Expanded Octets and Sulfur Compounds

The video discusses the concept of expanded octets, which occur when atoms have more than eight electrons. These are found in elements from Period 3 and higher due to accessible D orbitals. Examples include phosphorus pentachloride and sulfur hexachloride. The video also explores the dilemma of octet expansion in sulfuric acid, where two possible structures are considered. Experiments show that the structure with expanded octets and zero formal charges is preferred due to shorter sulfur-oxygen bond lengths.

What is an expanded octet?

• An atom with exactly eight electrons

• An atom with less than eight electrons

• An atom with more than eight electrons

• An atom with no electrons

In which period do elements start showing expanded octets?

• Period 1

• Period 2

• Period 3

• Period 4

Why are D orbitals considered energetically accessible?

• They are higher in energy than S orbitals

• They are not much higher in energy than P orbitals

• They are at the same energy level as P orbitals

• They are lower in energy than P orbitals

Which compound has a phosphorus atom with an expanded octet?

• Phosphorus pentachloride

• Water

• Sulfur hexachloride

• Sulfuric acid

How many electrons are in the expanded octet of sulfur in sulfur hexachloride?

• 14

• 12

• 10

• 8

What is the main issue when drawing the Lewis structure for sulfuric acid?

• Deciding whether to expand the octet of sulfur

• Choosing the correct number of hydrogen atoms

• Determining the number of oxygen atoms

• Finding the correct bond angles

What formal charge does sulfur have in the non-expanded octet structure of sulfuric acid?

• 0

• -1

• +2

• +1

What do experiments suggest about the sulfur-oxygen bonds in sulfuric acid?

• They resemble sulfur-oxygen double bonds

• They are weaker than expected

• They resemble sulfur-oxygen single bonds

• They are longer than expected

Which structure is preferred for sulfuric acid based on experimental evidence?

• The structure with non-expanded octet and formal charges

• The structure with expanded octet and formal charges

• The structure with non-expanded octet and zero formal charges

• The structure with expanded octet and zero formal charges

What is the main benefit of expanding the octet in sulfuric acid?

• Increased bond length

• Reduced formal charges

• Increased number of hydrogen atoms

• Decreased bond strength