Chemistry

Kenneth W. Whitten, Raymond E. Davis, Larry Peck

Chapter 27 Metals II: Properties and Reactions - all with Video Answers

Educators

Chapter Questions

01:52

Problem 1

How do the acidities or basicities of metal oxides vary with oxidation numbers of the same metal?

Adriano Chikande

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02:12

Problem 2

Discuss the general differences in electron configurations of representative elements and $d$ -transition metals.

Adriano Chikande

Numerade Educator

01:36

Problem 3

Compare the extents to which the properties of successive elements across the periodic table differ for representative elements and $d$ -transition metals. Explain.

Adriano Chikande

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02:14

Problem 4

Compare the metals and nonmetals with respect to
(a) number of outer-shell electrons,
(b) electronegativities,
(c) standard reduction potentials, and (d) ionization energies.

Adriano Chikande

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01:13

Compare the melting points of the alkali metals (Group 1A) with the melting points of other metals. Compare the melting points of the alkali metals with each other and relate them to the locations of the elements on the periodic table.

Adriano Chikande

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02:30

Problem 6

Define malleable and ductile.

Ishu Khandelwal

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02:24

Problem 7

(a) What is the meaning of the statement, "alkali metals are corrosive"? (b) Are alkali metal ions corrosive? (c) Are alkali metal ions an important part of your diet?

Adriano Chikande

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02:21

Problem 8

Q Compare the alkali metals with the alkaline earth metals with respect to (a) atomic radii, (b) densities, (c) first ionization energies, and (d) second ionization energies. Explain the comparisons.

Adriano Chikande

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02:21

Problem 9

Compare the alkali metals with the alkaline earth metals with respect to (a) atomic radii, (b) densities, (c) first ionization energies, and (d) second ionization energies. Explain the comparisons.

Adriano Chikande

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01:48

Problem 10

What changes are believed to occur within an atom of an alkali metal (Group 1A) when it reacts with a nonmetal?

Adriano Chikande

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01:37

Problem 11

Which one of the alkaline earth metals (Group $2 \mathrm{~A}$ ) tends to form bonds that have the greatest amount of ionic character?

Adriano Chikande

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01:49

Problem 12

(a) Compare and contrast the physical and chemical properties of the Group 1 A metals with those of the Group $2 \mathrm{~A}$ metals. (b) Compare the periodic trends of the two groups.

Adriano Chikande

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01:17

Problem 13

Write the general outer-electron configurations for atoms of the $1 \mathrm{~A}$ and $2 \mathrm{~A}$ metals. What oxidation state(s) would you predict for these elements? What types of bonding would you expect in most of the compounds of these elements? Why?

Adriano Chikande

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01:47

Problem 14

Write electron configurations (\uparrow\downarrow notation) for (a) Ca, (b) $\mathrm{Ca}^{2+}$ (c) $\mathrm{Mg}$, (d) $\mathrm{Mg}^{2+}$, (e) Sn, (f) $\mathrm{Sn}^{2+},$ and $(\mathrm{g}) \mathrm{Sn}^{4+}$.

Adriano Chikande

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02:15

Problem 15

Write electron configurations (\uparrow\downarrow notation) for (a) Na,
(b) $\mathrm{Na}^{+}$
(c) $\mathrm{Sr}$
(d) $\mathrm{Sr}^{2+}$
(e) $\mathrm{Al}$,
(f) $\mathrm{Al}^{3+}$, and $(\mathrm{g}) \mathrm{Ga}^{3+}$.

Adriano Chikande

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01:37

Problem 16

Are the elements in Groups $1 \mathrm{~A}$ and $2 \mathrm{~A}$ found in the free state in nature? What are the primary sources for these elements?

Adriano Chikande

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01:45

Problem 17

Describe some uses for (a) lithium and its compounds, and (b) sodium and its compounds.

Adriano Chikande

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01:15

Problem 18

Where do the metals of Groups $1 \mathrm{~A}$ and $2 \mathrm{~A}$ fall with respect to $\mathrm{H}_{2}$ in the activity series? What does this tell us about their reactivities with water and acids?

Adriano Chikande

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03:01

Problem 19

Write chemical equations describing the reactions of $\mathrm{O}_{2}$ with each of the alkali and alkaline earth metals. Account for differences within each family.

