Why is silver used in jewelry and other decorative objects

How is the n value of the d sublevel of a transition element related to the period number of the element?

Write the general electron configuration of a transition element (a) in Period 5; (b) in Period 6.

What is the general rule concerning the order in which electrons are removed from a transition metal atom to form an ion? Give an example from Group 5B(5). Name two types of measurements used to study electron configurations of ions

What is the maximum number of unpaired d electrons that an atom or ion can possess? Give an example of an atom and an ion that have this number

How does the variation in atomic size across a transition series contrast with the change across the main-group elements of the same period? Why?

(a) What is the lanthanide contraction? (b) How does it affect atomic size down a group of transition elements? (c) How does it influence the densities of the Period 6 transition elements?

(a) What is the range in electronegativity across the first (3d) transition series? (b) What is the range across Period 4 of maingroup elements? (c) Explain the difference.

(a) Explain the major difference between the number of oxidation states of most transition elements and that of most mainsiL48593_ch23_1022-1063 12:11:07 13:39pm Page 1058 Apago PDF Enhancer group elements. (b) Why is the 2 oxidation state so common among transition elements?

(a) What behavior distinguishes paramagnetic and diamagnetic substances? (b) Why are paramagnetic ions common among transition elements but not main-group elements? (c) Why are colored solutions of metal ions common among transition elements but not main-group elements?

Using the periodic table to locate each element, write the electron configuration of (a) V; (b) Y; (c) Hg.

Using the periodic table to locate each element, write the electron configuration of (a) Ru; (b) Cu; (c) Ni.

Using the periodic table to locate each element, write the electron configuration of (a) Zn; (b) Mn; (c) Re.

Give the electron configuration and the number of unpaired electrons for (a) Sc3; (b) Cu2; (c) Fe3; (d) Nb3. 23

Give the electron configuration and the number of unpaired electrons for: (a) Cr3; (b) Ti4; (c) Co3; (d) Ta2. 23

What is the highest oxidation state for (a) Ta; (b) Zr; (c) Mn?

What is the highest oxidation state for (a) Nb; (b) Y; (c) Tc?

What is the highest oxidation state for (a) Nb; (b) Y; (c) Tc?

Which transition metals have a maximum O.N. of 6?

Which transition metals have a maximum O.N. of 4?

In which compound does Cr exhibit greater metallic behavior, CrF2 or CrF6? Explain.

VF5 is a liquid that boils at 48C, whereas VF3 is a solid that melts above 800C. Explain this difference in properties.

2 Is it more difficult to oxidize Cr or Mo? Explain.

Is MnO4 or ReO4 a stronger oxidizing agent? Explain.

Which oxide, CrO3 or CrO, is more acidic in water? Why?

Which oxide, Mn2O3 or Mn2O7, is more basic in water? Why?

The green patina of Cu-alloy roofs results from corrosion in the presence of O2, H2O, CO2, and sulfur compounds. The other members of Group 1B(11), Ag and Au, do not form a patina. Corrosion of Cu and Ag in the presence of sulfur compounds leads to a black tarnish, but Au does not tarnish. This pattern is different from that in Group 1A(1), where ease of oxidation increases down the group. Explain these different group patterns.

What atomic property of the lanthanides leads to their remarkably similar chemical properties?

(a) What is the maximum number of unpaired electrons in a lanthanide ion? (b) How does this number relate to occupancy of the 4f subshell?

Which of the actinides are radioactive?

Give the electron configuration of (a) La; (b) Ce3; (c) Es; (d) U4.

Give the electron configuration of (a) Pm; (b) Lu3; (c) Th; (d) Fm3.

Only a few lanthanides show an oxidation state other than 3. Two of these, europium (Eu) and terbium (Tb), are found near the middle of the series, and their unusual oxidation states can be associated with a half-filled f subshell. (a) Write the electron configurations of Eu2, Eu3, and Eu4. Why is Eu2 a common ion, whereas Eu4 is unknown? (b) Write the electron configurations of Tb2, Tb3, and Tb4. Would you expect Tb to show a 2 or a 4 oxidation state? Explain. 23.33 Cer

Cerium (Ce) and ytterbium (Yb) exhibit some oxidation states in addition to 3. (a) Write the electron configurations of Ce2, Ce3, and Ce4. (b) Write the electron configurations of Yb2, Yb3, and Yb4. (c) In addition to the 3 ions, the ions Ce4 and Yb2 are stable. Suggest a reason for this stability. Problem

Which lanthanide has the maximum number of unpaired electrons in both its atom and 3 ion? Give the number of unpaired electrons in the atom and ion.

