Deck 9: The D-Block Elements

Question 1

What is the formula of the compound formed when potassium dichromate is dissolved in aqueous base?

A) K₂CrO₄
B) K₂Cr₂O₇
C) CrO₃
D) Cr(OH)₃

Answer 1

A

Question 2

Most d-block elements have only one common oxidation state.

Answer 2

False

Question 3

Which of the following is likely to be a good reducing agent?

A) Cr₂O₇^2-
B) MnO₄^-
C) Cr²⁺
D) MnO₂
E) Cr₂O₃

Answer 3

Cr²⁺

Question 4

The lanthanide contraction results because

A) the shielding effect of the d-electrons is less than that of the f-electrons.
B) the shielding effect of the d-electrons is greater than that of the f-electrons.
C) of the poor shielding effect of the f-electrons and the higher nuclear charge.
D) the d-electrons shield the f-electrons from the nucleus.
E) f-electrons interact more strongly with each other than d-electrons.

Question 5

Except for scandium and titanium,all the 3d transition metals form divalent ions in aqueous solution.

Question 6

The maximum oxidation states for chromium and manganese are

A) both +7.
B) +7 and +8, respectively.
C) +3 and +4, respectively.
D) +5 and +6, respectively.
E) +6 and +7, respectively.

Question 7

For a given metal,the oxides become more basic with increasing oxidation state.

Question 8

For the oxides CrO, Cr₂O₃, And CrO₃,
Which of the following is true?

A) All the oxides are basic.
B) All the oxides are acidic.
C) CrO is acidic, and Cr₂O₃ and CrO₃ are basic.
D) CrO and Cr₂O₃ are acidic and CrO₃ is basic.
E) CrO is basic, Cr₂O₃ is amphoteric, and CrO₃ is acidic.

Question 9

Of the following, which possesses the smallest atomic radius?

A) Cd
B) Zn
C) Mo
D) Pd
E) Ru

Question 10

Which of the following is expected to be the best oxidizing agent?

A) Cu⁺(aq)
B) Ti³⁺(aq)
C) CrO₄^2-(aq)
D) VO₂⁺
E) Cr²⁺(aq)

Question 11

Which of the following would be the strongest acid in aqueous solution?

A) Mg(OH₂)₆²⁺(aq)
B) V(OH₂)₆²⁺(aq)
C) Ni(OH₂)₆²⁺(aq)
D) Sc(OH₂)₆³⁺(aq)
E) Fe(OH₂)₆²⁺(aq)

Question 12

The atomic radii of the Period 6 d-metals are

A) smaller than expected, and about the same as the Period 5 d-metals.
B) about the same as the lanthanides.
C) larger than the atomic radii of the Period 5 d-metals.
D) about the same as the Period 4 d-metals.
E) large because of the lanthanide contraction.

Question 13

Which of the following pairs have about the same atomic radius?

A) Cu and Ag
B) Co and Rh
C) Fe and Ru
D) Mn and Tc
E) Ru and Os

Question 14

The d-metals can be mixed together to form a wide range of alloys because

A) the d-electrons interact strongly with each other.
B) the d-metals have a wide range of metal radii.
C) the nucleus is well shielded by the d-electrons.
D) the range of d-metal radii is not very great.
E) the d-metals have low melting points.

Question 15

Vanadium metal is produced by the

A) reduction of VOCl₂(s) with magnesium.
B) reduction of vanadium(V) oxide with calcium.
C) reaction of V₂O₅(s) with coke.
D) decomposition of VCl₄(g) at high temperature.
E) roasting of VO₂(s).

Question 16

The metalloproteins hemoglobin and vitamin B₁₂ contain the metals

A) iron and zinc, respectively.
B) cobalt and nickel, respectively.
C) iron and Mo, respectively.
D) manganese and iron, respectively.
E) iron and cobalt, respectively.

Question 17

Which of the following oxides is likely to be acidic?

A) Mn₂O₇
B) MnO₂
C) Mn₂O₇ and MnO
D) Mn₂O₃
E) MnO

Question 18

In the d-block elements, the third-row metallic radii are about the same as the second-row radii because of

A) the lanthanide contraction.
B) the third-row metallic radii are greater than the second-row radii.
C) the increased number of d-electrons.
D) greater shielding of f-electrons.
E) greater shielding of d-electrons.

Question 19

The properties of the transition metals vary greatly but they all have

A) high densities and high melting points.
B) the same physical properties.
C) oxides that are used to produce alloys.
D) low boiling points.
E) the same strength as their alloys.

Question 20

Which of the following is likely to be a good oxidizing agent?

