24. Transition Metals and Coordination Compounds

In which compound does Ti exhibit greater metallic behavior:TiF₂ or TiF₆?

Which oxide, CrO₃ or CrO, forms a more acidic aqueous solution?

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

(a) Cu²⁺

(b) Ni²⁺

(c) Fe²⁺

(d) Mn²⁺

What is the general trend in standard potentials for the oxidation of first-series transition metals from Sc to Zn? What is the reason for the trend?

What is the highest oxidation state for each of the elements from Sc to Zn?

What is the general trend in the following properties from left to right across the first-transition series (Sc to Zn)? Explain each trend.

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(a) atomic radius

(b) density

(c) ionization energy

(d) standard oxidation potential

Titanium, used to make jet aircraft engines, is much harder than potassium or calcium. Explain.

Molybdenum (mp 2623 °C) has a higher melting point than yttrium (mp 1522 °C) or cadmium (mp 321 °C). Explain.

Briefly account for each of the following observations:

(a) Atomic radii decrease in the order Sc > Ti > V.

(b) Densities increase in the order Ti > V > Cr.

Arrange the following atoms in order of decreasing atomic radius, and account for the trend.

(a) Cr

(b) Ti

(c) Mn

(d) V

What is the lanthanide contraction, and why does it occur?

The atomic radii of zirconium (160 pm) and hafnium (159 pm) are nearly identical. Explain.

Which of the following transition metals have more than one oxidation state?

(a) Ti

(b) V

(c) Cr

(d) Zn

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>

The highest oxidation state for the early transition metals Sc, Ti, V, Cr, and Mn is the periodic group number. The highest oxidation state for the later transition elements Fe, Co, and Ni is less than the periodic group number. Explain.