Question 1

In coordination compounds, the term used to
Refer to the number of ligands bound to the metal is:

Accepted Answer

Coordination number refers to the number of ligands bound to the metal ion in a coordination compound.

Question 2

Which metal has the largest heat of vaporization?

Accepted Answer

Chromium (Cr) has the largest heat of vaporization among the given metals due to its strong metallic bonds and high melting and boiling points.

Question 3

The name of the coordination compound Na[FeCl₄] is:

Accepted Answer

The name of the complex uses the stock system for naming coordination compounds. The first part of the name is the cation, Na+, and is named as sodium. The anion, [FeCl₄], contains a central metal ion, Fe and four ligands, Cl-, and two tridentate ligands (₄). The oxidation state of the Fe ion can be determined by summing up the oxidation states of the ligands and the charge of the anion (which is 1- in this case). Chlorine (Cl) always has an oxidation state of -1. Each of the tridentate ligands has three sulfur atoms that are connected to each other in a ring, with a total charge of -2. The ligand is named as tris(thio-1,2-ethanediolato)iron(III). Thus, the overall charge of the complex is 1-. The name of the complex is sodium tetrachloroferrate(III).

Question 4

What is the oxidation state of cobalt in the compound [Co(NH₃)₄Cl₂]Cl?

Accepted Answer

The compound given is [Co(NH3)5Cl]Cl. In this coordination complex, ammonia (NH3) is a neutral ligand and does not contribute to the oxidation state of cobalt. Chloride (Cl) inside the complex contributes -1. The overall charge of the complex is +1 (from the extra Cl- outside the coordination sphere). To balance this, the oxidation state of cobalt must be +3.

Question 5

What is the oxidation state of the ruthenium ion in the compound, K₂[RuCl₅(H₂O)]?

Accepted Answer

Ruthenium has a charge of +3 from the Cl ligand, and a charge of -2 from the HS(O) ligand. Thus, the overall oxidation state of Ru in the complex is +1.

Question 6

Which of these metals is not a transition element?

Accepted Answer

Transition elements are the elements located in the middle of the periodic table, specifically in groups 3-12. Calcium (Ca) is located in group 2 and is not considered a transition element.

Question 7

Which of these transition elements has the largest atomic radius?

Accepted Answer

Hf (Hafnium) has the largest atomic radius among the given transition metals. This is because Hafnium has the highest atomic number (72) and as we move from left to right in a period, atomic radius decreases due to the increase in the number of protons in the nucleus, leading to a stronger attractive force on the electrons. However, within a group, from top to bottom, atomic radius increases due to the addition of a new shell of electrons. Therefore, Hf being at the bottom of the group has the largest atomic radius.

Question 8

What is the coordination number of the central atom in the coordination compound [Co(en)₂Br₂]⁺? (en = H₂NCH₂CH₂NH₂)

Accepted Answer

The coordination compound given is [Co(en)3]3+, where en (ethylenediamine) is a bidentate ligand, meaning it binds through two sites. Since there are three en ligands, each providing two coordination sites, the coordination number of Co is 6.

Question 9

The maximum oxidation state of a transition metal is usually observed when it is combined with:

Accepted Answer

Oxygen and fluorine are highly electronegative elements that can pull electrons away from the transition metal, allowing it to reach its maximum oxidation state.

Question 10

Which metal listed below has the highest melting point?

Accepted Answer

Chromium (Cr) has the highest melting point among the options listed.

Question 11

The highest oxidation state expected for Ti is:

Accepted Answer

Titanium has 4 valence electrons in its outermost shell, which allows it to form up to 4 covalent bonds with other elements. Therefore, the highest oxidation state expected for Ti is +4.

Question 12

Given the three statements below, select the correct choice.
I. The lanthanide contraction causes Nb and Ta to have the same atomic radius.
II. The lanthanide contraction causes the radius of Zr to be greater than the radius of Ti.
III. The lanthanide contraction causes the first ionization energy of W to be larger than that of Mo.

Accepted Answer

The lanthanide contraction results in Nb and Ta having similar atomic radii (I is true) and increases the ionization energy of W compared to Mo (III is true). However, it does not cause Zr to have a greater radius than Ti (II is false).

Question 13

What is the oxidation state of the nickel ion in the compound [Ni(CO)₄]?

Accepted Answer

In [Ni(CO)4], carbon monoxide (CO) is a neutral ligand, meaning it does not change the oxidation state of the metal it is coordinated to. Therefore, the oxidation state of nickel in this compound is 0.

Question 14

What is the coordination number of the central atom in the coordination compound [Pt(NH₃)₄Cl₂]SO₄?

Accepted Answer

The coordination number of the central atom in the coordination compound [Pt(NH₃)₄Cl₂]SO₄ is 6. This is because the central atom, Pt, is bonded to six other atoms or ions: four NH₃ molecules and two Cl ions.

Question 15

Which of these metals is not a transition element?

Accepted Answer

Aluminum (Al) is not a transition element according to its electron configuration, which has a full valence shell of electrons in the third energy level (3s23p1). Transition metals have incomplete d sublevels, which contribute to their unique properties such as variable oxidation states and colorful compounds.