A) Fe²⁺
B) Cr²⁺
C) V²⁺
D) Mn²⁺
E) MnO₄^-

Question 21

Both Cu²⁺(aq)and Zn²⁺(aq)are colorless.

Question 22

The formulas of mercury(I) and mercury(II)Chloride are

A) Hg₂Cl₃ and HgCl₂, respectively.
B) Hg₂Cl₂ and HgCl₂, respectively.
C) HgCl and HgCl₂, respectively.
D) Hg₂Cl and HgCl₂, respectively.
E) Hg₂Cl₂ and HgCl, respectively.

Question 23

All of the following ligands are monodentate except

A) ammine.
B) cyano.
C) aqua.
D) carbonyl.
E) oxalato.

Question 24

One mole of pentaamminechlorocobalt(III)chloride dissolves in water to give _____ moles of ions.

Question 25

When one mole of trans-tetraamminedichlorocobalt(III) chloride dissolves in water,How many moles of ions does it produce?

A) 1 mole of ions.
B) 2 moles of ions.
C) 3 moles of ions.
D) 4 moles of ions.

Question 26

How many geometric isomers are possible for the complex ion[Co(NH₃)₃(OH₂)₃]³⁺?

A) 4
B) 1
C) 0
D) 2
E) 3

Question 27

Sulfur dioxide is removed from copper ores in the smelting of copper by the reaction
SO₂(g) + CaO(s) $\rightarrow$ CaSO₃(s)
What is the Lewis base in this reaction? What is the Lewis acid?

Question 28

What is the name of the complex [Cr(en)₂(OH₂)Cl]Cl₂?

A) diethylenediaminebis(aquachloro)chromium(III) chloride
B) Aquachlorobis(ethylenediamine)chromium(III) chloride
C) Chloroaquabis(ethylenediamine)chromate(III) chloride
D) Aquachlorobis(ethylenediamine)chromium(II) dichloride
E) Aquachloridebis(ethylenediamine)chromium(III) chloride

Question 29

How many geometric isomers are possible for the complex[Co(en)(OH₂)Cl₃]?

A) 3
B) 2
C) 4
D) 5
E) 0

Question 30

Zinc is used to galvanize iron.Explain why a galvanized container should not be used to store sodium hydroxide.

Question 31

Complexes with coordination number 4 are either tetrahedral or octahedral.

Question 32

What is the oxidation number of iron in K₃[Fe(CN)₆]?

A) +3
B) +2
C) +9
D) +6

Question 33

In the complex [Fe(CN)₆]^4-,

A) iron is a Lewis acid and cyanide is a Lewis base.
B) Cyanide is a Lewis acid.
C) iron has an oxidation number of +3.
D) Cyanide has an oxidation number of -2.

Question 34

Which of the following is the formula of potassium hexacyanoferrate(II)?

A) [Fe(CN)₆]
B) K[Fe(CN)₆]
C) K₂[Fe(CN)₆]
D) K₃[Fe(CN)₆]
E) K₄[Fe(CN)₆]

Question 35

The ligand 4-cyanopyridine can form _____ complex(es)with penataamminecobalt(III).

Question 36

For the complex ion [Rh(NCS)₂(NH₃)₄]⁺ , how many different isomers of all types are possible?

A) 2
B) 3
C) 4
D) 6
E) 8

Question 37

What is the name of the complex Na[Co(NH₃)₃Cl₃]?

A) Sodium triamminetrichlorocobaltate(II)
B) Sodium triamminetrichlorocobalt(III)
C) Sodium tris(aminechloro)cobaltate(II)
D) Sodium triamminetrichlorocobalt(II)
E) Sodium trichlorotriamminecobalt(III)

Question 38

A ligand is

A) a Lewis base.
B) necessary in a complex to balance the charge on the metal ion.
C) used to force octahedral geometry on a metal ion.
D) a Lewis acid.
E) used to precipitate metal ions from aqueous solution.

Question 39

Which of the following are ionization isomers?

A) cis-[CoCl₂(en)₂]Cl and trans-[CoCl₂(en)₂]Cl
B) [Cr(NH₃)₆][Fe(CN)₆] and [Fe(NH₃)₆][Cr(CN)₆]
C) [CrCl(OH₂)₅]Cl₂.H₂O and [CrCl₂(OH₂)₄]Cl.2H₂O
D) [CoBr(NH₃)₅]SO₄ and [CoSO₄(NH₃)₅]Br
E) [CoNCS(NH₃)₅]Cl₂ and [CoSCN(NH₃)₅]Cl₂

Question 40

What is the oxidation number of cobalt in [CoCl(NH₃)₅]Cl₂?

A) +4
B) +1
C) +6
D) +2
E) +3

Question 41

Consider the complexes fac- and mer-triaquatrichlororuthenium(III)
chloride.Neither of these complexes is chiral.