Why is chromium so useful for decorative electroplating?

What is valence-state electronegativity? Explain the change in acidity of the oxides of Mn with changing O.N. of the metal.

What property does manganese confer to steel?

Why is silver used in jewelry and other decorative objects?

How is a photographic latent image different from the image you see on a piece of developed film?

Why is mercury a liquid? Why does it have a 1 ion?

When a basic solution of Cr(OH)4 ion is slowly acidified, solid Cr(OH)3 precipitates and then redissolves in excess acid. If Cr(OH)4 exists as Cr(H2O)2(OH)4 , write equations that represent these two reactions.

Use the following data to determine if Cr2(aq) can be prepared by the reaction of Cr(s) with Cr3(aq): Cr3(aq) e Cr2(aq) E ? 0.41 V Cr3(aq) 3e Cr(s) E ? 0.74 V Cr2(aq) 2e Cr(s) E ? 0.91 V 23.43 When so

When solid CrO3 is dissolved in water, the solution is orange rather than the yellow of H2CrO4. How does this observation indicate that CrO3 is an acidic oxide?

Solutions of KMnO4 are used in redox titrations because dark purple MnO4 oxidizing agent changes to the faint pink Mn2 as it is reduced. The end point occurs when a slight purple remains as more KMnO4 is added. If a sample that has reached this end point stands for a long time, the purple fades and a suspension of a small amount of brown, muddy MnO2 appears. Use standard electrode potentials to explain this result.

Describe the makeup of a complex ion, including the nature of the ligands and their interaction with the central metal ion. Explain how a complex ion can be positive or negative and how it occurs as part of a neutral coordination compound.

What electronic feature must a donor atom of a ligand have?

What is the coordination number of a metal ion in a complex ion? How does it differ from oxidation number?

What structural feature is characteristic of a chelate?

What geometries are associated with the coordination numbers 2, 4, and 6?

What are the coordination numbers of cobalt(III), platinum(II), and platinum(IV) in complexes?

How is a complex ion a Lewis adduct?

What does the ending -ate signify in a complex ion name?

In what order are the metal ion and ligands given in the name of a complex ion?

Is a linkage isomer a type of constitutional isomer or stereoisomer? Explain.

Give systematic names for the following formulas: (a) [Ni(H2O)6]Cl2 (b) [Cr(en)3](ClO4)3 (c) K4[Mn(CN)6]

Give systematic names for the following formulas: (a) [Co(NH3)4(NO2)2]Cl (b) [Cr(NH3)6][Cr(CN)6] (c) K2[CuCl4]

What are the charge and coordination number of the central metal ion(s) in each compound of Problem 23.55?

What are the charge and coordination number of the central metal ion(s) in each compound of Problem 23.56?

Give systematic names for the following formulas: (a) K[Ag(CN)2] (b) Na2[CdCl4] (c) [Co(NH3)4(H2O)Br]Br2

Give systematic names for the following formulas: (a) K[Pt(NH3)Cl5] (b) [Cu(en)(NH3)2][Co(en)Cl4] (c) [Pt(en)2Br2](ClO4)2

What are the charge and coordination number of the central metal ion(s) in each compound of Problem 23.59?

What are the charge and coordination number of the central metal ion(s) in each compound of Problem 23.60?

Give formulas corresponding to the following names: (a) Tetraamminezinc sulfate (b) Pentaamminechlorochromium(III) chloride (c) Sodium bis(thiosulfato)argentate(I)

Give formulas corresponding to the following names: (a) Dibromobis(ethylenediamine)cobalt(III) sulfate (b) Hexaamminechromium(III) tetrachlorocuprate(II) (c) Potassium hexacyanoferrate(II)

What is the coordination number of the metal ion and the number of individual ions per formula unit in each of the compounds in Problem 23.63?

