Transition Metals and Coordination Chemistry

Predict the products of each of the following reactions. (Note: In addition to using the information in this chapter, also use the knowledge you have accumulated at this stage of your study, including information on the prediction of reaction products.)

\(\begin{aligned}(a)Fe(s) + {H_2}S{O_4}(aq) \to \\(b)FeC{l_3}(aq) + NaOH(aq) \to \\(c)Mn{(OH)_2}(s) + HBr(aq) \to \\(d)Cr(s) + {O_2}(g) \to \\(e)M{n_2}{O_3}(s) + HCl(aq) \to \\(f)Ti(s) + xs{F_2}(g) \to \end{aligned}\)

Draw diagrams for any cis, trans, and optical isomers that could exist for the following (en is ethylenediamine):

\(\begin{aligned}{\underline{\phantom{xx}}}(a){\left( {Co{{(en)}_2}\left( {N{O_2}} \right)Cl} \right)^ + }\\(b){\left( {Co{{(en)}_2}C{l_2}} \right)^ + }\\(c)\left( {Pt{{\left( {N{H_3}} \right)}_2}C{l_4}} \right)\\(d){\left( {Cr{{(en)}_3}} \right)^{3 + }}\\(e)\left( {Pt{{\left( {N{H_3}} \right)}_2}C{l_2}} \right)\end{aligned}\)

Which of the following is the strongest oxidizing agent: \(VO_4^3,CrO_4^{2 - },\)or \(MnO_4^ - \)?

Which of the following elements is most likely to form an oxide with the formula\(M{O_3}\) : Zr, Nb, or Mo?

The following reactions all occur in a blast furnace. Which of these are redox reactions?

\(\begin{aligned}{l}(a)3F{e_2}{O_3}(s) + CO(g) \to 2F{e_3}{O_4}(s) + C{O_2}(g)\\(b)F{e_3}{O_4}(s) + CO(g) \to 3FeO(s) + C{O_2}(g)\\(c)FeO(s) + CO(g) \to Fe(l) + C{O_2}(g)\\(d)C(s) + {O_2}(g) \to C{O_2}(g)\\(e)C(s) + C{O_2}(g) \to 2CO(g)\\(f)CaC{O_3}(s) + CaO(s) \to C{O_2}(g)\\(g)CaO(s) + Si{O_2}(s) \to CaSi{O_3}(l)\end{aligned}\)

Why is the formation of slag useful during the smelting of iron?

Would you expect an aqueous manganese (VII) oxide solution to have a pH greater or less than 7.0? Justify your answer.

How many cubic feet of air at a pressure of 760 torr and 0 °C is required per ton of \(F{e_2}{O_3}\)to convert that \(F{e_2}{O_3}\)into iron in a blast furnace? For this exercise, assume air is 19% oxygen by volume.

A 2.5624-g sample of a pure solid alkali metal chloride is dissolved in water and treated with excess silver nitrate. The resulting precipitate, filtered and dried, weighs 3.03707 g. What was the percent by mass of chloride ion in the original compound? What is the identity of the salt?

The standard reduction potential for the reaction \({(Co{({H_2}O)_6})^{3 + }}(aq) + {e^ - } \to {(Co{({H_2}O)_6})^{2 + }}(aq)\)is about 1.8 V. The reduction potential for the reaction \({(Co{(N{H_3})_6})^{3 + }}(aq) + {e^ - } \to {(Co{(N{H_3})_6})^{2 + }}(aq)\) is +0.1 V. Calculate the cell potentials to show whether the complex ions, \({(Co{({H_2}O)_6})^{2 + }}\) and/or\({(Co{(N{H_3})_6})^{2 + }}\), can be oxidized to the corresponding cobalt (III) complex by oxygen.

Describe the electrolytic process for refining copper.

Predict the products of each of the following reactions and then balance the chemical equations.

(a) Fe is heated in an atmosphere of steam.

(b) NaOH is added to a solution of Fe(NO₃)₃.