Adriano Chikande

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02:55

Problem 20

Describe some uses for (a) calcium and its compounds, and (b) magnesium and its compounds.

Adriano Chikande

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01:06

Problem 21

Write general equations for reactions of alkali metals with (a) hydrogen, (b) sulfur, and (c) ammonia. Represent the metal as $M$.

Adriano Chikande

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01:39

Problem 22

Write general equations for reactions of alkali metals with (a) water, (b) phosphorus, and (c) halogens. Represent the metal as $M$ and the halogen as $X$.

Adriano Chikande

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01:04

Problem 23

Write general equations for reactions of alkaline earth metals with (a) hydrogen, (b) sulfur, and (c) ammonia. Represent the metal as $M$.

Adriano Chikande

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01:38

Problem 24

Write general equations for reactions of alkaline earth metals with (a) water, (b) phosphorus, and (c) chlorine. Represent the metal as $M$.

Adriano Chikande

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02:03

Problem 25

Just as lithium (Li) and its compounds are more like magnesium (Mg) and its compounds than they are like other elements in the lithium family (Group $1 \mathrm{~A}$ ), beryllium (Be) is more like aluminum (Al) than it is like the other elements in Group $2 \mathrm{~A},$ and boron $(\mathrm{B})$ is more like silicon (Si) than it is like the other elements in Group $3 \mathrm{~A}$. What are some ways in which beryllium is similar to aluminum? What are some ways in which boron is similar to silicon?

Adriano Chikande

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02:05

Problem 26

Give some illustrations of diagonal similarities in the periodic table, and explain each.

Adriano Chikande

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01:26

Problem 27

What is hydration energy? How does it vary for cations of the alkali metals?

Adriano Chikande

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01:49

Problem 28

How do hydration energies vary for cations of the alkaline earth metals?

Adriano Chikande

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01:50

Problem 29

How do the standard reduction potentials of the alkali metal cations vary? Why?

Adriano Chikande

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02:01

Problem 30

How do the standard reduction potentials of the alkali metal cations vary? Why?

Adriano Chikande

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01:46

Problem 31

Why are the standard reduction potentials of lithium and beryllium out of line with respect to group trends?

Adriano Chikande

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05:27

Problem 32

- Calculate $\Delta H^{0}$ values at $25^{\circ} \mathrm{C}$ for the reactions of $1 \mathrm{~mol}$ of each of the following metals with stoichiometric quantities of water to form metal hydroxides and hydrogen: (a) $\mathrm{Li},(\mathrm{b}) \mathrm{K},$ and (c) Ca. Rationalize the differences in these values.

Adriano Chikande

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01:25

Problem 33

How are the $d$ -transition metals distinguished from other elements?

Adriano Chikande

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01:37

Problem 34

What are the general properties of the $d$ -transition metals?

Adriano Chikande

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01:52

Problem 35

Why are trends in variations of properties of successive $d$ -transition metals less regular than trends among successive representative elements?

Adriano Chikande

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01:55

Problem 36

Write out the electron configurations for the following species: (a) $\mathrm{Sc},(\mathrm{b}) \mathrm{Fe}$
(c) Cu,
(d) $\mathrm{Zn}^{2+}$
(e) $\mathrm{Cr}^{3+}$
(f) $\mathrm{Ni}^{2+}$
(g) $\mathrm{Ag}$, and $(\mathrm{h}) \mathrm{Ag}^{+}$.

Adriano Chikande

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01:21

Problem 37

Why do copper and chromium atoms have "unexpected" electron configurations?

Adriano Chikande

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02:08

Problem 38

Discuss the similarities and differences among elements of corresponding A and B groups of the periodic table, $3 \mathrm{~A}$ and $3 \mathrm{~B}$ for example.

Adriano Chikande

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01:25

Problem 39

Write electron configurations for the common oxidation states of (a) silver, and (b) gold.

Adriano Chikande

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01:12

Problem 40

What two properties listed in Table $27-1$ suggest that the Group 1A metals are very unlikely to occur as free metals?

Adriano Chikande

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01:48

Problem 41

What two properties listed in Table $27-1$ suggest that the Group 1A metals are very unlikely to occur as free metals?

Adriano Chikande

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01:40

Problem 42

For a given transition metal in different oxidation states, how does the acidic character of its oxides increase? How do ionic and covalent characters vary? Characterize a series of metal oxides as examples.