Question 16

The formula of potassium pentacyanocarbonylcobaltate(III) is:

Accepted Answer

The correct formula for potassium pentacyanocarbonylcobaltate(III) is K[Co(CN)5(CO)]. The subscript III indicates the oxidation state of cobalt, which is +3 in this compound. The correct formula unit reflects the number and type of ions or molecules present in the compound. Option C is the only one that correctly represents the compound with the appropriate number and types of atoms and ions. The other options either have incorrect subscripts or include additional atoms or ions that are not present in the compound.

Question 17

Which of the statements are true of ligands?

Accepted Answer

Ligands are Lewis bases because they donate an electron pair to the metal ion to form a coordinate covalent bond.

Question 18

Which of these transition elements has the largest atomic radius?

Accepted Answer

As we move from left to right across a period in the periodic table, the atomic radius generally decreases due to increasing effective nuclear charge. However, within a group, the atomic radius generally increases as we move down the group due to the addition of a new energy level. Ta (tantalum) is in the same group as Cr (chromium) and Co (cobalt), but it is located below them in the periodic table, which means it has an additional energy level compared to Cr and Co. Therefore, Ta has the largest atomic radius among the given transition elements. Re (rhenium) and Os (osmium) are in a different group, so they can be eliminated as answer choices.

Question 19

The highest oxidation state expected for Nb is:

Accepted Answer

The highest oxidation state for any transition metal is equal to its group number. Nb is in group 5, so the highest oxidation state expected for Nb is +5.

Question 20

Which of these metals is not a transition element?

Accepted Answer

Zn (Zinc) is not considered a transition element because it does not have partially filled d orbitals in its most common oxidation state. Transition elements are defined by their partially filled d orbitals, but zinc, in its common +2 oxidation state, has a completely filled d orbital (3d^10 configuration), distinguishing it from true transition metals.

Quiz 19: Transition Metals, Coordination Chemistry and Metallurgy

In coordination compounds, the term used to Refer to the number of ligands bound to the metal is:

Which metal has the largest heat of vaporization?

The name of the coordination compound Na[FeCl₄] is:

What is the oxidation state of cobalt in the compound [Co(NH₃) ₄Cl₂]Cl?

What is the oxidation state of the ruthenium ion in the compound, K₂[RuCl₅(H₂O) ]?

Which of these metals is not a transition element?

Which of these transition elements has the largest atomic radius?

What is the coordination number of the central atom in the coordination compound [Co(en) ₂Br₂]⁺? (en = H₂NCH₂CH₂NH₂)

The maximum oxidation state of a transition metal is usually observed when it is combined with:

Which metal listed below has the highest melting point?

The highest oxidation state expected for Ti is:

What is the oxidation state of the nickel ion in the compound [Ni(CO) ₄]?

What is the coordination number of the central atom in the coordination compound [Pt(NH₃) ₄Cl₂]SO₄?

Which of these metals is not a transition element?

The formula of potassium pentacyanocarbonylcobaltate(III) is:

Which of the statements are true of ligands?

Which of these transition elements has the largest atomic radius?

The highest oxidation state expected for Nb is:

Which of these metals is not a transition element?

Quiz 19: Transition Metals, Coordination Chemistry and Metallurgy

In coordination compounds, the term used to Refer to the number of ligands bound to the metal is:

Which metal has the largest heat of vaporization?

The name of the coordination compound Na[FeCl4] is:

What is the oxidation state of cobalt in the compound [Co(NH3) 4Cl2]Cl?

What is the oxidation state of the ruthenium ion in the compound, K2[RuCl5(H2O) ]?

Which of these metals is not a transition element?

Which of these transition elements has the largest atomic radius?

What is the coordination number of the central atom in the coordination compound [Co(en) 2Br2]+? (en = H2NCH2CH2NH2)

The maximum oxidation state of a transition metal is usually observed when it is combined with:

Which metal listed below has the highest melting point?

The highest oxidation state expected for Ti is:

What is the oxidation state of the nickel ion in the compound [Ni(CO) 4]?

What is the coordination number of the central atom in the coordination compound [Pt(NH3) 4Cl2]SO4?

Which of these metals is not a transition element?

The formula of potassium pentacyanocarbonylcobaltate(III) is:

Which of the statements are true of ligands?

Which of these transition elements has the largest atomic radius?

The highest oxidation state expected for Nb is:

Which of these metals is not a transition element?

The name of the coordination compound Na[FeCl₄] is:

What is the oxidation state of cobalt in the compound [Co(NH₃) ₄Cl₂]Cl?

What is the oxidation state of the ruthenium ion in the compound, K₂[RuCl₅(H₂O) ]?

What is the coordination number of the central atom in the coordination compound [Co(en) ₂Br₂]⁺? (en = H₂NCH₂CH₂NH₂)

What is the oxidation state of the nickel ion in the compound [Ni(CO) ₄]?

What is the coordination number of the central atom in the coordination compound [Pt(NH₃) ₄Cl₂]SO₄?