(c) FeSO₄ is added to an acidic solution of KMnO₄.

(d) Fe is added to a dilute solution of H₂SO₄.

(e) A solution of Fe(NO₃)₂ and HNO₃ is allowed to stand in air.

(f) FeCO₃ is added to a solution of HClO₄.

(g) Fe is heated in air.

Give the oxidation state of the metal for each of the following oxides of the first transition series. (Hint: Oxides of formula M₃O₄  are examples of mixed valence compounds in which the metal ion is present in more than one oxidation state. It is possible to write these compound formulas in the equivalent format MO∙M₂O₃, to permitestimation of the metal’s two oxidation states.)

(a) Sc₂O₃

(b) TiO₂

(c) V₂O₅

(d) CrO₃

(e) MnO₂

(f) Fe₃O₄

(g) Co₃O₄

(h) NiO

(i) Cu₂O

Indicate the coordination number for the central metal atom in each of the following coordination compounds:

\(\begin{aligned}{\underline{\phantom{xx}}}(a)\left( {Pt{{\left( {{H_2}O} \right)}_2}B{r_2}} \right)\\(b)\left( {Pt\left( {N{H_3}} \right)(py)(Cl)(Br)} \right)\left( {py = } \right.pyridine,\left. {{C_5}{H_5}\;N} \right)\\(c)\left( {Zn{{\left( {N{H_3}} \right)}_2}C{l_2}} \right)\\(d)\left( {Zn\left( {N{H_3}} \right)(py)(Cl)(Br)} \right)\\(e)\left( {Ni{{\left( {{H_2}O} \right)}_4}C{l_2}} \right)\\(f){\left( {Fe{{(en)}_2}{{(CN)}_2}} \right)^ + }\left( {en = } \right.ethylenediamine,\left. {{C_2}{H_8}\;{N_2}} \right)\end{aligned}\)

Give the coordination numbers and write the formulas for each of the following, including all isomers where appropriate: 

  (a) tetrahydroxozincate(II) ion (tetrahedral) 

  (b) hexacyanopalladate(IV) ion 

  (c) dichloroaurate(I) ion (note that aurum is Latin for “gold”) 

  (d) diamminedichloroplatinum(II) 

  (e) potassium diamminetetrachlorochromate(III) 

  (f) hexaamminecobalt(III) hexacyanochromate(III) 

  (g) dibromobis(ethylenediamine) cobalt(III) nitrate

Give the coordination number for each metal ion in the following compounds:

\(\begin{aligned}{\underline{\phantom{xx}}}(a){\left( {Co{{\left( {C{O_3}} \right)}_3}} \right)^{3 - }}\\(b){\left( {Cu{{\left( {N{H_3}} \right)}_4}} \right)^{2 + }}\\(c){\left( {Co{{\left( {N{H_3}} \right)}_4}B{r_2}} \right)_2}{\left( {S{O_4}} \right)_3}\\(d)\left( {Pt{{\left( {N{H_3}} \right)}_4}} \right)\left( {PtC{l_4}} \right)\\(e)\left( {Cr{{(en)}_3}} \right){\left( {N{O_3}} \right)_3}\\(f)\left( {Pd{{\left( {N{H_3}} \right)}_2}B{r_2}} \right)\\(g){K_3}\left( {Cu{{(Cl)}_5}} \right)\\(h)\left( {Zn{{\left( {N{H_3}} \right)}_2}C{l_2}} \right)\end{aligned}\)

Sketch the structures of the following complexes. Indicate any cis, trans, and optical isomers.