Question 42

How many unpaired electrons are predicted for [Mn(CN)₆]^4-?

A) 1
B) 2
C) 3
D) 5
E) 0

Question 43

The complex [Ru(OH₂)₃Cl₃]

A) is chiral.
B) has 2 geometric isomers, neither of which is chiral.
C) has 2 geometric isomers, one of which is chiral.
D) has 2 geometric isomers, both of which are chiral.
E) has no geometric isomers.

Question 44

Which of the following complexes is chiral?

A) trans-[Cr(en)₂Cl₂]⁺
B) cis-[Cr(en)₂Cl₂]⁺
C) cis-[Cr(NH₃)₄Cl₂]⁺
D) trans-[Cr(en)₂(NH₃)Cl]²⁺
E) [Co(OH₂)₃(NH₃)₃]³⁺

Question 45

Which of the following complexes is (are) chiral?

A) 4
B) 3
C) 1 and 3
D) 2
E) 1 and 2

Question 46

For the complex ion[Co(en)(NH₃)₂(OH₂)Cl]²⁺, there are four possible geometric isomers.How many of these geometric isomers are optically active?

A) none
B) 3
C) all of them
D) 1
E) 2

Question 47

Which of the following complexes is chiral?

A) [Co(en)₃]³⁺
B) [RuCl₃(CN)₃]^3-
C) [Co(NH₃)₆]³⁺
D) trans-[Cr(en)₃]³⁺

Question 48

Which of the following complexes is (are) chiral?

A) 4
B) 1 and 3
C) 2
D) 3
E) 1

Question 49

The cationic complex [Co(OH₂)₆]²⁺ should have how many unpaired electrons?

A) 0
B) 1
C) 2
D) 3
E) 4

Question 50

Which of the following complex ions is colorless?

A) [Cr(OH₂)₆]³⁺
B) [Ti(OH₂)₆]³⁺
C) [Ni(OH₂)₆]²⁺
D) [V(OH₂)₆]²⁺
E) [Zn(OH₂)₆]²⁺

Question 51

Consider the following data:
$\begin{array} { l l } { \text { Complex } }& { \text { Absorbance maximum } } \\ { \mathrm { Ti } \left( \mathrm { OH } _ { 2 } \right) 6 ^ { 3 + } } &510 \mathrm {~nm}\\\mathrm { Fe } \left( \mathrm { OH } _ { 2 } \right) 6 ^ { 3 + } & 700 \mathrm {~nm} \\\mathrm { Fe } ( \mathrm { CN } ) 6 ^ { 4 - } & 305 \mathrm {~nm}\end{array}$

Which complex has the largest ligand field splitting?

Question 52

Which of the following complex ions has the smallest d-orbital splitting energy?

A) [CoCl₄]^2-
B) [CoCl₆]^4-
C) [Co(NH₃)₆]²⁺
D) [Co(OH₂)₆]²⁺
E) [Co(CN)₆]^4-

Question 53

For which one of the following would it not be possible to distinguish between high-spin and low-spin complexes in octahedral geometry?

A) Cr(II)
B) Co(III)
C) Co(II)
D) Fe(II)
E) Ni(II)

Question 54

Which of the following complexes has the smallest d-orbital splitting energy?

A) Co(NH₃)₆³⁺
B) Co(NH₃)₅OH²⁺
C) Co(NH₃)₅CN²⁺
D) Co(NH₃)₅I²⁺
E) Co(NH₃)₅(OH₂)³⁺

Question 55

Which of the following complexes is (are) chiral?

A) 1
B) 4
C) None of the complexes is chiral.
D) 2
E) 2 and 3

Question 56

Which of the following complex ions is likely to absorb at 600-700 nm?

A) [Co(OH₂)₆]²⁺
B) [Co(NO₂)₆]^4-
C) [Co(NH₃)₆]²⁺
D) [Co(CN)₆]^4-
E) [CoCl₄]^2-

Question 57

Which of the following complex ions has the largest d-orbital splitting energy?

A) [Co(NH₃)₆]³⁺
B) [Co(CN)₆]^3-
C) [Co(ox)₃]^3-
D) [CoCl₆]^3-
E) [Co(OH₂)₆]³⁺

Question 58

There are two geometric isomers of tris(glycinato)cobalt(III).Neither of these isomers is chiral.

Question 59

Which of the following complex ions is likely to absorb at about 400 nm?

A) [Cr(OH₂)₆]³⁺
B) [Cr(CN)₆]^3-
C) [CrF₆]^3-
D) [CrCl₆]^3-
E) [Cr(ox)₃]^3-

Question 60

How many geometric isomers are possible for tris(glycinato)cobalt(III)?