Adriano Chikande

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01:50

Problem 43

For different transition metals in the same oxidation state in the same group (vertical column) of the periodic table, how do covalent character and acidic character of their oxides vary? Why? Cite evidence for the trends.

Adriano Chikande

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01:39

Problem 44

Chromium(VI) oxide is the acid anhydride of which two acids? Write their formulas. What is the oxidation state of the chromium in these acids?

Adriano Chikande

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02:27

Problem 45

Use the data in Tables $27-1$ and $27-3$ to explain your answers to the following questions. (a) What is the trend of ease of formation of $1+$ ions by the Group 1 A metals? (b) What is the trend of ease of formation of $1+$ ions by the Group $2 \mathrm{~A}$ metals? (c) What is the trend of ease of formation of $2+$ ions by the Group $2 \mathrm{~A}$ metals? (d) Which metals more easily form $1+$ ions- those in Group $1 \mathrm{~A}$ or in Group $2 \mathrm{~A}$ ? (e) Which metals more easily form $2+$ ionsthose in Group $1 \mathrm{~A}$ or in Group $2 \mathrm{~A}$ ?

Adriano Chikande

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06:01

Problem 46

In Appendix $\mathrm{H}$, look up the solubility product constants for $\mathrm{Mg}(\mathrm{OH})_{2}, \mathrm{Ca}(\mathrm{OH})_{2}, \mathrm{Sr}(\mathrm{OH})_{2},$ and $\mathrm{Ba}(\mathrm{OH})_{2}$. The solubility product constant for $\mathrm{Be}(\mathrm{OH})_{2}$ is about $7 \times 10^{-22} .$ Calculate the $\left[\mathrm{OH}^{-}\right]$ and the $\mathrm{pOH}$ of saturated solutions of each of these compounds. Based upon this information, which of these compounds are strong bases? Which compound can form solutions that are slightly basic, but not enough to call it a strong base? Which one cannot produce more hydroxide ions than the autoionization of water? Relate the base strengths to the relative locations of the metals on the periodic table.

Adriano Chikande

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01:12

Problem 47

Among the $d$ -transition metals, the elements of Group $1 \mathrm{~B}$ $(\mathrm{Cu}, \mathrm{Ag},$ and $\mathrm{Au})$ are sometimes referred to as the "coinage metals." Why? What properties do they have that make them particularly useful for this purpose?

Adriano Chikande

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01:25

Problem 48

What is the mass percent of chromium in the chloride salt of $\left[\mathrm{Cr}\left(\mathrm{H}_{2} \mathrm{O}\right)_{5}(\mathrm{OH})\right]^{2+} ?$

Adriano Chikande

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01:25

Problem 49

Some of the oxides of the transition metals are amphoteric. (a) What is meant by the term amphoteric? (b) Identify five oxides that are amphoteric, five oxides that are basic, and five oxides that are acidic.

Adriano Chikande

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01:05

Problem 50

Some of the oxides of the transition metals are amphoteric.
(a) What is meant by the term amphoteric? (b) Identify five oxides that are amphoteric, five oxides that are basic, and five oxides that are acidic.

Adriano Chikande

Numerade Educator

01:24

Problem 51

Magnesium and some of the magnesium alloys will burn if heated to a high enough temperature. Some magnesium alloys are used in construction and may have to be welded at a high temperature. Suggest techniques or requirements for welding these alloys so that they do not ignite.

Adriano Chikande

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01:18

Problem 52

Some mental disorders are treated with medications that contain lithium salts. Why is pure lithium unsuitable for such purposes?

Adriano Chikande

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01:21

Problem 53

Gallium thermometers are high-temperature thermometers. (a) Why can't they be used near room temperature? (b) Propose a reason why mercury thermometers cannot be used to measure temperatures in the upper range of gallium thermometers.

Adriano Chikande

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01:33

Problem 54

How are the maximum oxidation states for the metals in Groups $3 \mathrm{~B}$ through $7 \mathrm{~B}$ related to the locations of the elements on the periodic table?

Adriano Chikande

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02:27

Problem 55

Describe the change in the acid/base character of oxides of the same $d$ -transition metal as the oxidation state of the metal changes from its minimum value to its maximum value.

