Problem 1
Draw Lewis structures to describe the bonding in the following molecules: (a) \(\mathrm{F}_{2} ;(\mathrm{b}) \mathrm{BF}_{3} ;(\mathrm{c}) \mathrm{NH}_{3} ;(\mathrm{d}) \mathrm{H}_{2} \mathrm{Se}\) (c) \(\mathrm{H}_{2} \mathrm{O}_{2} ;(\mathrm{f}) \mathrm{BeCl}_{2} ;(\mathrm{g}) \mathrm{SiH}_{4} ;(\mathrm{h}) \mathrm{PF}_{5}\)
Problem 2
Use the Lewis structure model to deduce the type of nitrogen-nitrogen bond present in (a) \(\mathrm{N}_{2} \mathrm{H}_{4},\) (b) \(\mathrm{N}_{2} \mathrm{F}_{4}\) (c) \(\mathrm{N}_{2} \mathrm{F}_{2}\) and (d) \(\left[\mathrm{N}_{2} \mathrm{H}_{5}\right]^{+}\)
Problem 3
Draw the resonance structures for the \(\mathrm{O}_{3}\) molecule. What can you conclude about the net bonding picture?
Problem 4
Draw Lewis structures for (a) \(\mathrm{CO}_{2},(\mathrm{b}) \mathrm{SO}_{2},(\mathrm{c}) \mathrm{OF}_{2}\) and (d) \(\mathrm{H}_{2} \mathrm{CO}\)
Problem 5
Each of the following is a radical. For which does a Lewis structure correctly confirm this property: (a) \(\mathrm{NO}\) (b) \(\mathrm{O}_{2}\) (c) \(\mathrm{NF}_{2} ?\)
Problem 7
Using VB theory and the Lewis structure model, determine the bond order in (a) \(\mathrm{H}_{2},(\mathrm{b}) \mathrm{Na}_{2},(\mathrm{c}) \mathrm{S}_{2},(\mathrm{d}) \mathrm{N}_{2}\) and (e) \(\mathrm{Cl}_{2}\) Is there any ambiguity with finding the bond orders by this method?
Problem 8
Does VB theory indicate that the diatomic molecule He \(_{2}\) is a viable species? Rationalize your answer.
Problem 9
(a) Use MO theory to determine the bond order in each of \(\left[\mathrm{He}_{2}\right]^{+}\) and \(\left[\mathrm{He}_{2}\right]^{2+}\) (b) Does the MO picture of the bonding in these ions suggest that they are viable species?
Problem 10
(a) Construct an MO diagram for the formation of \(\mathrm{O}_{2}\) show only the participation of the valence orbitals of the oxygen atoms. (b) Use the diagram to rationalize the following trend in \(\mathrm{O}-\mathrm{O}\) bond distances: \(\mathrm{O}_{2}, 121 \mathrm{pm}\) \(\left[\mathrm{O}_{2}\right]^{+}, 112 \mathrm{pm} ;\left[\mathrm{O}_{2}\right]^{-}, 134 \mathrm{pm} ;\left[\mathrm{O}_{2}\right]^{2-}, 149 \mathrm{pm} .\) (c) Which of these species are paramagnetic?
Problem 11
Confirm that the octet rule is obeyed by each of the atoms in the following molecules: (a) \(\mathrm{CF}_{4},\) (b) \(\mathrm{O}_{2}\) , (c) AsBr \(_{3}\) (d) \(\mathrm{SF}_{2}\)
