Question 1

What is the number of unpaired electrons in an octahedral,low-spin Mn(II)complex?
A) 0
B) 1
C) 2
D) 3
E) 4

Accepted Answer

The answer of What is the number of unpaired electrons...

Question 2

All of the following complexes will be colored (in the visible)EXCEPT ____. A) [Co(en)₃]²⁺ B) [Fe(CN)₆]^4- C) [Ni(H₂O)₆]²⁺ D) [Sc(NH₃)₆]³⁺ E) [Cu(NH₃)₄]²⁺

Accepted Answer

Scandium exists in the +3 oxidation state, which does not allow for any d-orbital electrons to be present, resulting in no visible color. Therefore, [Sc(NH3)6]3+ is colorless. The other complexes have transition metal ions in higher oxidation states with d-orbital electrons present, allowing for visible colors to be observed.

Question 3

If an octahedral Fe+2 complex is diamagnetic,which of the following sets of conditions best describes the complex? A) Low spin and small Δ_ο B) High spin and large Δ_ο C) Low spin and large Δ_ο D) High spin and small Δ_ο E) None of these

Accepted Answer

Diamagnetism indicates that all electrons are paired, which means that the complex has a low spin configuration. Additionally, since the complex is octahedral, we can use the spectrochemical series to infer that a large value of Δ_ο stabilizes the low spin configuration. Therefore, the correct set of conditions is low spin and large Δ_ο, or option C.

Question 4

Determine the number of unpaired electrons in a Cu+2 tetrahedral complex.
A) Zero
B) One
C) Two
D) Three
E) Four

Accepted Answer

Cu+2 ion has d9 configuration. In the tetrahedral geometry, the d-orbitals are split into two sets, eg and t2g. The 4 ligands occupy the 4 t2g orbitals. Therefore, there are 5 electrons in the eg set. Two of these electrons go into the pairing and the remaining 3 electrons are unpaired. Hence, the number of unpaired electrons in Cu+2 tetrahedral complex is one.

Question 5

The period 6 transition metals have greater densities than either the period 4 or 5 transition metals.An explanation concerns the 4f orbitals,which are filled with electrons just prior to the 5d orbitals.As the 4f orbitals are filled,the radii of the elements decrease.The decrease in size is referred to as the ________ contraction.

Accepted Answer

The answer of The period 6 transition metals have greater...

Question 6

Which of the following statements concerning octahedral coordination complexes is not correct? A) Strong field ligands produce large octahedral ligand field splittings. B) Weak field ligands produce high spin complexes. C) Halide ions are strong field ligands. D) Weak field ligands result in relatively small values for Δ_o. E) A relatively large value for Δ_o causes a complex ion to absorb relatively high energy (shorter wavelength)light.

Accepted Answer

Halide ions are generally considered to be weak field ligands, not strong field ligands as stated in statement C. The other statements are correct. Strong field ligands result in large ligand field splittings and low spin complexes, while weak field ligands result in small ligand field splittings and high spin complexes. The magnitude of Δ_o determines the energy of light absorbed, with larger values resulting in absorption of higher energy (shorter wavelength) light.

Question 7

Which of the following d-block ion electron configurations may be high spin or low spin when placed in an octahedral ligand field? A) [Ar]3d¹ B) [Ar]3d⁹ C) [Ar]3d² D) [Ar]3d⁴ E) [Ar]3d⁸

Accepted Answer

In an octahedral ligand field, a d^4 electron configuration can be either high spin or low spin depending on the strength of the ligands. Strong field ligands cause pairing of electrons (low spin), while weak field ligands do not (high spin).

Question 8

Determine the number of unpaired electrons in an octahedral,high-spin Cr(II)complex.
A) 1
B) 2
C) 3
D) 4
E) 5

Accepted Answer

Cr(II) has an electron configuration of [Ar] 3d^4. In a high-spin octahedral complex, the 3d electrons are distributed as t2g^3 eg^1, resulting in 4 unpaired electrons.

Question 9

EDTA^4-,a hexadentate ligand,is most effective at chelating metal ions when the pH is greater than 12. Explain why low pH decreases the chelating ability of the ligand.

Accepted Answer

The answer of EDTA^4-,a hexadentate ligand,is most effective at chelating...

