The stabilization energy of a bond or interatomic interaction is the change in energy upon breakage of a bond between two atoms (i.e., the change in energy when the atoms are moved away from each other). We can classify bonds into the following categories, based on their dissociation energies:
Strong: > 300 kJ mol-1
Medium: 20-200 kJ mol-1
Weak: 5-20 kJ mol-1
Very weak: 0-5 kJ mol-1
Consider the bonds highlighted in gray in the diagram below.
a. First consider the bonds in molecules isolated from all other molecules (in a vacuum). Classify each of them into the four categories given above, based on your estimation of the bond strength.
b. Which of these bonds could be broken readily by thermal fluctuations?
c. Next, consider what happens when these molecules are immersed in water (fully solvated). For each bond, indicate whether it becomes weaker, stronger, or stays the same in water.
d. Which of these bonds could be broken readily by thermal fluctuations in water?