Problem 39
Use the following reaction to define the terms redox reaction, half-reaction, oxidizing agent, and reducing agent: \(4 \mathrm{Na}(s)+\mathrm{O}_{2}(g) \longrightarrow 2 \mathrm{Na}_{2} \mathrm{O}(s)\)
Problem 40
Is it possible to have a reaction in which oxidation occurs and reduction does not? Explain.
Problem 41
For the complete redox reactions given here, break down each reaction into its half-reactions, identify the oxidizing agent, and identify the reducing agent. (a) \(2 \mathrm{Sr}+\mathrm{O}_{2} \longrightarrow 2 \mathrm{Sr} \mathrm{O}\) (b) \(2 \mathrm{Li}+\mathrm{H}_{2} \longrightarrow 2 \mathrm{LiH}\) (c) \(2 \mathrm{Cs}+\mathrm{Br}_{2} \longrightarrow 2 \mathrm{CsBr}\) (d) \(3 \mathrm{Mg}+\mathrm{N}_{2} \longrightarrow \mathrm{Mg}_{3} \mathrm{~N}_{2}\)
Problem 42
For the complete redox reactions given here, break down each reaction into its half-reactions, identify the oxidizing agent, and identify the reducing agent. (a) \(2 \mathrm{Sr}+\mathrm{O}_{2} \longrightarrow 2 \mathrm{Sr} \mathrm{O}\) (b) \(2 \mathrm{Li}+\mathrm{H}_{2} \longrightarrow 2 \mathrm{LiH}\) (c) \(2 \mathrm{Cs}+\mathrm{Br}_{2} \longrightarrow 2 \mathrm{CsBr}\) (d) \(3 \mathrm{Mg}+\mathrm{N}_{2} \longrightarrow \mathrm{Mg}_{3} \mathrm{~N}_{2}\)
Problem 43
Arrange the following species in order of increasing oxidation number of the sulfur atom: (a) \(\mathrm{H}_{2} \mathrm{~S},(\mathrm{~b}) \mathrm{S}_{8}\) (c) \(\mathrm{H}_{2} \mathrm{SO}_{4}\) (d) \(\mathrm{S}^{2-}\) (e) HS \(^{-}\), (f) \(\mathrm{SO}_{2},(\mathrm{~g}) \mathrm{SO}_{3}\)
Problem 44
Phosphorus forms many oxoacids. Indicate the oxidation number of phosphorus in each of the following acids: (a) \(\mathrm{HPO}_{3},\) (b) \(\mathrm{H}_{3} \mathrm{PO}_{2},\) (c) \(\mathrm{H}_{3} \mathrm{PO}_{3}\), (d) \(\mathrm{H}_{3} \mathrm{PO}_{4},\) (e) \(\mathrm{H}_{4} \mathrm{P}_{2} \mathrm{O}_{7}\) (f) \(\mathrm{H}_{5} \mathrm{P}_{3} \mathrm{O}_{10}\)
Problem 45
Give the oxidation numbers for the underlined atoms in the following molecules and ions: (a) \(\mathrm{ClF},(\mathrm{b}) \mathrm{IF}_{7}\) (c) \(\underline{\mathrm{C}} \mathrm{H}_{4}\) (d) \(\underline{\mathrm{C}}_{2} \mathrm{H}_{2}\) (e) \(\underline{\mathrm{C}}_{2} \mathrm{H}_{4}\) (f) \(\mathrm{K}_{2} \mathrm{Cr} \mathrm{O}_{4},(\mathrm{~g}) \mathrm{K}_{2} \mathrm{Cr}_{2} \mathrm{O}_{7}\) (h) \(\mathrm{KMnO}_{4}\), (i) \(\mathrm{NaHCO}_{3},(\mathrm{j}) \mathrm{Li}_{2},(\mathrm{k}) \mathrm{NaIO}_{3},\) (I) \(\mathrm{KO}_{2}\), \((\mathrm{m}) \mathrm{PF}_{6}^{-},(\mathrm{n}) \mathrm{K} \mathrm{AuCl}_{4}\)
Problem 46
Give the oxidation number for the following species: \(\mathrm{H}_{2}, \mathrm{Se}_{\mathrm{g}}, \mathrm{P}_{4}, \mathrm{O}, \mathrm{U}, \mathrm{As}_{4}, \mathrm{~B}_{12}\)
Problem 47
Give the oxidation numbers for the underlined atoms in the following molecules and ions: (a) \(\underline{\mathrm{Cs}}_{2} \mathrm{O}\) (b) \(\mathrm{Ca} \underline{\mathrm{I}}_{2}\) (c) \(\mathrm{Al}_{2} \mathrm{O}_{3}\) (d) \(\mathrm{H}_{3} \mathrm{~A}_{\mathrm{s} \mathrm{O}_{3}}\) (e) \(\mathrm{TiO}_{2}\) (f) \(\mathrm{MoO}_{4}^{2-},(\mathrm{g}) \mathrm{PtCl}_{4}^{2-}\) (h) \(\underline{\mathrm{Pt}} \mathrm{Cl}_{6}^{2-}\) (i) \(\underline{\mathrm{Sn}} \mathrm{F}_{2},(\mathrm{j}) \underline{\mathrm{ClF}}_{3},(\mathrm{k}) \underline{\mathrm{Sb} \mathrm{F}_{6}^{-}}\)
Problem 48
Give the oxidation numbers for the underlined atoms in the following molecules and ions: (a) \(\mathrm{Mg}_{3} \mathrm{~N}_{2},\) (b) \(\mathrm{Cs} \underline{\mathrm{O}}_{2},\) (c) \(\mathrm{Ca} \underline{\mathrm{C}}_{2}\) (d) \(\mathrm{CO}_{3}^{2-}\), (e) \(\underline{\mathrm{C}}_{2} \mathrm{O}_{4}^{2-}\) (f) \(\mathrm{ZnO}_{2}^{2-},(\mathrm{g}) \mathrm{Na} \underline{\mathrm{B}} \mathrm{H}_{4}\) (h) \(\underline{\mathrm{W}} \mathrm{O}_{4}^{2-}\)