What is the coordination number of the metal ion and the number of individual ions per formula unit in each of the compounds in Problem 23.64?

Give formulas corresponding to the following names: (a) Hexaaquachromium(III) sulfate (b) Barium tetrabromoferrate(III) (c) Bis(ethylenediamine)platinum(II) carbonate

Give formulas corresponding to the following names: (a) Potassium tris(oxalato)chromate(III) (b) Tris(ethylenediamine)cobalt(III) pentacyanoiodomanganate(II) (c) Diamminediaquabromochloroaluminum nitrate

Give the coordination number of the metal ion and the number of ions per formula unit in each compound in Problem 23.67.

Give the coordination number of the metal ion and the number of ions per formula unit in each compound in Problem 23.68.

Which of these ligands can participate in linkage isomerism: (a) NO2 ; (b) SO2; (c) NO3 ? Explain with Lewis structures.

Which of these ligands can participate in linkage isomerism: (a) SCN; (b) S2O3 2 (thiosulfate); (c) HS? Explain with Lewis structures. 2

For any of the following that can exist as isomers, state the type of isomerism and draw the structures: (a) [Pt(CH3NH2)2Br2] (b) [Pt(NH3)2FCl] (c) [Pt(H2O)(NH3)FCl]

For any of the following that can exist as isomers, state the type of isomerism and draw the structures: (a) [Zn(en)F2] (b) [Zn(H2O)(NH3)FCl] (c) [Pd(CN)2(OH)2] 2

For any of the following that can exist as isomers, state the type of isomerism and draw the structures: (a) [PtCl2Br2] 2 (b) [Cr(NH3)5(NO2)]2 (c) [Pt(NH3)4I2] 2 2

For any of the following that can exist as isomers, state the type of isomerism and draw the structures: (a) [Co(NH3)5Cl]Br2 (b) [Pt(CH3NH2)3Cl]Br (c) [Fe(H2O)4(NH3)2] 2

Chromium(III), like cobalt(III), has a coordination number of 6 in many of its complex ions. Compounds are known that have the traditional formula CrCl3 nNH3, where n ? 3 to 6. Which of the compounds has an electrical conductivity in aqueous solution similar to that of an equimolar NaCl solution?

When MCl4(NH3)2 is dissolved in water and treated with AgNO3, 2 mol of AgCl precipitates immediately for each mole of MCl4(NH3)2. Give the coordination number of M in the complex

Palladium, like its group neighbor platinum, forms fourcoordinate Pd(II) and six-coordinate Pd(IV) complexes. Write modern formulas for the complexes with these compositions: (a) PdK(NH3)Cl3 (b) PdCl2(NH3)2 (c) PdK2Cl6 (d) Pd(NH3)4Cl4

(a) What is a coordinate covalent bond? (b) Is it involved when FeCl3 dissolves in water? Explain. (c) Is it involved when HCl gas dissolves in water? Explain

According to valence bond theory, what set of orbitals is used by a Period 4 metal ion in forming (a) a square planar complex; (b) a tetrahedral complex?

A metal ion uses d2 sp3 orbitals when forming a complex. What is its coordination number and the shape of the complex?

A complex in solution absorbs green light. What is the color of the solution?

In terms of the theory of color absorption, explain two ways that a solution can be blue.

(a) What is the crystal field splitting energy ( )? (b) How does it arise for an octahedral field of ligands? (c) How is it different for a tetrahedral field of ligands?

What is the distinction between a weak-field ligand and a strong-field ligand? Give an example of each.

Is a complex with the same number of unpaired electrons as the free gaseous metal ion termed high spin or low spin?

How do the relative magnitudes of Epairing and affect the paramagnetism of a complex?

Why are there both high-spin and low-spin octahedral complexes but only high-spin tetrahedral complexes?

Give the number of d electrons (n of dn ) for the central metal ion in (a) [TiCl6] 2; (b) K[AuCl4]; (c) [RhCl6] 3.

Give the number of d electrons (n of dn ) for the central metal ion in (a) [Cr(H2O)6](ClO3)2; (b) [Mn(CN)6] 2; (c) [Ru(NO)(en)2Cl]Br.

