Problem 1
What is the oxidation state of the central atom (in pink) in each of the following compounds or ions: \((a) S C l_{2} ;(b) P O C l_{3} ;(c)\left[X e F_{5}\right]^{-} ;(d)\left[S b_{2} F_{11}\right]^{-}\) \((\mathrm{c})\left[\mathrm{HPO}_{4}\right]^{2-} ;(\mathrm{f}) \mathrm{Al}_{2} \mathrm{O}_{3} ;(\mathrm{g}) \mathrm{Me}_{2} \operatorname{Sn} \mathrm{F}_{2} ;(\mathrm{h})\) \(\left[\mathrm{Cr}_{2} \mathrm{O}_{7}\right]^{2-} ;(\mathrm{i})\left[\mathrm{MnO}_{4}\right]^{-} ;(\mathrm{j})\left[\mathrm{IO}_{4}\right]^{-},(\mathrm{k})\left[\mathrm{S}_{2}\right]^{2-} ?\)
Problem 5
Use VSEPR theory to predict the structures of (a) \(\left[\ln B r_{6}\right]^{3-}\) (b) \(\left[\mathrm{GaCl}_{5}\right]^{2-}\) and (c) \(\left[\mathrm{GaCl}_{4}\right]^{-}\). In the salt \(\left[\left(C_{2} H_{5}\right)_{4} N\right]_{2}\left[\operatorname{In} C l_{5}\right],\) the dianion has a squarebased pyramidal structure. Suggest possible reasons for this geometry.
Problem 6
By considering the atomic orbitals that are available on carbon and silicon, suggest why two \(\mathrm{C}=\mathrm{O}\) double bonds are energetically preferred to four \(\mathrm{C}-\mathrm{O}\) single bonds, but four \(\mathrm{Si}-\mathrm{O}\) single bonds are energetically preferred to two \(\mathrm{Si}=\mathrm{O}\) double bonds.
Problem 9
Draw the structure of the azide ion. With which oxide of nitrogen is it isoelectronic?
Problem 13
Suggest likely products for the following reactions which are balanced on the left-hand side: \\[ \begin{array}{l} \mathrm{SbF}_{5}+\mathrm{BrF}_{3}-- \\ \mathrm{KF}+\mathrm{AsF}_{5}-= \\ \mathrm{PF}_{5}+2 \mathrm{SbF}_{5}-= \end{array} \\]
Problem 16
Suggest why some \(p\) -block elements occur in the elemental state while others occur only as compounds. Give examples.
Problem 17
Write down possible products from the reaction of (a) \(\mathrm{I}_{2}\) with \(\mathrm{F}_{2}\) and (b) \(\mathrm{Cl}_{2}\) with \(\mathrm{Br}_{2}\), In each case, also give the expected reactions of the products you have written with water.
Problem 18
Suggest why compounds of the noble gases appear to be essentially restricted to xenon. Your arguments might lead you to suggest that radon should form compounds similar to those of xenon why do you think such compounds have not been included in our discussions?
Problem 19
If xenon oxo-compounds are such good oxidizing agents, and only give gaseous xenon as a product, why do you think they are not more commonly used in the laboratory?
Problem 20
What do you understand by the term acid anhydride? What are the anhydrides of (a) \(\mathrm{HNO}_{2}\) (b) \(\mathrm{HNO}_{3}\) (c) \(\mathrm{H}_{3} \mathrm{PO}_{4}\) \((d) H_{3} P O_{3}\) (e) HOCl and \((f) H I O_{3} ?\)
