General Chemistry: Atoms First, 2e (McMurry and Fay)
Chapter 21 Metals and Solid-State Materials
21.1 Multiple Choice Questions
1) What are the most abundant minerals in the earth’s crust?
A) aluminosilicates and silicates
B) chlorides and iodides
C) nitrates and phosphates
D) oxides and sulfides
2) What minerals are important commercial sources of metals?
A) aluminosilicates and silicates
B) chlorides and iodides
C) nitrates and phosphates
D) oxides and sulfides
3) What is a principal commercial ore for the element aluminum?
A) bauxite
B) chalcopyrite
C) chromite
D) hematite
4) What is a principal commercial ore for the element iron?
A) cassiterite
B) cinnabar
C) galena
D) hematite
5) What is the most important copper containing ore?
A) cassitrite
B) chalcopyrite
C) chromite
D) cinnabar
6) What metal is isolated from the ore galena?
A) lead
B) manganese
C) tin
D) zinc
7) What metal is isolated from the ore sphalerite?
A) copper
B) manganese
C) titanium
D) zinc
8) What metal is isolated from the ore rutile and what is the chemical formula of rutile?
A) aluminum, Al2O3 ∙ xH2O
B) manganese, MnO2
C) tin, SnO2
D) titanium, TiO2
9) What statement is inconsistent concerning the correlation of the chemical compositions of the
most common ores with the locations of their metals in the periodic table?
A) Gold and the platinum-group metals (Ru, Os, Rh, Ir, Pd, and Pt) are sufficiently unreactive to
occur commonly as the free metals.
B) The early transition metals on the left side of the d block generally occur as oxides while the
more electronegative, late transition metals on the right side of the d block occur as sulfides.
C) The more electronegative p-block metals are commonly found as oxides and nitrates except
for Al and Sn which are found as sulfides.
D) The s-block metals are found in nature as carbonates, silicates and in the case of Na and K as
chlorides.
10) Which of the following metals occurs in nature principally as oxide ores?
A) Ca
B) Co
C) Cr
D) Cu
11) Which substance is commonly found in nature in an uncombined form?
A) aluminum
B) iron
C) platinum
D) tin
12) Which of the following elements is most likely to occur as a metal sulfide ore?
A) Hf
B) Hg
C) K
D) W
13) Which of the following elements is most likely to naturally occur as a carbonate?
A) Ca
B) Co
C) Cr
D) Cu
14) What is not a metallurgy process?
A) environmental reconstruction of the landscape
B) extraction of metals from their ores
C) making of alloys and metallic composites
D) reduction of the mineral to the free metal
15) Which of the following steps is not always necessary in the extraction of a metal from its
ore?
A) chemical treatment prior to reduction
B) concentration of the ore
C) reduction of the mineral to the free metal
D) refining or purification of the metal
16) What is the concentration process used to separate chalcopyrite (CuFeS2) from its gangue?
A) chemical treatment
B) density differences
C) floatation process
D) magnetic differences
17) How is slag separated from molten ore in a blast furnace?
A) chemical treatment
B) density differences
C) distillation
D) magnetic differences
18) What is the name of the process commonly associated with the isolation and concentration of
Al2O3 from the ore bauxite (Al2O3 ∙ xH2O)?
A) basic oxygen process
B) bayer process
C) contact process
D) mond process
19) The chemical process of roasting is commonly used to facilitate the reduction of which metal
ores?
A) Ag, Cu, and Hg
B) Al, Mg, and Na
C) Au and Pt
D) Fe, Mn, and V
20) When zinc sulfide undergoes roasting, the products are
A) Zn and S.
B) Zn and H2S.
C) ZnO and S.
D) ZnO and SO2.
21) What is not an appropriate method of isolating the metals shown?
A) HgS(s) + O2(g) + heat → Hg(g) + SO2(g)
B) ZnO(s) + C(s) + heat → Zn(g) + CO(g)
C) WO3(s) + 3 H2(g) + heat → W(s) + 3 H2O(g)
D) Al2O3(s) + 2 Cr(s) + heat → Cr2O3(s) + 2 Al(l)
22) How does one commercially reduce the metal oxides or chlorides of sodium and
magnesium?
A) electrolysis of the molten salts
B) high temperature reduction with aluminum
C) high temperature reduction with carbon
D) roasting
23) Which of the following metals is not commonly obtained by electrolysis?
A) Al
B) Li
C) Na
D) Zn
24) Which element is likely to be a principal impurity in zinc ore?
A) cadmium
B) copper
C) gallium
D) nickel
25) What is the chemical process most likely to be used to purify nickel metal?