How many d electrons (n of dn ) are in the central metal ion in (a) Ca[IrF6]; (b) [HgI4] 2; (c) [Co(EDTA)]2?

How many d electrons (n of dn ) are in the central metal ion in (a) [Ru(NH3)5Cl]SO4; (b) Na2[Os(CN)6]; (c) [Co(NH3)4CO3I]?

Sketch the orientation of the orbitals relative to the ligands in an octahedral complex to explain the splitting and the relative energies of the dxy and the orbitals.

The two eg orbitals are identical in energy in an octahedral complex but have different energies in a square planar complex, with the orbital being much lower in energy than the . Explain with orbital sketches.

Which of these ions cannot form both high- and low-spin octahedral complexes: (a) Ti3; (b) Co2; (c) Fe2; (d) Cu2? 23

Which of these ions cannot form both high- and low-spin octahedral complexes: (a) Mn3; (b) Nb3; (c) Ru3; (d) Ni2? 23

Draw orbital-energy splitting diagrams and use the spectrochemical series to show the orbital occupancy for each of the following (assuming that H2O is a weak-field ligand): (a) [Cr(H2O)6] 3 (b) [Cu(H2O)4]

Draw orbital-energy splitting diagrams and use the spectrochemical series to show the orbital occupancy for each of the following (assuming that H2O is a weak-field ligand): (a) [Cr(CN)6] 3 (b) [Rh(CO)6] 3 (c) [Co(OH)6] 4 2

Draw orbital-energy splitting diagrams and use the spectrochemical series to show the orbital occupancy for each of the following (assuming that H2O is a weak-field ligand): (a) [MoCl6] 3 (b) [Ni(H2O)6] 2 (c) [Ni(CN)4] 2 23

Draw orbital-energy splitting diagrams and use the spectrochemical series to show the orbital occupancy for each of the following (assuming that H2O is a weak-field ligand): (a) [Fe(C2O4)3] 3 (C2O4 2 creates a weaker field than H2O does.) (b) [Co(CN)6] 4 (c) [MnCl6] 4 23

Rank the following in order of increasing and energy of light absorbed: [Cr(NH3)6] 3, [Cr(H2O)6] 3, [Cr(NO2)6] 3. 2

Rank the following in order of decreasing and energy of light absorbed: [Cr(en)3] 3, [Cr(CN)6] 3, [CrCl6] 3. 2

A complex, ML6 2, is violet. The same metal forms a complex with another ligand, Q, that creates a weaker field. What color might MQ6 2 be expected to show? Explain.

[Cr(H2O)6]+2 is violet. Another CrL6 complex is green. Can ligand L be CN¯? Can it be Cl¯? Explain.

Octahedral [Ni(NH3)6] 2 is paramagnetic, whereas planar [Pt(NH3)4] 2 is diamagnetic, even though both metal ions are d8 species. Explain.

The hexaaqua complex [Ni(H2O)6] 2 is green, whereas the hexaammonia complex [Ni(NH3)6] 2 is violet. Explain.

Three of the complex ions that are formed by Co3 are [Co(H2O)6] 3, [Co(NH3)6] 3, and [CoF6] 3. These ions have the observed colors (listed in arbitrary order) yellow-orange, green, and blue. Match each complex with its color. Explain. Co

When neptunium (Np) and plutonium (Pu) were discovered, the periodic table did not include the actinides, so these elements were placed in Group 7B(7) and 8B(8). When americium (Am) and curium (Cm) were synthesized, they were placed in Group 8B(9) and 8B(10). However, during chemical isolation procedures, Glenn Seaborg and his group, who had synthesized these elements, could not find their compounds among other compounds of these groups, which led Seaborg to suggest they were part of a new inner transition series. (a) How do the electron configurations of these elements support Seaborgs suggestion? (b) The highest fluorides of Np and Pu are hexafluorides, as is the highest fluoride of uranium. How does this chemical evidence support the placement of Np and Pu as inner transition elements rather than transition elements?

How many different formulas are there for octahedral complexes with a metal M and four ligands A, B, C, and D? Give the number of isomers for each formula and describe the isomers.

