Module 4: Molecular structure and bonding

Question 1

Exceptions to octet rule

Answer 1

Incomplete octet(BF3)
Unpaired e- radicals(NO)
Hypervalence or Expanded Octets(PCl5 for any atom n = 3 or greater)

Question 2

VBT

Answer 2

A mathematical model which describes the overlap of atomic orbitals.

Question 3

Sigma bond

Answer 3

Bond involves the overlap of two atomic orbital along the internuclear axis. Overlap occurs in an end to end bonding to create a singular phase Molecular orbital.

Question 4

Pi bond

Answer 4

Bond that involves the orbital overlap of 2 phases in 2 atomic orbitals. Bonds exist above and below the internuclear axis.

Question 5

describe the overlap of atomic or hybrid orbitals involved in the formation of σ- and π-bonds, and explain the
relative bond strengths resulting from these interactions in terms of the geometry and extent of orbital overlap

Answer 5

Sigma bonds -