\(\begin{aligned}{\underline{\phantom{xx}}}(a)\left( {Pt{{\left( {{H_2}O} \right)}_2}B{r_2}} \right)\\(b)\left( {Pt\left( {N{H_3}} \right)(py)(Cl)(Br)} \right)\\(c)\left( {Zn{{\left( {N{H_3}} \right)}_3}Cl} \right)\\(d){\left( {Pt{{\left( {N{H_3}} \right)}_3}Cl} \right)^ + }\\(e)\left( {Ni{{\left( {{H_2}O} \right)}_4}C{l_2}} \right)\\(f){\left( {Co{{\left( {{C_2}{O_4}} \right)}_2}C{l_2}} \right)^{3 - }}\end{aligned}\)

Name each of the compounds or ions given in \(Exercise 19.28,\)including the oxidation state of the metal.

Name each of the compounds or ions given in \(Exercise 19.30\).

Specify whether the following complexes have isomers.

\(\begin{aligned}{\underline{\phantom{xx}}}(a)tetrahedral\left( {Ni{{(CO)}_2}{{(Cl)}_2}} \right)\\(b)trigonalbipyramidal\left( {Mn{{(CO)}_4}NO} \right)\\(c)\left( {Pt{{(en)}_2}C{l_2}} \right)C{l_2}\end{aligned}\)

Predict whether the carbonate ligand \(C{O_3}^2\)- will coordinate to a metal center as a monodentate, bidentate, or tridentate ligand.

Draw the geometric, linkage, and ionization isomers for \(\left( {CoC{l_5}CN} \right)(CN)\)

Determine the number of unpaired electrons expected for \({\left( {{\rm{Fe}}{{\left( {{\rm{N}}{{\rm{O}}_2}} \right)}_6}} \right)^{3 - }}\)and for \({\left( {Fe{F_6}} \right)^{3 - }}\)in terms of crystal field theory.

Draw the crystal field diagrams for \({\left( {Fe{{\left( {N{O_2}} \right)}_6}} \right)^{4 - }}\)and \({\left( {Fe{F_6}} \right)^{3 - }}.\)State whether each complex is high spin or low spin, paramagnetic or diamagnetic, and compare \({\Delta _{oct }}\)to \(P\)for each complex.

Give the oxidation state of the metal, number of \(d\)electrons, and the number of unpaired electrons predicted for \(\left( {Co{{\left( {N{H_3}} \right)}_6}} \right)C{l_3}. \)

The solid anhydrous solid \(CoC{l_2}\)is blue in color. Because it readily absorbs water from the air, it is used as a humidity indicator to monitor if equipment (such as a cell phone) has been exposed to excessive levels of moisture. Predict what product is formed by this reaction, and how many unpaired electrons this complex will have.

Is it possible for a complex of a metal in the transition series to have six unpaired electrons? Explain.

How many unpaired electrons are present in each of the following?

\(\begin{aligned}{\underline{\phantom{xx}}}(a){\left( {Co{F_6}} \right)^{3 - }}(highspin)\\(b){\left( {Mn{{(CN)}_6}} \right)^{3 - }}(lowspin)\\(c){\left( {Mn{{(CN)}_6}} \right)^{4 - }}(lowspin)\\(d){\left( {MnC{l_6}} \right)^{4 - }}(highspin)\\(e){\left( {RhC{l_6}} \right)^{3 - }}(lowspin)\end{aligned}\)

Explain how the diphosphate ion,  \({\left( {{O_3}P - O - P{O_3}} \right)^{4 - }}\)  can function as a water softener that prevents the precipitation of \(F{e^{2 + }}\) as an insoluble iron salt.

Trimethylphosphine, \(P{\left( {C{H_3}} \right)_3}\) can act as a ligand by donating the lone pair of electrons on the phosphorus atom. If trimethylphosphine is added to a solution of nickel \(\left( {II} \right)\) chloride in acetone, a blue compound that has a molecular mass of approximately \(270 g\) and contains \(21.5\% Ni,26.0\% Cl,\)and \(52.5\% P{\left( {C{H_3}} \right)_3}\) can be isolated. This blue compound does not have any isomeric forms. What are the geometry and molecular formula of the blue compound?

Would you expect the complex \(\left( {Co{{(en)}_3}} \right)C{l_3}\) to have any unpaired electrons? Any isomers?