Problem 1
Draw diagrams showing Lewis structures for \(\mathrm{CO}_{2}\) \(\left[\mathrm{NO}_{2}\right]^{+},\left[\mathrm{N}_{3}\right]^{-}\) and \(\mathrm{N}_{2} \mathrm{O}\).
Problem 2
Using VSEPR theory, predict the shape of \(\left[\mathrm{I}_{3}\right]^{-}\) Following from this answer and using isoelectronic relationships, suggest the shapes of \(\left[\mathrm{IBr}_{2}\right]^{-}\) and \(\left[\mathrm{ClF}_{2}\right]^{-}\).
Problem 4
Use VSEPR theory to suggest structures for (a) \(\mathrm{BCl}_{3}\) (b) \(\mathrm{NF}_{3},(\mathrm{c}) \mathrm{SCl}_{2}\) (d) \(\left[\mathrm{I}_{3}\right]^{+},\) (e) \(\mathrm{PCl}_{5},\) (f) \(\left[\mathrm{AsF}_{6}\right]^{-},(\mathrm{g})\left[\mathrm{AlH}_{4}\right]^{-}\) and (h) \(\mathrm{XeF}_{4}\).
Problem 9
How many stereoisomers are possible for each of the following (not all species possess isomers)? (a) Square planar \(\left[\mathrm{PdCl}_{2}\left(\mathrm{PPh}_{3}\right)_{2}\right] ;\) (b) octahedral \(\mathrm{WCl}_{3} \mathrm{F}_{3}\) (c) octahedral \(\mathrm{WCl}_{2} \mathrm{F}_{4} ;\) (d) \(\mathrm{CCl}_{3} \mathrm{H}\) (e) octahedral \(\left[\mathrm{Cr}\left(\mathrm{H}_{2} \mathrm{O}\right)_{5} \mathrm{Cl}\right]^{2+} ;(\mathrm{f}) \mathrm{BBrCl}_{2}\) \((\mathrm{g})\) trigonal bipyramidal \(\mathrm{PCl}_{3} \mathrm{F}_{2} ;\) (h) trigonal bipyramidal \(\mathrm{PClF}_{4}\). Draw structures of the isomers and give them distinguishing labels where appropriate.
Problem 10
Which of the following molecules contain double bonds? (a) \(\mathrm{H}_{2} \mathrm{O}_{2} ;\) (b) \(\mathrm{N}_{2} \mathrm{F}_{2} ;\) (c) \(\mathrm{N}_{2} \mathrm{F}_{4} ;\) (d) \(\mathrm{C}_{2} \mathrm{H}_{4} ;\) (e) \(\mathrm{C}_{2} \mathrm{H}_{2} \mathrm{Cl}_{2} ;(\mathrm{f}) \mathrm{COCl}_{2}\).
Problem 15
The dipole moment of \((Z)-\mathrm{N}_{2} \mathrm{F}_{2}\) in the gas phase is \(0.16 \mathrm{D},\) but \((E)-\mathrm{N}_{2} \mathrm{F}_{2}\) is non-polar. Explain how this difference arises.
Problem 16
(a) How many different fluorine environments are there in \(\mathrm{PF}_{5}\) and \(\mathrm{SF}_{4}\) ? By what names are the sites differentiated? (b) At \(298 \mathrm{K}, \mathrm{NMR}\) spectroscopic investigations of \(\mathrm{PF}_{5}\) and \(\mathrm{SF}_{4}\) indicate that each possesses only one \(\mathrm{F}\) environment. Rationalize these data.
Problem 17
Describe the Berry pseudo-rotation process using \(\mathrm{Fe}(\mathrm{CO})_{5}\) as an example. During the process, are any bonds broken?
Problem 19
Comment on each of the following observations. (a) \(\left[\mathrm{IF}_{5}\right]^{2-}\) and \(\left[\mathrm{XeF}_{5}\right]^{-}\) are pentagonal planar. (b) \(\left[\mathrm{PCl}_{4}\right]\left[\mathrm{PCl}_{3} \mathrm{F}_{3}\right]\) contains tetrahedral and octahedral \(P\) centres, and the anion possesses isomers. (c) Members of the series of complexes \(\left[\mathrm{PtCl}_{4}\right]^{2-}\) \(\left[\mathrm{PtCl}_{3}\left(\mathrm{PMe}_{3}\right)\right]^{-},\left[\mathrm{PtCl}_{2}\left(\mathrm{PMe}_{3}\right)_{2}\right]\) \(\left[\mathrm{PtCl}\left(\mathrm{PMe}_{3}\right)_{3}\right]^{+}\) do not possess the same number of isomers.