At one time, it was common to write the formula for copper(I) chloride as Cu2Cl2, instead of CuCl, analogously to Hg2Cl2 for mercury(I) chloride. Use electron configurations to explain why Hg2Cl2 and CuCl are both correct.

Correct each name that has an error: (a) Na[FeBr4], sodium tetrabromoferrate(II) (b) [Ni(NH3)6] 2, nickel hexaammine ion (c) [Co(NH3)3I3], triamminetriiodocobalt(III) (d) [V(CN)6] 3, hexacyanovanadium(III) ion (e) K[FeCl4], potassium tetrachloroiron(III)

For the compound [Co(en)2Cl2]Cl, give: (a) The coordination number of the metal ion (b) The oxidation number of the central metal ion (c) The number of individual ions per formula unit (d) The moles of AgCl that precipitate immediately when 1 mol of compound is dissolved in water and treated with AgNO3

Hexafluorocobaltate(III) ion is a high-spin complex. Draw the orbital-energy splitting diagram for its d orbitals.

A salt of each of the ions in Table 23.3 (p. 1029) is dissolved in water. A Pt electrode is immersed in each solution and connected to a 0.38-V battery. All of the electrolytic cells are run for the same amount of time with the same current. (a) In which cell(s) will a metal plate out? Explain. (b) Which cell will plate out the least mass of metal? Explain.

Criticize and correct the following statement: strong-field ligands always give rise to low-spin complexes

Two major bidentate ligands used in analytical chemistry are bipyridyl (bipy) and ortho-phenanthroline (o-phen): Draw structures and discuss the possibility of isomers for (a) [Pt(bipy)Cl2] (b) [Fe(o-phen)3] 3 (c) [Co(bipy)2F2] (d) [Co(o-phen)(NH3)3Cl]2 N

The following reaction is a key step in black-and-white photography (see p. 1035): AgBr(s) 2S2O3 2(aq) Ag(S2O3)2 3(aq) Br(aq) During fixing, 258 mL of hypo (sodium thiosulfate) was used. The hypo concentration was 0.1052 M before the AgBr reacted, and 0.0378 M afterward. How many grams of AgBr reacted? 23.

The metal ion in platinum(IV) complexes, like that in cobalt(III) complexes, has a coordination number of 6 and often has Cl ions and NH3 molecules as ligands. For the traditional (before the work of Werner) formulas PtCl4 6NH3 and PtCl4 4NH3, (a) give the modern formula and charge of the complex ion, and (b) predict the moles of ions per mole of compound dissolved and moles of AgCl formed with excess AgNO3.

In 1940, when the elements Np and Pu were prepared, a controversy arose about whether the elements from Ac on were analogs of the transition elements (and related to Y through Mo) or analogs of the lanthanides (and related to La through Nd). The arguments hinged primarily on comparing observed oxidation states to those of the earlier elements. (a) If the actinides were analogs of the transition elements, what would you predict about the maximum oxidation state for U? For Np? (b) If the actinides were analogs of the lanthanides, what would you predict about the maximum oxidation state for U? For Pu?

In many species, a transition metal has an unusually high or low oxidation state. Write balanced equations for the following and find the oxidation state of the transition metal in the product: (a) Iron(III) ion reacts with hypochlorite ion in basic solution to form ferrate ion (FeO4 2), Cl, and water. (b) Potassium hexacyanomanganate(II) reacts with K metal to form K6[Mn(CN)6]. (c) Heating sodium superoxide (NaO2) with Co3O4 produces Na4CoO4 and O2 gas. (d) Vanadium(III) chloride reacts with Na metal under a CO atmosphere to produce Na[V(CO)6] and NaCl. (e) Barium peroxide reacts with nickel(II) ions in basic solution to produce BaNiO3. (f) Bubbling CO through a basic solution of cobalt(II) ion produces [Co(CO)4] , CO3 2, and water. (g) Heating cesium tetrafluorocuprate(II) with F2 gas under pressure gives Cs2CuF6. (h) Heating tantalum(V) chloride with Na metal produces NaCl and Ta6Cl15, in which half of the Ta is in the 2 state. (i) Potassium tetracyanonickelate(II) reacts with hydrazine (N2H4) in basic solution to form K4[Ni2(CN)6] and N2 gas. 23

Draw a Lewis structure with lowest formal charges for MnO4 .

