Question 1

Cryolite, Na3AlF6, is mixed with alumina prior to electrolysis in the production of Al because it acts a solute.

Accepted Answer

A) True 
 B)False

Question 2

What effect does increasing temperature have on the conductivities of semiconductors

Accepted Answer

A)  increases 
B)  decreases 
C)  no change 
D)  cannot be predicted 
A)  increases 
B)  decreases 
C)  no change 
D)  cannot be predicted

Question 3

Which of these elements when doped into silicon would give an n-type semiconductor

Accepted Answer

A)  C 
B)  Ga 
C)  P 
D)  Ge 
E)  B 
A)  C 
B)  Ga 
C)  P 
D)  Ge 
E)  B

Question 4

In the Mond process, nickel is purified by

Accepted Answer

A)  dissolving the crude ore in sulfuric acid, and precipitating the nickel(II) ion as the sulfate salt. 
B)  dissolving the crude ore in a lye (NaOH) solution, and precipitating the nickel(II) ion as the hydroxide salt. 
C)  heating the crude ore to its melting point and electrolytically reducing the nickel(II) ions to form the metal. 
D)  passing sodium gas over the crude ore at high temperatures, chemically reducing the nickel(II) to nickel metal. 
E)  passing carbon monoxide over the impure metal at high temperature, forming the volatile Ni(CO)4 which is removed as a gas. 
A)  dissolving the crude ore in sulfuric acid, and precipitating the nickel(II) ion as the sulfate salt. 
B)  dissolving the crude ore in a lye (NaOH) solution, and precipitating the nickel(II) ion as the hydroxide salt. 
C)  heating the crude ore to its melting point and electrolytically reducing the nickel(II) ions to form the metal. 
D)  passing sodium gas over the crude ore at high temperatures, chemically reducing the nickel(II) to nickel metal. 
E)  passing carbon monoxide over the impure metal at high temperature, forming the volatile Ni(CO)4 which is removed as a gas.

Question 5

Which one of these metals would normally be obtained by chemical reduction

Accepted Answer

A)  aluminum 
B)  calcium 
C)  lithium 
D)  sodium 
E)  vanadium 
A)  aluminum 
B)  calcium 
C)  lithium 
D)  sodium 
E)  vanadium

Question 6

Mercury, magnesium, and zinc have low enough boiling points that they can be purified by distillation.

Accepted Answer

A) True 
 B)False

Question 7

The following reaction is used to produce titanium metal at high temperature.TiCl4(g) + 2Mg(l) $\rarr$ Ti(s) + 2MgCl2(l) 
Which element is oxidized and which is reduced

Accepted Answer

A)  Both titanium and magnesium are oxidized 
B)  Titanium is reduced, magnesium is oxidized 
C)  Magnesium is reduced, titanium is oxidized 
D)  Neither titanium or magnesium is oxidized 
E)  None of the above 
A)  Both titanium and magnesium are oxidized 
B)  Titanium is reduced, magnesium is oxidized 
C)  Magnesium is reduced, titanium is oxidized 
D)  Neither titanium or magnesium is oxidized 
E)  None of the above

Question 8

According to the band theory, which of these statements provide(s) an explanation for the high electrical conductivity of metals
I. a partly filled conduction band
II. a valence band overlapping an empty conduction band
III. a filled valence band
IV. a large gap between the valence band and the conduction band

Accepted Answer

A)  I and II 
B)  I and III 
C)  III 
D)  III and IV 
E)  IV 
A)  I and II 
B)  I and III 
C)  III 
D)  III and IV 
E)  IV

Question 9

Which one of these elements has seawater as its commercial source

Accepted Answer

A)  Mg 
B)  Al 
C)  Ca 
D)  Sn 
E)  Cd 
A)  Mg 
B)  Al 
C)  Ca 
D)  Sn 
E)  Cd

Question 10

Aluminum hydroxide, Al(OH)3, is

Accepted Answer

A)  an acid. 
B)  an amphoteric hydroxide. 
C)  a base. 
D)  an explosive hydroxide. 
E)  used to make amalgams. 
A)  an acid. 
B)  an amphoteric hydroxide. 
C)  a base. 
D)  an explosive hydroxide. 
E)  used to make amalgams.

Question 11

The principal reducing agent in a blast furnace is

Accepted Answer

A)  CaO(s) 
B)  CaSiO3(l) 
C)  CO(g) 
D)  O2(g) 
E)  CO2(g) 
A)  CaO(s) 
B)  CaSiO3(l) 
C)  CO(g) 
D)  O2(g) 
E)  CO2(g)

Question 12

Which of the following diagrams represents a semiconductor

Accepted Answer

A)  A 
B)  B 
C)  C 
A)  A 
B)  B 
C)  C

Question 13

The naturally occurring form of a metal that is concentrated enough to allow economical recovery of the metal is known as

Accepted Answer

A)  an element. 
B)  a mineral. 
C)  gangue. 
D)  an ore. 
E)  an amalgam. 
A)  an element. 
B)  a mineral. 
C)  gangue. 
D)  an ore. 
E)  an amalgam.