Question 10

One method of recovering metals from their ores involves aqueous solutions; a second method involves heat.The method involving heat is called ________.

Accepted Answer

The answer of One method of recovering metals from their...

Question 11

Which of the following cations would be expected to be colorless in aqueous solution? A) Cu²⁺ B) Mn³⁺ C) Cr⁴⁺ D) Ni²⁺ E) Ag⁺

Accepted Answer

Ag^+ (Silver ion) is expected to be colorless in aqueous solution because it has a completely filled d orbital (d^10 configuration), which means there are no d-d transitions to absorb visible light, resulting in no color.

Question 12

Determine the number of unpaired electrons in the tetrahedral complex ion [Co(NH₃)₄]²⁺. A) 0 B) 1 C) 2 D) 3 E) 4

Accepted Answer

Cobalt in [Co(NH3)4]2+ is in the +2 oxidation state, meaning it has a d7 electron configuration. In a tetrahedral field, the electrons fill the t2 orbitals first, resulting in three unpaired electrons.

Question 13

The spectrochemical series is an arrangement of
A) ligands in order of their tendency to split the d orbitals of a transition metal ion.
B) coordination compounds in order of increasing octahedral ligand field splitting.
C) complex ions in order of the wavelength of light absorbed.
D) ligands in the order of electronegativity.
E) ligands in order of Lewis basicity.

Accepted Answer

The spectrochemical series is an arrangement of ligands in order of their tendency to split the d orbitals of a transition metal ion.

Question 14

Which of the following is the name of the complex [Cu(NH3)4]SO4?
A) Tetraaminecopper(II)sulfate
B) Tetraaminecopper(III)sulfate
C) Tetrasulfatecopper(II)amine
D) Tetrasulfatecopper(III)amine
E) Tetraaminemonosulfatecopper(II)

Accepted Answer

The complex consists of copper(II) ions coordinated to four ammonia molecules, giving the name tetraaminecopper(II). The sulfate ion is the counterion, so it is named sulfate. Therefore, the correct name for the complex is tetraaminecopper(II)sulfate.

Question 15

The complex ion [NiCl₄]^2- is paramagnetic,but the complex ion [Ni(NH₃)₄]²⁺ is diamagnetic.Why do the magnetic properties of these two nickel complexes differ?

Accepted Answer

The answer of The complex ion [NiCl₄]^2- is paramagnetic,but the...

Question 16

As bound ligands,which of the following causes the largest splitting of d-orbitals? A) phen B) H₂O C) I^- D) CN^- E) C₂O₄^2-

Accepted Answer

The answer of As bound ligands,which of the following causes...

Question 17

The spectrochemical series is CN^- > NO₂^- > en > NH₃ > H₂O > OH^- > F^- >Cl^- > Br^- >I^- Which of the following complexes will absorb visible light of the shortest wavelength? A) [Co(H₂O)₆]³⁺ B) [Co(I)₆]^3- C) [Co(OH)₆]^3- D) [Co(en)₃]³⁺ E) [Co(NH₃)₆]³⁺

Accepted Answer

The complex [Co(I)₆]^3- contains the halogen I-, which is classified as a weak field ligand. Therefore, it will absorb light of the highest energy, which corresponds to the shortest wavelength in the visible region.

Question 18

Phenanthroline (C₁₂H₈N₂)can bind to metal ions using both its ammine groups.It is referred to as a(n)________ ligand,meaning it is "two-toothed."

Accepted Answer

The answer of Phenanthroline (C₁₂H₈N₂)can bind to metal ions using...

Question 19

Which of the following is the number of unpaired electrons in an octahedral high-spin Co+3 complex
A) One
B) Two
C) Three
D) Four
E) Five

Accepted Answer

The answer of Which of the following is the number...

Quiz 23: The Chemistry of the Transition Elements

What is the number of unpaired electrons in an octahedral,low-spin Mn(II) complex?

All of the following complexes will be colored (in the visible) EXCEPT ____.

If an octahedral Fe+2 complex is diamagnetic,which of the following sets of conditions best describes the complex?

Determine the number of unpaired electrons in a Cu+2 tetrahedral complex.

