Chapter 19

(a) Sc: [Ar]4s²3d¹; (b) Ti: [Ar]4s²3d²; (c) Cr: [Ar]4s¹3d⁵; (d) Fe: [Ar]4s²3d⁶; (e) Ru: [Kr]5s²4d⁶

(a) La: [Xe]6s²5d¹, La³⁺: [Xe]; (b) Sm: [Xe]6s²4f⁶, Sm³⁺: [Xe]4f⁵; (c) Lu: [Xe]6s²4f¹⁴5d¹, Lu³⁺: [Xe]4f¹⁴

Al is used because it is the strongest reducing agent and the only option listed that can provide sufficient driving force to convert La(III) into La.

Mo

The CaSiO₃ slag is less dense than the molten iron, so it can easily be separated. Also, the floating slag layer creates a barrier that prevents the molten iron from exposure to O₂, which would oxidize the Fe back to Fe₂O₃.

2.57%

0.167 V

E° = −0.6 V, E° is negative so this reduction is not spontaneous. E° = +1.1 V

(a) $\text{Fe}(s)+2{\text{H}}_3{\text{O}}^{\text{+}}(aq)+{\text{SO}}_4{}^{\mathrm{2-}}(aq)⟶{\text{Fe}}^{\mathrm{2+}}(aq)+{\text{SO}}_4{}^{\mathrm{2-}}(aq)+{\text{H}}_2(g)+2{\text{H}}_2\text{O}(l);$ (b) ${\text{FeCl}}_3(aq)+{\text{3Na}}^{\text{+}}(aq)+{\text{3OH}}^{\text{−}}(aq)⟶\text{Fe}{(\text{OH})}_3(s)+{\text{3Na}}^{\text{+}}(aq)+{\text{3Cl}}^{\text{+}}(aq);$ (c) $\text{Mn}{(\text{OH})}_2(s)+2{\text{H}}_3{\text{O}}^{\text{+}}(aq)+{\text{2Br}}^{\text{−}}(aq)⟶{\text{Mn}}^{\mathrm{2+}}(aq)+{\text{2Br}}^{\text{−}}(aq)+4{\text{H}}_2\text{O}(l);$ (d) $\text{4Cr}(s)+3{\text{O}}_2(g)⟶2{\text{Cr}}_2{\text{O}}_3(s);$ (e) ${\text{Mn}}_2{\text{O}}_3(s)+6{\text{H}}_3{\text{O}}^{\text{+}}(aq)+{\text{6Cl}}^{\text{−}}(aq)⟶2{\text{MnCl}}_3(s)+9{\text{H}}_2\text{O}(l);$ (f) $\text{Ti}(s)+xs{\text{F}}_2(g)⟶{\text{TiF}}_4(g)$

(a)
$\begin{array}{}\\ \\ {\text{Cr}}_2{({\text{SO}}_4)}_3(aq)+\text{2Zn}(s)+{\text{2H}}_3{\text{O}}^{\text{+}}(aq)⟶{\text{2Zn}}^{\mathrm{2+}}(aq)+{\text{H}}_2(g)+{\text{2H}}_2\text{O}(l)+{\text{2Cr}}^{\mathrm{2+}}(aq)+{\text{3SO}}_4{}^{\mathrm{2-}}(aq);\end{array}$ (b) ${\text{4TiCl}}_3(s)+{\text{CrO}}_4{}^{\mathrm{2-}}(aq)+{\text{8H}}^{\text{+}}(aq)⟶{\text{4Ti}}^{\mathrm{4+}}(aq)+\text{Cr}(s)+{\text{4H}}_2\text{O}(l)+{\text{12Cl}}^{\text{−}}(aq);$ (c) In acid solution between pH 2 and pH 6, ${\text{CrO}}_4{}^{\mathrm{2-}}$ forms ${\text{HCrO}}_4{}^{\text{−}},$ which is in equilibrium with dichromate ion. The reaction is ${\text{2HCrO}}_4{}^{\text{−}}(aq)⟶{\text{Cr}}_2{\text{O}}_7{}^{\mathrm{2-}}(aq)+{\text{H}}_2\text{O}(l).$ At other acidic pHs, the reaction is ${\text{3Cr}}^{\mathrm{2+}}(aq)+{\text{CrO}}_4{}^{\mathrm{2-}}(aq)+{\text{8H}}_3{\text{O}}^{\text{+}}(aq)⟶{\text{4Cr}}^{\mathrm{3+}}(aq)+{\text{12H}}_2\text{O}(l);$ (d) ${\text{8CrO}}_3(s)+\text{9Mn}(s)\stackrel{\text{Δ}}{⟶}{\text{4Cr}}_2{\text{O}}_3(s)+{\text{3Mn}}_3{\text{O}}_4(s);$ (e) $\text{CrO}(s)+{\text{2H}}_3{\text{O}}^{\text{+}}(aq)+{\text{2NO}}_3{}^{\text{−}}(aq)⟶{\text{Cr}}^{\mathrm{2+}}(aq)+{\text{2NO}}_3{}^{\text{−}}(aq)+{\text{3H}}_2\text{O}(l);$ (f) ${\text{CrCl}}_3(s)+\text{3NaOH}(aq)⟶\text{Cr}{(\text{OH})}_3(s)+{\text{3Na}}^{\text{+}}(aq)+{\text{3Cl}}^{\text{−}}(aq)$

