Question 1

Which one of these complex ions would absorb light with the shortest wavelength

Accepted Answer

The complex ion that would absorb light with the shortest wavelength is the one with the greatest crystal field splitting energy ($\Delta$), which typically involves ligands that are strong field ligands according to the spectrochemical series. Among the given options, the cyanide ligand (CN-) in option D is known to be a strong field ligand, leading to a larger $\Delta$ and thus requiring higher energy (shorter wavelength) light for electronic transitions.

Question 2

Which of these ligands produces the strongest crystal field

Accepted Answer

CO is a strong field ligand due to its ability to donate electrons through its π bond with the metal center. This leads to a greater energy difference between the t2g and eg orbitals, resulting in a stronger crystal field. The other ligands listed, while containing some electronegative atoms, do not have the same electron-donating ability as CO.

Question 3

Two complex ions containing Ni are [Ni(NH₃)₆]²⁺, which is blue, and [Ni(en)₃]²⁺, which is purple. Which one of these statements is true

Accepted Answer

The color of a complex is related to the wavelength of light it absorbs. Since [Ni(en)₃]²⁺ is purple, it absorbs light of a shorter wavelength (higher energy) than [Ni(NH₃)₆]²⁺, which is blue.

Question 4

Which of these ligands produces the weakest crystal field

Accepted Answer

The answer of Which of these ligands produces the weakest...

Question 5

In the complex ion [ML₆]ⁿ⁺, Mⁿ⁺ has seven d electrons and L is a strong field ligand. According to crystal field theory, the magnetic properties of the complex ion correspond to how many unpaired electrons

Accepted Answer

The answer of In the complex ion [ML₆]ⁿ⁺, Mⁿ⁺ has...

Question 6

How many unpaired electrons does the manganese ion have in [Mn(CN)₆]^4-

Accepted Answer

The answer of How many unpaired electrons does the manganese...

Question 7

In the complex ion [ML₆]ⁿ⁺, Mⁿ⁺ has five d electrons and L is a strong field ligand. According to crystal field theory, the magnetic properties of the complex ion correspond to how many unpaired electrons

Accepted Answer

The answer of In the complex ion [ML₆]ⁿ⁺, Mⁿ⁺ has...

Question 8

Which of these complex ions would absorb light with the longest wavelength

Accepted Answer

The wavelength of light absorbed is directly proportional to the energy required to promote an electron from a lower energy level to a higher energy level. In complex ions, the energy required is determined by the strength of the ligand field. The stronger the ligand field, the higher the energy required and the shorter the wavelength of light absorbed. Among the given options, the ligands in complex C (F-) create the strongest ligand field, requiring the highest energy and shortest wavelength of light absorbed. Therefore, complex C would absorb light with the shortest wavelength, and conversely, the longest wavelength of light would be absorbed by the other complexes.

Question 9

Consider the [CoCl₆]^4- ion. Determine which responses are true statements. I. The oxidation number of Co is -4. II. The coordination number of cobalt is 6. III. It is paramagnetic. IV. It is a low-spin complex.

Accepted Answer

II, III. The coordination number of cobalt in this complex is 6, given by the coordination of 4 Cl- ions and 2 H2O molecules (not explicitly shown but implied by the typical composition of such complexes). Cobalt complexes are often paramagnetic due to unpaired electrons in the d orbitals. The oxidation state of Co is not -4; it's typically +2 or +3 in such complexes, making statement I incorrect. Whether it's a high-spin or low-spin complex depends on the ligands and the metal's oxidation state, which isn't clearly defined by the information given, making IV uncertain without more context.

Question 10

The ion [Co(NH₃)₆]²⁺ is octahedral and high spin. This complex is

Accepted Answer

In a high-spin octahedral complex of Co^2+ (d^7 configuration), there are 3 unpaired electrons due to the higher energy required to pair electrons in the eg orbitals compared to the energy difference between the t2g and eg orbitals.

Question 11

In the complex ion [ML₆]ⁿ⁺, Mⁿ⁺ has seven d electrons and L is a weak field ligand. According to crystal field theory, the magnetic properties of the complex ion correspond to how many unpaired electrons

Accepted Answer

The answer of In the complex ion [ML₆]ⁿ⁺, Mⁿ⁺ has...

Question 12

A complex with the composition [MA₂B₂]X₂ is found to have no geometrical isomers. Both A and B are monodentate ligands. The structure of the complex is

Accepted Answer

The complex has the composition [MA₂B₂]X₂, where A and B are monodentate ligands. This suggests that the complex has a total of 6 ligands, which can coordinate to the central metal atom. The central metal atom is denoted by X. The absence of geometrical isomers suggests that there are no cis and trans isomers possible, hence the complex is not square planar or octahedral. Thus, the most likely geometry would be tetrahedral, where four ligands (either all A or all B) lie at the corners of a tetrahedron around the central ion, with the remaining two ligands (either all A or all B) lying perpendicular to the plane formed by the first four ligands.