Which of the following statements concerning octahedral coordination complexes is not correct?

Which of the following d-block ion electron configurations may be high spin or low spin when placed in an octahedral ligand field?

Determine the number of unpaired electrons in an octahedral,high-spin Cr(II) complex.

EDTA^4-,a hexadentate ligand,is most effective at chelating metal ions when the pH is greater than 12. Explain why low pH decreases the chelating ability of the ligand.

One method of recovering metals from their ores involves aqueous solutions; a second method involves heat.The method involving heat is called ________.

Which of the following cations would be expected to be colorless in aqueous solution?

Determine the number of unpaired electrons in the tetrahedral complex ion [Co(NH₃) ₄]²⁺.

The spectrochemical series is an arrangement of

Which of the following is the name of the complex [Cu(NH3) 4]SO4?

The complex ion [NiCl₄]^2- is paramagnetic,but the complex ion [Ni(NH₃)₄]²⁺ is diamagnetic.Why do the magnetic properties of these two nickel complexes differ?

As bound ligands,which of the following causes the largest splitting of d-orbitals?

The spectrochemical series is CN^- > NO₂^- > en > NH₃ > H₂O > OH^- > F^- >Cl^- > Br^- >I^- Which of the following complexes will absorb visible light of the shortest wavelength?

Phenanthroline (C₁₂H₈N₂)can bind to metal ions using both its ammine groups.It is referred to as a(n)________ ligand,meaning it is "two-toothed."

Which of the following is the number of unpaired electrons in an octahedral high-spin Co+3 complex

Quiz 23: The Chemistry of the Transition Elements

What is the number of unpaired electrons in an octahedral,low-spin Mn(II) complex?

All of the following complexes will be colored (in the visible) EXCEPT ____.

If an octahedral Fe+2 complex is diamagnetic,which of the following sets of conditions best describes the complex?

Determine the number of unpaired electrons in a Cu+2 tetrahedral complex.

Which of the following statements concerning octahedral coordination complexes is not correct?

Which of the following d-block ion electron configurations may be high spin or low spin when placed in an octahedral ligand field?

Determine the number of unpaired electrons in an octahedral,high-spin Cr(II) complex.

EDTA4-,a hexadentate ligand,is most effective at chelating metal ions when the pH is greater than 12. Explain why low pH decreases the chelating ability of the ligand.

One method of recovering metals from their ores involves aqueous solutions; a second method involves heat.The method involving heat is called ________.

Which of the following cations would be expected to be colorless in aqueous solution?

Determine the number of unpaired electrons in the tetrahedral complex ion [Co(NH3) 4]2+.

The spectrochemical series is an arrangement of

Which of the following is the name of the complex [Cu(NH3) 4]SO4?

The complex ion [NiCl4]2- is paramagnetic,but the complex ion [Ni(NH3)4]2+ is diamagnetic.Why do the magnetic properties of these two nickel complexes differ?

As bound ligands,which of the following causes the largest splitting of d-orbitals?

The spectrochemical series is CN- > NO2- > en > NH3 > H2O > OH- > F- >Cl- > Br- >I- Which of the following complexes will absorb visible light of the shortest wavelength?

Phenanthroline (C12H8N2)can bind to metal ions using both its ammine groups.It is referred to as a(n)________ ligand,meaning it is "two-toothed."

Which of the following is the number of unpaired electrons in an octahedral high-spin Co+3 complex

EDTA^4-,a hexadentate ligand,is most effective at chelating metal ions when the pH is greater than 12. Explain why low pH decreases the chelating ability of the ligand.

Determine the number of unpaired electrons in the tetrahedral complex ion [Co(NH₃) ₄]²⁺.

The complex ion [NiCl₄]^2- is paramagnetic,but the complex ion [Ni(NH₃)₄]²⁺ is diamagnetic.Why do the magnetic properties of these two nickel complexes differ?

The spectrochemical series is CN^- > NO₂^- > en > NH₃ > H₂O > OH^- > F^- >Cl^- > Br^- >I^- Which of the following complexes will absorb visible light of the shortest wavelength?

Phenanthroline (C₁₂H₈N₂)can bind to metal ions using both its ammine groups.It is referred to as a(n)________ ligand,meaning it is "two-toothed."