(a) $\text{3Fe}(s)+{\text{4H}}_2\text{O}(g)⟶{\text{Fe}}_3{\text{O}}_4(s)+{\text{4H}}_2(g);$ (b) $\text{3NaOH}(aq)+\text{Fe}{({\text{NO}}_3)}_3(aq)\stackrel{{\text{H}}_2\text{O}}{\to }\text{Fe}{(\text{OH})}_3(s)+{\text{3Na}}^{\text{+}}(aq)+3{\text{NO}}_3{}^{\text{−}}(aq);$ (c) $\begin{array}{}\\ \\ \\ \text{MnO}{}^{\mathrm{4-}}+5\text{Fe}{\text{2+}}^{}+8\text{H}{\text{+}}^{}⟶\text{Mn}{}^{\text{2+}}+5{\text{Fe}}_3+4{\text{H}}_2\text{O}\end{array};$ (d) $\text{Fe}(s)+{\text{2H}}_3{\text{O}}^{\text{+}}(aq)+{\text{SO}}_4{}^{\mathrm{2-}}(aq)⟶{\text{Fe}}^{\mathrm{2+}}(aq)+{\text{SO}}_4{}^{\mathrm{2-}}(aq)+{\text{H}}_2(g)+{\text{2H}}_2\text{O}(l);$ (e) ${\text{4Fe}}^{\mathrm{2+}}(aq)+{\text{O}}_2(g)+{\text{4HNO}}_3(aq)⟶{\text{4Fe}}^{\mathrm{3+}}(aq)+{\text{2H}}_2\text{O}(l)+{\text{4NO}}_3{}^{\text{−}}(aq);$ (f) ${\text{FeCO}}_3(s)+{\text{2HClO}}_4(aq)⟶\text{Fe}{({\text{ClO}}_4)}_2(aq)+{\text{H}}_2\text{O}(l)+{\text{CO}}_2(g);$ (g) $\text{3Fe}(s)+{\text{2O}}_2(g)\stackrel{\text{Δ}}{⟶}{\text{Fe}}_3{\text{O}}_4(s)$

As CN⁻ is added,
${\text{Ag}}^{\text{+}}(aq)+{\text{CN}}^{\text{−}}(aq)⟶\text{AgCN}(s)$
As more CN⁻ is added,
$\begin{array}{l}{\text{Ag}}^{\text{+}}(aq)+2{\text{CN}}^{\text{−}}(aq)⟶{[\text{Ag}{\text{(CN)}}_2]}^{\text{−}}(aq)\\ \text{AgCN}(s)+{\text{CN}}^{\text{−}}(aq)⟶{[\text{Ag}{\text{(CN)}}_2]}^{\text{−}}(aq)\end{array}$

(a) Sc³⁺; (b) Ti⁴⁺; (c) V⁵⁺; (d) Cr⁶⁺; (e) Mn⁴⁺; (f) Fe²⁺ and Fe³⁺; (g) Co²⁺ and Co³⁺; (h) Ni²⁺; (i) Cu⁺

(a) 4, [Zn(OH)₄]²⁻; (b) 6, [Pd(CN)₆]²⁻; (c) 2, [AuCl₂]⁻; (d) 4, [Pt(NH₃)₂Cl₂]; (e) 6, K[Cr(NH₃)₂Cl₄]; (f) 6, [Co(NH₃)₆][Cr(CN)₆]; (g) 6, [Co(en)₂Br₂]NO₃

(a) [Pt(H₂O)₂Br₂]:

(b) [Pt(NH₃)(py)(Cl)(Br)]:

(c) [Zn(NH₃)₃Cl]⁺ :

(d) [Pt(NH₃)₃Cl]⁺ :

(e) [Ni(H₂O)₄Cl₂]:

(f) [Co(C₂O₄)₂Cl₂]³⁻:

(a) tricarbonatocobaltate(III) ion; (b) tetraaminecopper(II) ion; (c) tetraaminedibromocobalt(III) sulfate; (d) tetraamineplatinum(II) tetrachloroplatinate(II); (e) tris-(ethylenediamine)chromium(III) nitrate; (f) diaminedibromopalladium(II); (g) potassium pentachlorocuprate(II); (h) diaminedichlorozinc(II)

(a) none; (b) none; (c) The two Cl ligands can be cis or trans. When they are cis, there will also be an optical isomer.

[Co(H₂O)₆]Cl₂ with three unpaired electrons.

(a) 4; (b) 2; (c) 1; (d) 5; (e) 0

(a) [Fe(CN)₆]⁴⁻; (b) [Co(NH₃)₆]³⁺; (c) [Mn(CN)₆]⁴⁻

The complex does not have any unpaired electrons. The complex does not have any geometric isomers, but the mirror image is nonsuperimposable, so it has an optical isomer.

No. Au⁺ has a complete 5d sublevel.