A) distillation
B) electrorefining
C) reaction with carbon monoxide (a Mond process)
D) reaction with iodine
26) What is the chemical process most likely to be used to purify zirconium metal?
A) distillation
B) electrorefining
C) reaction with carbon monoxide (a Mond process)
D) reaction with iodine
27) What conditions favor the decomposition of Ni(CO)4 into Ni and CO after equilibrium is
established in the reaction that has both ΔH and ΔS being negative?
A) decrease volume
B) increase pressure
C) increase temperature
D) simultaneously increase the pressure and decrease volume
28) Zinc occurs in sulfide ores. How many liters of SO2(g) are produced at STP for each
kilogram of roasted ore that is 70% zinc sulfide?
A) 160 L
B) 230 L
C) 460 L
D) 660 L
29) Steel is a mixture composed primarily of
A) iron and carbon.
B) iron and copper.
C) iron and silicon.
D) iron and sulfur.
30) Why is CaCO3 added to a blast furnace in the steel making process?
A) to give a source of CO2
B) to remove basic oxides from the iron ore
C) to remove silicates from the iron ore
D) to remove unreactive carbon from the iron ore
31) Why is silicon dioxide added to molten iron in the basic oxygen process?
A) to remove acidic oxides from the molten iron
B) to remove manganese oxide from the molten iron
C) to remove phosphates and carbonates from the molten iron
D) to remove trace amounts of carbon from the molten iron
32) What is not a primary ingredient used in the production of iron by the blast furnace process?
A) coke
B) iron ore
C) limestone
D) phosphates and silicates
33) What is not a major component of slag?
A) CaSiO3
B) Ca3(PO4)2
C) Fe2O3
D) MnSiO3
34) In the reaction shown below calcium phosphate slag is formed from a reaction of calcium
oxide with phosphoric anhydride.
6 CaO(s) + P4O10(l) → 2 Ca3(PO4)2(l)
CaO is a(n) ________ oxide, and P4O10 is a(n) ________ oxide.
A) acidic, acidic
B) acidic, basic
C) basic, acidic
D) basic, basic
35) To three significant figures, how many metric tons of iron ore are needed to produce 10,000
metric tons of iron per day in the blast furnace process? Assume that the iron ore is iron(III)
oxide and that the ore is 70.0% pure. The reaction of interest is
A) 14,300 metric tons
B) 20,000 metric tons
C) 20,400 metric tons
D) 30,000 metric tons
36) What terminology best describes the bonding in the following schematic of a metal?
A) ionic bonding
B) covalent bonding
C) electron-sea model
D) crystal model
37) Which metal has maximum filling of bonding molecular orbitals and minimal filling of
antibonding molecular orbitals in its composite s-d band?
A) Au
B) Cs
C) Re
D) W
38) Which of the following is the softest and most maleable?
A) Cu
B) V
C) Ru
D) Mn
39) Which substance is the best conductor of electricity?
A) diamond
B) germanium
C) gold
D) phosphorus
40) Metals are good conductors of heat because
A) the valence electrons are free to move about the crystal lattice.
B) heat is carried as kinetic energy by rapid vibrations from atom to atom in the crystal lattice.
C) metal cations in the crystal are efficient at transporting heat.
D) holes are created in the crystal lattice as electrons enter the conduction band and the holes
conduct the heat while electrons conduct electrical charge.
41) Which one of the following metals is expected to have the highest melting point?
A) Cd
B) Cr
C) Hg
D) Zn
42) Electrical resistance of a metal ________ with increasing temperature.
A) can decrease or increase
B) decreases
C) does not change
D) increases
43) What type of substances exhibit an increase in conductivity with an increase in temperature?
A) both metals and semiconductors
B) only insulators
C) only metals
D) only semiconductors
44) White tin has an electrical conductivity that decreases with increasing temperature, and gray
tin has an electrical conductivity that increases with increasing temperature. Therefore, white tin
is classified as a(n) ________, and gray tin is classified as a(n) ________.
A) insulator, metal
B) metal, insulator
C) metal, semiconductor
D) semiconductor, metal
45) Which of the following is a semiconductor?
A) Al
B) B
C) Ga
D) Pb
46) Which one of the following is an electrical insulator?
A) alumina
B) germanium doped with antimony
C) gold
D) tellurium
47) Which substance is a good semiconductor?
A) diamond
B) germanium
C) gold
D) phosphorus
48) Which substance has a larger band gap than silicon?
A) diamond
B) copper
C) germanium
D) silver
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49) Which element has the largest energy band gap?
A) C (diamond)
B) Si
C) Ge
D) Sn (white)
50) Which element has the smallest energy band gap?
