What is the Lewis base in the reaction of oxalate with the mangenese ion to form [Mn(C2O4)3]2-? What is the oxidation state of Mn and the coordination number of the complex?  

(a) Lewis base is C2O42-; Mn oxidation number is +3; coordination number is 3.

(b) Lewis base is C2O42-; Mn oxidination number is +2; coordination number is 6.

(c) Lewis base is Mn2+; Mn oxidation number is +2; coordination number is 3.

(d) Lewis base is Mn4+; Mn oxidation number is +4; coordination number is 6.

Refer to the figure showing the structure of various ligands to answer questions 4 and 5. Which ligand(s) can participate in linkage isomerism?

(a) All of the ligands can participate in linkage isomerism

(b) I, II, and III

(c) I and IV

(d) II and IV

Identify the false statement about the structures of the complex ion [Fe(en)2Cl2]+ shown below.

(a) Structures I and II are cis-trans isomers.

(b) Structures I and IV are cis-trans isomers.

(c) Structures I and III are enantiomers.

(d) Structures II and IV are enantiomers.

Propose structures for molecules that meet the following

descriptions.

(c) Contains an S atom that has a coordinate covalent bond

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 electron configuration of Co²⁺ and how many unpaired electrons are in the free transition metal ion?

(a) [Ar]3d⁵4s²; 5 unpaired electrons

(b) [Ar]3d⁵4s²; 1 unpaired electron

(c) [Ar]3d⁷; 3 unpaired electrons

(d) [Ar]3d⁷; 1 unpaired electron

Draw a crystal field energy-level diagram for the 3d orbitals of titanium in [Ti(H₂O)₆]³⁺]. Indicate the crystal field splitting, and explain why is [Ti(H₂O)₆]³⁺] colored.

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.

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. 

(a) [CrF₆]^3-

(b) [V(H₂O)₆]³⁺

(c) [Fe(CN)₆]^3-

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

(a) [Cu(en)₃]²⁺

(b) [FeF₆]^2-

(c) [Co(en)₃]³⁺ (low spin) 

The Ni²⁺(aq) cation is green, but Zn²⁺(aq) is colorless. Explain.

Draw a crystal field energy-level diagram for a square planar complex, and explain why square planar geometry is especially common for d⁸ complexes.

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. 

(d) [Cu(en)2]2+ (square planar) 

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.

(a) [Pt(NH3)4]2+ (square planar)

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)

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)

Which of the following complexes are paramagnetic?

(a) [Mn(CN)₆]^3-

(b) [Zn(NH₃)₄]²⁺ (tetrahedral)

(c) [Fe(CN)₆]^4-

(d) [FeF₆]^4-

Which of the following complexes are diamagnetic?

(a) [Ni(H₂O)₆]²⁺

(b) [Co(CN)₆]^3-

(c) [HgI₄]^2- (tetrahedral) 

(d) [Cu(NH₃)₄]²⁺ (square planar) 

Although Cl^- is a weak-field ligand and CN^- is a strong field ligand, [CrCl₆]^3- and [Cr(CN)₆]^3- exhibit approximately the same amount of paramagnetism. Explain.

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

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

Explain why [CoCl₄]^2- (blue) and [Co(H₂O)₆]²⁺ (pink) have different colors. Which complex has its absorption bands at longer wavelengths?

Look at the colors of the isomeric complexes in Figure 21.12, and predict which is the stronger field ligand, nitro (-NO₂) of nitrito (-ONO). Explain. 

Predict the crystal field energy-level diagram for a linear ML2 complex that has two ligands along the :

Predict the crystal field energy-level diagram for a square pyramidal ML₅ complex that has two ligands along the axes but only one ligand along the z axis. Your diagram should be intermediate between those for an octahedral ML₆ complex and a square planar ML₄ complex.

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) 

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)

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]+

There are two possible [M(OH)4]- complexes of first-series transition metals that have three unpaired electrons.

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

(b) Using orbital diagrams, give a valence bond description of the bonding in each complex.

(c) Based on common oxidation states of first-series transition metals (Figure 21.6), which [M(OH)4]- complex is more likely to exist? 

<QUESTION REFERENCES FIGURE 21.6>-

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>