Question 13

Which of the following complexes has optical (chiral) isomers

Accepted Answer

The complex [Co(en)₂Cl₂]⁺ has optical isomers because it contains two bidentate ethylenediamine (en) ligands, which can create a chiral center around the cobalt ion.

Question 14

The number of geometrical isomers and optical isomers of the complex ion [Co(en)₃]³⁺ are, respectively,

Accepted Answer

The complex ion [Co(en)2Br2]+, where "en" stands for ethylenediamine, a bidentate ligand, can form geometrical isomers due to the arrangement of the Br ligands (cis and trans). However, only the cis form can exhibit optical isomerism, leading to a pair of enantiomers. Therefore, there is 1 geometrical isomer (cis) that is optically active, resulting in 2 optical isomers.

Question 15

Which of the following complexes has optical (chiral) isomers

Accepted Answer

The complex [Co(en)₃]³⁺ has optical isomers because the complex is octahedral and the two ethylenediamine (en) ligands can be arranged in two different ways around the central cobalt atom. This results in a mirror image relationship between the two possible structures, making them optical isomers. Option A, C, D, and E do not have optical isomers.

Question 16

Two well-known complex ions containing Ni are [Ni(H₂O)₆]²⁺, which is green, and [Ni(en)₃]²⁺, which is purple. Which one of these statements is true

Accepted Answer

The crystal field splitting energy is greater for [Ni(en)3]2+ because ethylenediamine (en) is a stronger field ligand than water, leading to a larger splitting and different color absorption.

Question 17

Which of these electron energy level patterns would absorb light with the shortest wavelength

Accepted Answer

The answer of Which of these electron energy level patterns...

Question 18

How many unpaired electrons are there in the complex ion [Mn(CN)₆]^3-

Accepted Answer

To determine the number of unpaired electrons in the complex ion, we need to first determine the oxidation state of Mn. We know that the overall charge of the complex ion is -1, and since CN^- is a charged ligand that contributes -1 charge, we can assume that Mn has an oxidation state of +1.

Next, we need to consider the electron configuration of Mn^+. Mn has a d^5 configuration, and because CN^- is a strong field ligand, it will cause the d orbitals to split into two sets of different energy levels - a lower energy set of three orbitals (t2g) and a higher energy set of two orbitals (eg).

Based on the number of electrons in each set, we can determine that Mn^+ has two unpaired electrons in the eg set. Therefore, the answer is C) 2.

Question 19

In the complex ion [ML₆]ⁿ⁺, Mⁿ⁺ has six d electrons and L is a weak field ligand. According to crystal field theory, the magnetic properties of the complex ion correspond to how many unpaired electrons

Accepted Answer

In a weak field ligand environment, the d electrons in the metal ion do not pair up and remain in the high-spin state. With six d electrons, the electron configuration would be t2g^4 eg^2, resulting in four unpaired electrons.

Question 20

Labile complexes are coordination complexes that

Accepted Answer

Labile complexes are characterized by their ability to undergo rapid ligand exchange reactions, meaning they can easily replace one ligand with another.

Quiz 23: Transition Metals Chemistry and Coordination Compounds

Which one of these complex ions would absorb light with the shortest wavelength

Which of these ligands produces the strongest crystal field

Two complex ions containing Ni are [Ni(NH₃) ₆]²⁺, which is blue, and [Ni(en) ₃]²⁺, which is purple. Which one of these statements is true

Which of these ligands produces the weakest crystal field

In the complex ion [ML₆]ⁿ⁺, Mⁿ⁺ has seven d electrons and L is a strong field ligand. According to crystal field theory, the magnetic properties of the complex ion correspond to how many unpaired electrons

How many unpaired electrons does the manganese ion have in [Mn(CN) ₆]^4-

In the complex ion [ML₆]ⁿ⁺, Mⁿ⁺ has five d electrons and L is a strong field ligand. According to crystal field theory, the magnetic properties of the complex ion correspond to how many unpaired electrons

Which of these complex ions would absorb light with the longest wavelength

Consider the [CoCl₆]^4- ion. Determine which responses are true statements. I. The oxidation number of Co is -4. II. The coordination number of cobalt is 6. III. It is paramagnetic. IV. It is a low-spin complex.

