Expanded Octets and Molecular Geometry

The video tutorial explains the concept of an expanded octet, where the central atom in a Lewis structure has more than eight electrons, defying the octet rule. It is possible with nonmetals having an atomic number of 15 or greater, such as sulfur, phosphorus, and iodine. These molecules, often called hypervalent, can form trigonal bipyramidal and octahedral geometries. The tutorial provides examples of sulfur hexafluoride and the triiodide ion, illustrating how these structures exceed the octet rule and their resulting geometries.

What is an expanded octet?

• A Lewis structure where the central atom has more than eight electrons

• A structure with exactly eight electrons around the central atom

• A structure with no lone pairs

• A molecule with only single bonds

Which of the following elements can form expanded octets?

• Nitrogen

• Sulfur

• Oxygen

• Carbon

What does the term 'hypervalent' refer to?

• Atoms with exactly eight electrons

• Atoms with more than eight electrons

• Atoms with fewer than eight electrons

• Atoms with no electrons

What type of electron geometry is associated with expanded octets?

• Trigonal bipyramidal

• Linear

• Trigonal planar

• Tetrahedral

Which orbitals are involved in the hybridization of expanded octets?

• s and p

• p and d

• s and d

• s, p, and d

How many valence electrons does sulfur hexafluoride have?

• 32

• 12

• 48

• 24

In sulfur hexafluoride, how many electron pairs are around the central sulfur atom?

• Six

• Seven

• Five

• Four

How many valence electrons are present in the triiodide ion?

• 26

• 24

• 22

• 20

What is the molecular geometry of the triiodide ion?

• Trigonal planar

• Octahedral

• Tetrahedral

• Linear

How many lone pairs are placed on the central iodine atom in the triiodide ion?

• Four

• Three

• Two

• One