The coordination compound [Pt(NH3)2(SCN)2] displays two types of isomerism. Name the types and give names and structures for the six possible isomers.

In the sepia toning of a black-and-white photograph, the image is converted to a rich brownish violet by placing the finished photograph in a solution of gold(III) ions, in which metallic gold replaces the metallic silver. Use Appendix D to explain the chemistry of this process

An octahedral complex with three different ligands (A, B, and C) can have formulas with three different ratios of the ligands: [MA4BC]n, such as [Co(NH3)4(H2O)Cl]2 [MA3B2C]n, such as [Cr(H2O)3Br2Cl] [MA2B2C2] n, such as [Cr(NH3)2(H2O)2Br2] For each example, give the name, state the type(s) of isomerism present, and draw all isomers.

In black-and-white photography, what are the major chemical changes involved in exposing, developing, and fixing?

In [Cr(NH3)6]Cl3, the [Cr(NH3)6] 3 ion absorbs visible light in the blue-violet range, and the compound is yelloworange. In [Cr(H2O)6]Br3, the [Cr(H2O)6] 3 ion absorbs visible light in the red range, and the compound is blue-gray. Explain these differences in light absorbed and color of the compound.

Dark green manganate salts contain the MnO4 2 ion. The ion is stable in basic solution but disproportionates in acid to MnO2(s) and MnO4 . (a) What is the oxidation state of Mn in MnO4 2, MnO4 , and MnO2? (b) Write a balanced equation for the reaction of MnO4 2 in acidic solution. 23.

Aqueous electrolysis of potassium manganate (K2MnO4) in basic solution is used for the production of tens of thousands of tons of potassium permanganate (KMnO4) annually. (a) Write a balanced equation for the electrolysis reaction. (Water is reduced also.) (b) How many moles of MnO4 can be formed if 12 A flows through a tank of aqueous MnO4 2 for 96 h?

The actinides Pa, U, and Np form a series of complex ions, such as the anion in the compound Na3[UF8], in which the central metal ion has an unusual geometry and oxidation state. In the crystal structure, the complex ion can be pictured as resulting from interpenetration of simple cubic arrays of uranium and fluoride ions. (a) What is the coordination number of the metal ion in the complex ion? (b) What is the oxidation state of uranium in the compound? (c) Sketch the complex ion

Consider the square planar complex shown at right. Which of the structures below are geometric isomers of it?

(a) What are the central metal ions in chlorophyll, heme, and vitamin B12? (b) What similarity in structure do these compounds have?

Several coordination isomers, with both Co and Cr as 3 ions, have the molecular formula CoCrC6H18N12. (a) Give the name and formula of the isomer in which the Co complex ion has six NH3 groups. (b) Give the name and formula of the isomer in which the Co complex ion has one CN and five NH3 groups.

Several coordination isomers have the molecular formula Pt2H12Cl6N4. (a) Give the name and standard formula of the isomer in which the Pt complex ion has six Cl groups and a charge of 2. (b) Give the name and standard formula of the isomer in which the Pt complex ion has four Cl groups and a charge of 2.

A shortcut to finding optical isomers is to see if the complex has a plane of symmetrya plane passing through the metal 1062 Chapter 23 The Transition Elements and Their Coordination Compounds A B C D E F siL48593_ch23_1022-1063 12:11:07 13:39pm Page 1062 Apago PDF Enhancer atom such that every atom on one side of the plane is matched by an identical one at the same distance from the plane on the other side. Any planar complex has a plane of symmetry, since all atoms lie in one plane. Use this approach to determine whether these exist as optical isomers: (a) [Zn(NH3)2Cl2] (tetrahedral); (b) [Pt(en)2] 2; (c) trans-[PtBr4Cl2] 2; (d) trans-[Co(en)2F2] ; (e) cis-[Co(en)2F2] . 23

Werner prepared two compounds by heating a solution of PtCl2 with triethyl phosphine, P(C2H5)3, which is an excellent ligand for Pt. The two compounds gave the same analysis: Pt, 38.8%; Cl, 14.1%; C, 28.7%; P, 12.4%; and H, 6.02%. Write formulas, structures, and systematic names for the two isomers.