The ion [Co(NH₃) ₆]²⁺ is octahedral and high spin. This complex is

In the complex ion [ML₆]ⁿ⁺, Mⁿ⁺ has seven d electrons and L is a weak field ligand. According to crystal field theory, the magnetic properties of the complex ion correspond to how many unpaired electrons

A complex with the composition [MA₂B₂]X₂ is found to have no geometrical isomers. Both A and B are monodentate ligands. The structure of the complex is

Which of the following complexes has optical (chiral) isomers

The number of geometrical isomers and optical isomers of the complex ion [Co(en) ₃]³⁺ are, respectively,

Which of the following complexes has optical (chiral) isomers

Two well-known complex ions containing Ni are [Ni(H₂O) ₆]²⁺, which is green, and [Ni(en) ₃]²⁺, which is purple. Which one of these statements is true

Which of these electron energy level patterns would absorb light with the shortest wavelength

How many unpaired electrons are there in the complex ion [Mn(CN) ₆]^3-

In the complex ion [ML₆]ⁿ⁺, Mⁿ⁺ has six d electrons and L is a weak field ligand. According to crystal field theory, the magnetic properties of the complex ion correspond to how many unpaired electrons

Labile complexes are coordination complexes that

Quiz 23: Transition Metals Chemistry and Coordination Compounds

Which one of these complex ions would absorb light with the shortest wavelength

Which of these ligands produces the strongest crystal field

Two complex ions containing Ni are [Ni(NH3) 6]2+, which is blue, and [Ni(en) 3]2+, which is purple. Which one of these statements is true

Which of these ligands produces the weakest crystal field

In the complex ion [ML6]n+, Mn+ has seven d electrons and L is a strong field ligand. According to crystal field theory, the magnetic properties of the complex ion correspond to how many unpaired electrons

How many unpaired electrons does the manganese ion have in [Mn(CN) 6]4-

In the complex ion [ML6]n+, Mn+ has five d electrons and L is a strong field ligand. According to crystal field theory, the magnetic properties of the complex ion correspond to how many unpaired electrons

Which of these complex ions would absorb light with the longest wavelength

Consider the [CoCl6]4- ion. Determine which responses are true statements. I. The oxidation number of Co is -4. II. The coordination number of cobalt is 6. III. It is paramagnetic. IV. It is a low-spin complex.

The ion [Co(NH3) 6]2+ is octahedral and high spin. This complex is

In the complex ion [ML6]n+, Mn+ has seven d electrons and L is a weak field ligand. According to crystal field theory, the magnetic properties of the complex ion correspond to how many unpaired electrons

A complex with the composition [MA2B2]X2 is found to have no geometrical isomers. Both A and B are monodentate ligands. The structure of the complex is

Which of the following complexes has optical (chiral) isomers

The number of geometrical isomers and optical isomers of the complex ion [Co(en) 3]3+ are, respectively,

Which of the following complexes has optical (chiral) isomers

Two well-known complex ions containing Ni are [Ni(H2O) 6]2+, which is green, and [Ni(en) 3]2+, which is purple. Which one of these statements is true

Which of these electron energy level patterns would absorb light with the shortest wavelength

How many unpaired electrons are there in the complex ion [Mn(CN) 6]3-

In the complex ion [ML6]n+, Mn+ has six d electrons and L is a weak field ligand. According to crystal field theory, the magnetic properties of the complex ion correspond to how many unpaired electrons

Labile complexes are coordination complexes that

Two complex ions containing Ni are [Ni(NH₃) ₆]²⁺, which is blue, and [Ni(en) ₃]²⁺, which is purple. Which one of these statements is true

In the complex ion [ML₆]ⁿ⁺, Mⁿ⁺ has seven d electrons and L is a strong field ligand. According to crystal field theory, the magnetic properties of the complex ion correspond to how many unpaired electrons

How many unpaired electrons does the manganese ion have in [Mn(CN) ₆]^4-

In the complex ion [ML₆]ⁿ⁺, Mⁿ⁺ has five d electrons and L is a strong field ligand. According to crystal field theory, the magnetic properties of the complex ion correspond to how many unpaired electrons

Consider the [CoCl₆]^4- ion. Determine which responses are true statements. I. The oxidation number of Co is -4. II. The coordination number of cobalt is 6. III. It is paramagnetic. IV. It is a low-spin complex.

The ion [Co(NH₃) ₆]²⁺ is octahedral and high spin. This complex is

In the complex ion [ML₆]ⁿ⁺, Mⁿ⁺ has seven d electrons and L is a weak field ligand. According to crystal field theory, the magnetic properties of the complex ion correspond to how many unpaired electrons

A complex with the composition [MA₂B₂]X₂ is found to have no geometrical isomers. Both A and B are monodentate ligands. The structure of the complex is

The number of geometrical isomers and optical isomers of the complex ion [Co(en) ₃]³⁺ are, respectively,

Two well-known complex ions containing Ni are [Ni(H₂O) ₆]²⁺, which is green, and [Ni(en) ₃]²⁺, which is purple. Which one of these statements is true

How many unpaired electrons are there in the complex ion [Mn(CN) ₆]^3-

In the complex ion [ML₆]ⁿ⁺, Mⁿ⁺ has six d electrons and L is a weak field ligand. According to crystal field theory, the magnetic properties of the complex ion correspond to how many unpaired electrons