A) C (diamond)
B) Ge
C) Pb
D) Si
51) How would one classify a germanium crystal doped with arsenic?
A) conductor
B) n-type semiconductor
C) p-type semiconductor
D) insulator
52) How would one classify copper mixed with tin?
A) conductor
B) n-type semiconductor
C) p-type semiconductor
D) insulator
53) How would one classify a silicon crystal doped with indium?
A) conductor
B) n-type semiconductor
C) p-type semiconductor
D) insulator
54) Which one of the following is an n-type of semiconductor?
A) alumina
B) germanium doped with antimony
C) germanium doped with boron
D) tellurium
55) Which one of the following is a p-type of semiconductor?
A) germanium doped with antimony
B) germanium doped with boron
C) tellurium
D) YBa2Cu3O7
56) Which combination of semiconductors can be employed to make a diode?
A) GaAs doped with Ge and GaP doped with Si
B) GaAs doped with Se and GaP doped with Zn
C) Si doped with B and Ge doped with Ga
D) Si doped with P and Ge doped with As
57) Which statement about a diode laser is false?
A) Light is emitted when a reverse bias is applied to the p-n junction.
B) Electrons and holes recombine at the p-n junction.
C) A laser cavity reflects the emitted light back and forth to provide stimulated emission.
D) The light emerging from the laser possesses geat intensity, a single frequency, and a single
phase.
58) Photovoltaic cells use light to
A) excite electrons into the conduction band of a n-type semiconductor.
B) excite electrons into the conduction band of a p-type semiconductor.
C) excite holes into the conduction band of a n-type semiconductor.
D) excite electrons into the valence band of a p-type semiconductor.
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59) A light emitting diode with a band gap of 181 kJ/mol emits light in what region of the
electromagnetic radiation spectrum?
A) infrared
B) ultraviolet
C) visible – blue
D) visible – red
60) Which one of the following is a metallic conductor at room temperature but a superconductor
at 18 K?
A) diamond
B) graphite
C) fullerene
D) potassium fulleride
61) A particular superconductor has eight copper atoms on corners and eight copper atoms on
edges of its unit cell. How many copper atoms are attributed to a single unit cell of this
superconductor?
A) 1
B) 3
C) 5
D) 16
62) What is the average oxidation state of Cu in HgCa2Ba2Cu3O8-x if Hg is in the +2 oxidation
state?
A) +1
B) +2
C) -2 – 2x/3
D) +2 + 2x/3
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63) What is the average oxidation number of Cu in the 1-2-3 superconductor YBa2Cu3O7 if Y is
in the +3 oxidation state?
A) +2
B) +2.33
C) +3
D) +3.33
64) Who discovered the phenomenon of superconductivity in 1911?
A) J. G. Bednorz
B) R. B. Fuller
C) K. A. M ller
D) H. K. Onnes
65) What element was found to be the first superconductor of electricity at 4.2 K in 1911?
A) copper
B) iron
C) gallium
D) mercury
66) Below the superconducting transition temperature Tc, superconductors
A) become perfect conductors.
B) become perfect magnets.
C) become perfect resistors.
D) fail to work.
67) What is the Meissner effect associated with superconductors?
A) when the temperature above which the superconductor fails to work
B) when the temperature at which the superconductors become perfect insulators
C) when the net magnetic field within the bulk of the superconductor is zero
D) when the net magnetic field within the bulk of the superconductor becomes nearly infinite
68) What structural features appear necessary for superconductivity in the 1-2-3 YBa2Cu3O7
superconductor?
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A) high metallic character.
B) infinite extended layers of Cu and O atoms and a fractional oxidation state for Cu
C) presence of an inner transition element
D) all of the above statements
69) Which has been found to be a three dimensional superconductor that conducts equally in all
directions?
A) C (diamond)
B) C (graphite)
C) K3C60
D) YBa2Cu3O7
70) Why are ceramics superior to metals as structural materials?
A) Ceramics are easier to fabricate into shapes than metals.
B) Ceramics are more malleable than metals.
C) Ceramics are more resistant to wear and corrosion than metals.
D) Ceramics have greater impact resistance than metals.
71) Which process is used in the fabrication of ceramics?
A) electrolysis
B) reduction
C) roasting
D) sintering
72) Sintering is
A) a filtration process through a molecular sieve.
B) the process of heating particles of a powder below the melting point so that they fuse together.
C) the process of rapid cooling of a material to yield a superconducting mixture.
D) the process of removing metals from ore by passing material through a magnetic field.
73) Why are ceramics so much more brittle than metals?
A) The bonding in ceramics has a very high degree of ionic bonding character.
B) The bonding in ceramics has a very high degree of pi bonding character.