Some octahedral complexes have distorted shapes. In some, two metal-ligand bonds that are 180 apart are shorter than the other four. In [Cu(NH3)6] 2, for example, two Cu N bonds are 207 pm long, and the other four are 262 pm long. (a) Calculate the longest distance between two N atoms in this complex. (b) Calculate the shortest distance between two N atoms.

Mercury has a small but significant vapor pressure, and Hg poisoning can occur in poorly ventilated rooms where Hg has been spilled. What is the partial pressure (in torr) of Hg if the maximum concentration at 25C is 20.0 mg/m3 ?

Normal carbonic anhydrase has zinc at its active site (see Figure B23.2, p. 1056). Suggest a structural reason why carbonic anhydrase synthesized with Ni2, Fe2, or Mn2 in place of Zn2 gives an enzyme with less catalytic efficiency. 2

The effect of entropy on reactions is evident in the stabilities of certain complexes. (a) Using the criterion of number of product particles, predict which of the following will be favored in terms of ?Srxn: [Cu(NH3)4] 2(aq) 4H2O(l) [Cu(H2O)4] 2(aq) 4NH3(aq) [Cu(H2NCH2CH2NH2)2] 2(aq) 4H2O(l) [Cu(H2O)4] 2(aq) 2en(aq) (b) Given that the Cu N bond strength is approximately the same in both complexes, which complex will be more stable with respect to ligand exchange in water? Explain. 23.141

The extent of crystal field splitting is often determined from spectra. (a) Given the wavelength (?) of maximum absorption, find the crystal field splitting energy (?), in kJ/mol, for each of the following complex ions: (b) Construct a spectrochemical series for the ligands in the Cr complexes. (c) Use the Fe data to state how oxidation state affects ?. (d) Use the Co, Rh, and Ir data to state how period number affects ?.

You know the following about a coordination compound: (1) The partial empirical formula is KM(CrO4)Cl2(NH3)4. (2) It has A (red) and B (blue) crystal forms. (3) When 1.0 mol of A or B reacts with 1.0 mol of AgNO3, 0.50 mol of a red precipitate forms immediately. (4) After the reaction in (3), 1.0 mol of A reacts very slowly with 1.0 mol of silver oxalate (Ag2C2O4) to form 2.0 mol of a white precipitate. (Oxalate can displace other ligands.) (5) After the reaction in (3), 1.0 mol of B does not react further with 1.0 mol of AgNO3. From this information, determine the following: (a) The coordination number of M (b) The group(s) bonded to M ionically and covalently (c) The stereochemistry of the red and blue forms

Ionic liquids have many new applications in engineering and materials science. The dissolution of the metavanadate ion in chloroaluminate ionic liquids has been studied: VO3 AlCl4 VO2Cl2 AlOCl2 (a) What is the oxidation number of V and Al in each ion? (b) In reactions of V2O5 with HCl, acid concentration affects the product. At low acid concentration, VO2Cl2 and VO3 form: V2O5 HCl VO2Cl2 VO3 H At high acid concentration, VOCl3 forms: V2O5 HCl VOCl3 H2O Balance each equation, and state which, if either, involves a redox process. (c) What mass of VO2Cl2 or VOCl3 can form from 12.5 g of V2O5 and the appropriate concentration of acid? 23.144 The orbi

The orbital occupancies for the d orbitals of several complex ions are diagrammed below. (a) Which diagram corresponds to the orbital occupancy of the cobalt ion in [Co(CN)6] 3? (b) If diagram D depicts the orbital occupancy of the cobalt ion in [CoF6] n , what is the value of n? (c) [NiCl4] 2 is paramagnetic and [Ni(CN)4] 2 is diamagnetic. Which diagrams correspond to the orbital occupancies of the nickel ions in these species? (d) Diagram C shows the orbital occupancy of V2 in the octahedral complex VL6. Can you determine whether L is a strongor weak-field ligand? Explain.