The [Cr(H₂O)₆]³⁺ ion is violet, and [Cr(CN)₆]^3- is yellow. Explain this difference using crystal field theory. Use the colors to order H₂O and CN^- in the spectrochemical series.

Draw all possible diastereoisomers of [Cr(C₂O₄)₂(H₂O)₂]^-. Which can exist as a pair of enantiomers?

What is the name of the compound [Fe(H2O)5(SCN)]Cl2? 

(a) pentaaquathiocyanatoiron(III) chloride 

(b) pentaaquachlorothiocyanato iron(III) 

(c) pentaaquathiocyanatoiron(III) dichloride

(d) pentaaquathiocyanatoiron(II) chloride

What hybrid orbitals are used by the metal ion and how many unpaired electrons are present the complex ion [VCl₄]^- with tetrahedral geometry?

(a) sp³; 2 unpaired electrons

(b) sp³; 3 unpaired electrons

(c) sp³d²; 3 unpaired electrons

(d) sp³d²; 4 unpaired electrons

What is the oxidation state of the metal in each of the complexes?

a. AgCl₂^–

b. [Cr(H2O)₅Cl]²⁺

c. [Co(NCS)₄]^2–

d. [ZrF₈]^4–

e. [Fe(EDTA)(H₂O)]^–

Based on effective nuclear charge (Z_eff), which ion is the strongest oxidizing agent? 

(a) Cu²⁺

(b) Ni²⁺

(c) Fe²⁺

(d) Mn²⁺

Tell how many diastereoisomers are possible for each of the following complexes, and draw their structures. 

(a) Pt(NH₃)₃Cl (square planar) 

(b) [FeBr₂Cl₂(en)]^-

Two first-series transition metals have three unpaired electrons in complex ions of the type [MCl4]2-.

(a) What are the oxidation state and the identity of M in these complexes?

(b) Draw valence bond orbital diagrams for the two possible ions.

(c) Based on common oxidation states of first-series transition metals (Figure 21.6), which ion is more likely to exist?

<QUESTION REFERENCES FIGURE 21.6>

What is the systematic name for each of the following ions?

(a) [MnCl₄]^2-

(b) [Ni(NH₃)₆]²⁺

Cobalt(III) trifluoroacetylacetonate, Co(tfac)₃, is a sixc oordinate, octahedral metal chelate in which three planar, bidentate tfac ligands are attached to a central Co atom:

(a) Draw all possible diastereoisomers and enantiomers of Co(tfac)₃.

For each of the following complexes, describe the bonding using valence bond theory. Include orbital diagrams for the free metal ion and the metal ion in the complex. Indicate which hybrid orbitals the metal ion uses for bonding, and specify the number of unpaired electrons. 

(a) [AuCl4]2 (square planar)

Six isomers for a square planar palladium(II) complex that contains two Cl-and two SCN-ligands are shown below.

(a) Which structures are cis-trans isomers?

(b) Which structures are linkage isomers?

What is the systematic name for each of the following coordination compounds? 

(a) Cs[FeCl₄]

(b) [V(H₂O)₆](NO₃)₃

Constitutional isomers of a ruthenium(II) coordination compound are shown below.

(a) Give the formula and name for structures 1-3.

(b) Which structures are linkage isomers? 

(c) Which structures are ionization isomers?

Assign a systematic name to each of the following ions.  

(a) [AuCl₄]^-

(b) [Fe(CN)₆]^4-

Draw a crystal field energy-level diagram, and predict the number of unpaired electrons for each of the following: 

(a) [Mn(H2O)6]2+

Nickel(II) complexes with the formula NiX₂L₂, where X⁻ is Cl⁻ or N-bonded NCS⁻ and L is the monodentate triphenylphosphine ligand P(C₆H₅)₃, can be square planar or tetrahedral.

(a) Draw crystal field energy-level diagrams for a square planar and a tetrahedral nickel(II) complex, and show the population of the orbitals.

Cobalt(III) trifluoroacetylacetonate, Co(tfac)₃, is a sixcoordinate, octahedral metal chelate in which three planar, bidentate tfac ligands are attached to a central Co atom:

(b) Diastereoisomers A and B have dipole moments of 6.5 D and 3.8 D, respectively. Which of your diastereoisomers is A and which is B?

Tell how many diastereoisomers are possible for each of the following complexes, and draw their structures. 

(c) [Cu(H₂O)₄Cl₂]⁺

(d) Ru(NH₃)₃I₃

For each of the following complexes, draw a crystal field energy-level diagram, assign the electrons to orbitals, and predict the number of unpaired electrons.

(b) [MnCl4]2- (tetrahedral)

Give a valence bond description of the bonding in each of the following complexes. Include orbital diagrams for the free metal ion and the metal ion in the complex. Indicate which hybrid orbitals the metal ion uses for bonding, and specify the number of unpaired electrons. 

(b) [NiBr₄]^2- (tetrahedral) 

Predict the number of unpaired electrons for each of the following.

(c) Mn3+

(d) Cr2+

For each of the following complexes, describe the bonding using valence bond theory. Include orbital diagrams for the free metal ion and the metal ion in the complex. Indicate which hybrid orbitals the metal ion uses for bonding, and specify the number of unpaired electrons. 

(b) [Ag(NH3)2]+

What is the systematic name for each of the following ions? 

(c) [Co(CO₃)₃]^3-

(d) [Pt(en)₂(SCN)₂]²⁺

Assign a systematic name to each of the following ions.

(c) [Fe(H₂O)₅NCS]²⁺

(d) [Cr(NH₃)₂(C₂O₄)₂]^-

For each of the following complexes, draw a crystal field energy-level diagram, assign the electrons to orbitals, and predict the number of unpaired electrons.

(c) [Co(NCS)4]2- (tetrahedral)

Spinach contains a lot of iron but is not a good source of dietary iron because nearly all the iron is tied up in the oxalate complex [Fe(C₂O₄)₃]^3-.

(c) Draw a crystal field energy-level diagram for [Fe(C₂O₄)₃]^3-, and predict the number of unpaired electrons. (C₂O₄^2- is a weak-field bidentate ligand.)

The percent iron in iron ore can be determined by dissolving the ore in acid, then reducing the iron to Fe2+, and finally titrating the Fe2+ with aqueous KMnO4. The reaction products are Fe2+ and Mn2+.

(c) Draw a crystal field energy-level diagram for the reactants and products, MnO4-, 3Fe1H2O2642+, 3Fe1H2O2643+, and 3Mn1H2O2642+, and predict the number of unpaired electrons for each.

Nickel(II) complexes with the formula NiX₂L₂, where X is Cl^- or N-bonded NCS^- and L is the monodentate triphenylphosphine ligand P(C₆H₅)₃, can be square planar or tetrahedral.

(c) Draw possible structures for each of the NiX₂L₂ complexes, and tell which ones have a dipole moment.

In acidic aqueous solution, the complex trans-[Co(en)₂Cl₁]²⁺(aq) undergoes the following substitution reaction:

trans-[Co(en)₁Cl₂]⁺(aq) + H₂O(l) → trans-[Co(en)₂(H₂O)Cl]²⁺(aq) + Cl^–(aq)

The reaction is first order in trans-[Co(en)₂Cl₂]⁺(aq), and the rate constant at 25°C is 3.2×10^–5 s^–1.

(d) Is the reaction product chiral or achiral? Explain.