A) 5
B) 2
C) 0
D) 3
E) 4

Question 61

Why is $\Delta$ _T always less than $\Delta$ _O?

A) There are two more ligands surrounding the metal.
B) There are two fewer ligands surrounding the metal.
C) The d-orbitals do not point directly at the ligands.
D) None of the above.
E) Both B and C.

Question 62

The complex ion [Cr(OH₂)₆]²⁺ has four unpaired electrons .This means that

A) the complex is high-spin.
B) the complex is diamagnetic.
C) the water ligands are difficult to remove.
D) the complex is low-spin.
E) $\Delta \circ$ is very large.

Question 63

How many unpaired electrons are expected for Co(OH₂)₆²⁺?

A) 0
B) 2
C) 4
D) 1
E) 3

Question 64

The compound Co(en)₂(NO₂)₂Cl has been prepared in a number of isomeric forms.All the forms have the nitrite ion coordinated trough the nitrogen atom.Draw the structure of each isomeric form.
a)One form is optically inactive and does not react with AgNO₃ or en.
b)A second form reacts with AgNO₃ but not with en and is also optically inactive.
c)A third form is optically active and reacts with both AgNO₃ and en.

Question 65

How many unpaired electrons are predicted for a tetrahedral iron (II) complex?

A) 5 or 1, depending on the ligands.
B) 0 or 4, depending on the ligands.
C) 1
D) 4
E) 5

Question 66

If AgNO₃(aq)is added to a 1 M aqueous solution of pentaamminechlorocobalt(III)chloride,how many moles of silver chloride are precipitated?

Question 67

Consider the complex trans-[Co(NH₃)₄Cl₂]Cl.Draw the structure of the complex and clearly label or give the following.
a)The inner and outer coordination spheres
b)The coordination number
c)The trans ligands
d)How many stereoisomers are there for a complex with the formula [Co(NH₃)₄Cl₂]Cl?

Question 68

What is the d-electron configuration of the tetrahedral complex ion [FeCl₄]^-?

A) e²t³
B) e⁴t¹
C) e⁵
D) e¹t⁴
E) e³t²

Question 69

Comparing [Co(CN)₆]^3- with [CoCl₆]^4-, which of the following statements is true?

A) [Co(CN)₆]^3-has more d-electrons than [CoCl₆]^4-.
B) [Co(CN)₆]^3- is paramagnetic while [CoCl₆]^4- is diamagnetic.
C) Both complexes are paramagnetic.
D) [Co(CN)₆]^3- is diamagnetic while [CoCl₆]^4- is paramagnetic.
E) [Co(CN)₆]^3- has the same number of d-electrons as [CoCl₆]^4-.

Question 70

rhodium complexes are high spin?

Question 71

The ligand CN^- is a strong-field ligand because it is a ____________________ and Cl^- is a weak-field ligand because it is a ____________________.

Question 72

Which of the following is diamagnetic?

A) [Fe(OH₂)₆]²⁺
B) [Fe(CN)₆]^3-
C) [Co(OH₂)₆]²⁺
D) [Co(NH₃)₆]³⁺
E) [Cr(NH₃)₆]³⁺

Question 73

All of the following complexes are low-spin except

A) Co(CN)₆^3-.
B) Co(NH₃)₆³⁺.
C) Rh(NH₃)₆³⁺.
D) Co(en)₃³⁺.
E) CoCl₄^2-.

Question 74

A $\pi$ -bonding ligand always gives a larger ligand field splitting energy than a $\sigma$ -bonding ligand.

Question 75

A complex that is the subject of a great deal of research because of its high oxidation potential is ferrate, FeO₄^2-.How many unpaired electrons are in this complex?

A) 4
B) 2
C) 1
D) 6
E) 3

Question 76

All of the following complexes are high-spin except

A) V(OH₂)₆³⁺.
B) Zn(OH₂)₆²⁺.
C) Ni(OH₂)₆²⁺.
D) Co(OH₂)₆²⁺.
E) Fe(OH₂)₆³⁺.

Question 77

Which complex,[CoBr₄]²1^- or [Co(NH₃)₅]³⁺,is the more highly colored?

Question 78

Rhodium lies below cobalt in the periodic table .What is the d-electron configuration of [Rh(CN)₆]^3-?

A) t_2g⁵e_g²
B) t_2g⁴e_g¹
C) t_2g⁶
D) t_2g⁴e_g²
E) t_2g⁵

Question 79

The complex CoCl₄^2- absorbs light at approximately ____________ nm and its color is ____________.

Question 80

How many unpaired electrons are there in [CoBr₄]^2-?

A) 0
B) 2
C) 3
D) 4