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Problem 41
Molybdenum (mp 2623 °C) has a higher melting point than yttrium (mp 1522 °C) or cadmium (mp 321 °C). Explain.
Problem 42
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.
Problem 43
Arrange the following atoms in order of decreasing atomic radius, and account for the trend.
(a) Cr
(b) Ti
(c) Mn
(d) V
Problem 44
What is the lanthanide contraction, and why does it occur?
Problem 45
The atomic radii of zirconium (160 pm) and hafnium (159 pm) are nearly identical. Explain.
- Which element is more easily oxidized, Ti or Zn?
Problem 48
- Which element is more easily oxidized, Sc or Co?
Problem 49
- Write a balanced net ionic equation for the reaction of each of the following metals with dilute sulfuric acid in the absence of air. If no reaction occurs, indicate N.R.: (a) Mn (b) Ag (c) Sc (d) Ni.
Problem 51
Problem 52
Which of the following transition metals have more than one oxidation state?
(a) Ti
(b) V
(c) Cr
(d) Zn
Problem 55
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.
- Which is the stronger oxidizing agent, Cr2+ or Cu2+? Explain.
Problem 56
- Which is the stronger reducing agent, Ti2+ or Ni2+? Explain.
Problem 57
Problem 58
Do you expect a compound with vanadium in the +2 oxidation state to be an oxidizing or a reducing agent? Explain.
Problem 59
Will a compound that contains a Fe6+ ion be an oxidizing agent or a reducing agent? Explain.
- Arrange the following substances in order of increasing strength as an oxidizing agent, and account for the trend. (a) Cr2+ (b) Cr3+ (c) Cr2O72-
Problem 61
Problem 62a
What is the coordination number of the metal in each of the following complexes?
(a) AgCl2-
(b) [Cr(H2O)5Cl]2+
(c) [Co(NCS)4]2-
Problem 62d
What is the coordination number of the metal in each of the following complexes?
(d) [ZrF8]4-
(e) [Fe(EDTA)(H2O)]-
- What is the coordination number of the metal in each of the following complexes? (a) [Ni(CN)5]3- (b) Ni(CO)4 (c) [Co(en)2(H2O)Br]2+ (d) [Cu(H2O)2(C2O4)2]2- (e) Co(NH3)3(NO2)3
Problem 63
Problem 66
Identify the oxidation state of the metal in each of the following compounds.
(a) Co(NH3)3(NO2)3
(b) [Ag(NH3)2]NO3
(c) K3[Cr(C2O4)2Cl2]
(d) Cs[CuCl2]
Problem 67
Identify the oxidation state of the metal in each of the following compounds.
(a) (NH4)3[RhCl6]
(b) [Cr(NH3)4(SCN)2]Br
(c) [Cu(en)2]SO4
(d) Na2[Mn(EDTA)]
Problem 68
What is the formula, including the charge, for each of the following complexes?
(a) An iridium(III) complex with three ammonia and three chloride ligands
(b) A chromium(III) complex with two water and two oxalate ligands
(c) A platinum(IV) complex with two ethylenediamine and two thiocyanate ligands
Problem 69
What is the formula, including the charge, for each of the following complexes?
(a) An iron(III) complex with six water ligands
(b) A nickel(II) complex with two ethylenediamine and two bromide ligands
(c) A platinum(II) complex with two chloride and two ammonia ligands
Problem 70
Draw the structure of the iron oxalate complex [Fe(C2O4)3]3-. Describe the coordination geometry, and identify any chelate rings. What are the coordination number and the oxidation number of the iron?
- Draw the structure of the platinum ethylenediamine complex [Pt(en)2]2+. Describe the coordination geometry, and identify any chelate rings. What are the coordination number and the oxidation state of the platinum?
Problem 71
Problem 72a
Draw the structure of the following complexes. What are the oxidation state, coordination number, and coordination geometry of the metal in each?
(a) Na[Au(CN)2]
Problem 72b
Draw the structure of the following complexes. What are the oxidation state, coordination number, and coordination geometry of the metal in each?
(b) [Cr(NH3)2(C2O4)2]NO2
Problem 73a
Draw the structure of the following complexes. What are the oxidation state, coordination number, and coordination geometry of the metal in each?
(a) Pt(en)2
Problem 73b
Draw the structure of the following complexes. What are the oxidation state, coordination number, and coordination geometry of the metal in each?
(b) [Co(H2O)5Cl]SO4]
Problem 74
(a) Identify the Lewis acid and the Lewis base in the reaction of ethylenediamine (H2NCH2CH2NH2) with Ni2+ to form [Ni(en)3]2+.
(b) Identify the ligands and donor atoms.
(c) Give the coordination number and geometry of the metal in the complex.
- Identify the Lewis acid and the Lewis base in the reaction of oxalate ions (C2O42-) with Fe3+ to form [Fe(C2O4)3]3-. (a) Identify the ligands and donor atoms. (b) Give the coordination number and geometry of the metal in the complex.
Problem 75