oxygen restrict its ability to expand its valence shell.

Transcript

Please give Ace some feedback