Adriano Chikande

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03:37

Problem 56

A How many grams of $\mathrm{Co}_{3} \mathrm{O}_{4}$ (a mixed oxide, $\mathrm{CoO}$. $\left.\mathrm{Co}_{2} \mathrm{O}_{3}\right)$ must react with excess aluminum to produce 190. g of metallic cobalt, assuming $67.5 \%$ yield?
$$3 \mathrm{Co}_{3} \mathrm{O}_{4}+8 \mathrm{Al} \stackrel{\text { heat }}{\longrightarrow} 9 \mathrm{Co}+4 \mathrm{Al}_{2} \mathrm{O}_{3}$$

Adriano Chikande

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04:16

Problem 57

A Calculate $\Delta H^{0}, \Delta S^{0}$, and $\Delta G^{0}$ for the reaction of $1 \mathrm{~mol}$ of Na with water to form aqueous $\mathrm{NaOH}$ and hydrogen.

Adriano Chikande

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04:43

Problem 58

$\mathbf{A}$ Calculate $\Delta H^{0}, \Delta S^{0},$ and $\Delta G^{0}$ for the reaction of $1 \mathrm{~mol}$ of $\mathrm{Rb}$ with water to form aqueous $\mathrm{RbOH}$ and hydrogen. Compare the spontaneity of this reaction with that in Exercise 57 .

Adriano Chikande

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04:48

Problem 59

What is the ratio of $\left[\mathrm{Cr}_{2} \mathrm{O}_{7}^{2-}\right]$ to $\left[\mathrm{CrO}_{4}^{2-}\right]$ at $25^{\circ} \mathrm{C}$ in a solution prepared by dissolving $1.5 \times 10^{-3} \mathrm{~mol}$ of sodium chromate, $\mathrm{Na}_{2} \mathrm{CrO}_{4},$ in enough of an aqueous solution buffered at $\mathrm{pH}=2.00$ to produce $235 \mathrm{~mL}$ of solution?

Adriano Chikande

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02:51

Problem 60

A An unknown compound is known to be the carbonate of either a Group $1 \mathrm{~A}$ or a Group $2 \mathrm{~A}$ element. Repeated heating of 14.78 grams of the unknown produced a total of $4.48 \mathrm{~L}$ of carbon dioxide at $0^{\circ} \mathrm{C}$ and 1 atm pressure $(101 \mathrm{kPa}) .$ Calculate the number of moles of $\mathrm{CO}_{2}$ produced, and identify the unknown compound.

Adriano Chikande

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02:26

Problem 61

Write the balanced formula unit, total ionic equations, and net ionic equations for the following. Include state designations in your answers $-(\mathrm{s}),(\mathrm{aq}),$ etc. (a) The reaction of beryllium with a solution of sodium hydroxide. (b) The reaction of calcium with water. (c) The reaction of aluminum with sodium hydroxide.

Adriano Chikande

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02:56

Problem 62

Write the balanced formula unit, total ionic equations, and net ionic equations for the following. Include state designations in your answers-(s), (aq), etc. (a) The reaction of magnesium with steam.
(b) The reaction of rubidium with water. (c) The reaction of chromium(III) hydroxide with a solution of sodium hydroxide.

Adriano Chikande

Numerade Educator

01:54

Problem 63

Open www.saltinstitute.org or a site dealing with the salt industry. (a) Name three states within the United States that have rock salt mines. (b) Of the sodium chloride mined (solid or solution), what percent of it is used to de-ice roads? (c) Name the two important products in the chemical industries that depend upon sodium chloride as a starting material.

Adriano Chikande

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01:48

Problem 64

Water- and air-sensitive chemicals are often stored and handled inside a "glove box" filled with a dry, inert gas, typically nitrogen or argon. Which of these two gases would be the better choice for a glove box used to handle lithium metal? Why? Are there other metals with the same problem?

Adriano Chikande

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04:01

Problem 65

Use the Environmental Protection Agency's web site (http://www.epa.gov) or an internet search engine (such as http://www.google.com) to research information on lead poisoning.
(a) What is the greatest source of concern for children's lead poisoning in homes? What are other sources of exposure? (b) What year was the main usage of lead in
(a) banned by the federal government? (c) What two metal ions, when present in food, help protect the body from absorbing lead? Why might this be?

Susan Hallstrom

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