A student is investigating the factors that influence covalent bond length and bond energy. The student compiles the following list of four covalent bonds, all of which are single bonds.
• H–F
• H–Cl
• H–Br
• H–I
Atomic (covalent) radii are provided in the data booklet the student is using:
H 37 pm
F 64 pm
Cl 99 pm
Br 114 pm
I 133 pm
Answer the following questions about the set of bonds above.
(a) Rank the four bonds from shortest to longest equilibrium bond length. Clearly indicate any ties if you believe two bonds have essentially the same length.
(b) Rank the same four bonds from largest to smallest average bond energy. Again, clearly indicate any ties if appropriate.
(c) Describe, in terms of atomic size and electrostatic attraction, the reasoning that justifies the trend you proposed in part (a).
(d) Explain how the trend described in part (a) gives rise to the trend in bond energies you reported in part (b). Your explanation should reference potential energy as a function of internuclear distance.