Question 14

Volatile impurities are removed from ores by means of

Accepted Answer

A)  roasting. 
B)  amalgamation. 
C)  electrolysis. 
D)  flotation. 
E)  zone refining. 
A)  roasting. 
B)  amalgamation. 
C)  electrolysis. 
D)  flotation. 
E)  zone refining.

Question 15

What is the total number of moles (n) of electrons exchanged between the oxidizing agent and the reducing agent in the reaction below to obtain vanadium metal
V2O5(s) + 5Ca(l) $\rarr$ 2V(l) + 5CaO(s)

Accepted Answer

A)  1 
B)  2 
C)  5 
D)  10 
E)  0 
A)  1 
B)  2 
C)  5 
D)  10 
E)  0

Question 16

The equilibrium 3Fe(s) + C(s) $\rarr$Fe3C(s) is established in a solid solution. For such a solution, one can write an equilibrium constant expression in the usual way except that the concentrations that refer to solids in the solid solution are included. Determine the equilibrium constant for the formation of cementite from iron and carbon at 680$\circ$C. (Given: for this reaction at 25$\circ$C, $\Delta$H$\circ$= 21 kJ/mol and $\Delta$S$\circ$ = 20.4 J/mol.K)

Accepted Answer

A)  0.75 
B)  0.33 
C)  3.1 
D)  0.82 
E)  1.2 
A)  0.75 
B)  0.33 
C)  3.1 
D)  0.82 
E)  1.2

Question 17

Bauxite (Al2O3$\times$2H2O) ore is the principal commercial source of aluminum metal.

Accepted Answer

A) True 
 B)False

Question 18

A naturally occurring substance with a range of chemical composition is

Accepted Answer

A)  an element. 
B)  a mineral. 
C)  gangue. 
D)  an ore. 
E)  an amalgam. 
A)  an element. 
B)  a mineral. 
C)  gangue. 
D)  an ore. 
E)  an amalgam.

Question 19

Write the chemical formula of epsomite (sold in pharmacies as Epsom salts).

Accepted Answer

A)  CaSO4$\times$7H2O 
B)  MgSO4$\times$7H2O 
C)  Na2SO4$\times$7H2O 
D)  FeSO4$\times$7H2O 
E)  None of the above 
A)  CaSO4$\times$7H2O 
B)  MgSO4$\times$7H2O 
C)  Na2SO4$\times$7H2O 
D)  FeSO4$\times$7H2O 
E)  None of the above

Question 20

Which one of these elements would give a p-type semiconductor when added to a silicon crystal

Accepted Answer

A)  C 
B)  P 
C)  As 
D)  Ga 
E)  Sb 
A)  C 
B)  P 
C)  As 
D)  Ga 
E)  Sb

Exam 21: Metallurgy and the Chemistry of Metals

Cryolite, Na3AlF6, is mixed with alumina prior to electrolysis in the production of Al because it acts a solute.

What effect does increasing temperature have on the conductivities of semiconductors

Which of these elements when doped into silicon would give an n-type semiconductor

In the Mond process, nickel is purified by

Which one of these metals would normally be obtained by chemical reduction

Mercury, magnesium, and zinc have low enough boiling points that they can be purified by distillation.

The following reaction is used to produce titanium metal at high temperature.TiCl4(g) + 2Mg(l) →\rarr→ Ti(s) + 2MgCl2(l) Which element is oxidized and which is reduced

Which one of these elements has seawater as its commercial source

Aluminum hydroxide, Al(OH)3, is

The principal reducing agent in a blast furnace is

Which of the following diagrams represents a semiconductor

The naturally occurring form of a metal that is concentrated enough to allow economical recovery of the metal is known as

Volatile impurities are removed from ores by means of

What is the total number of moles (n) of electrons exchanged between the oxidizing agent and the reducing agent in the reaction below to obtain vanadium metal V2O5(s) + 5Ca(l) →\rarr→ 2V(l) + 5CaO(s)

Bauxite (Al2O3 ×\times× 2H2O) ore is the principal commercial source of aluminum metal.

A naturally occurring substance with a range of chemical composition is

Write the chemical formula of epsomite (sold in pharmacies as Epsom salts).

Which one of these elements would give a p-type semiconductor when added to a silicon crystal

Chemistry: The Study of Change

Atoms Molecules and Ions

Mass Relationships in Chemical Reactions

Reactions in Aqueous Solutions

Gases

Thermochemistry

Quantum Theory and the Electronic Structure of Atoms

Periodic Relationships Among the Elements

Chemical Bonding I: Basic Concepts

Chemical Bonding II: Molecular Geometry and Hybridization of Atomic

Intermolecular Forces and Liquids and Solids

Physical Properties of Solutions

Chemical Kinetics

Chemical Equilibrium

Acids and Bases

Acid-Base Equilibria and Solubility Equilibria

Entropy Free Energy and Equilibrium

Electrochemistry

Nuclear Chemistry

Chemistry in the Atmosphere

Nonmetallic Elements and Their Compounds

Transition Metals Chemistry and Coordination Compounds

Organic Chemistry

Synthetic and Natural Organic Polymers

Filters

Cryolite, Na₃AlF₆, is mixed with alumina prior to electrolysis in the production of Al because it acts a solute.

The following reaction is used to produce titanium metal at high temperature.TiCl₄(g) + 2Mg(l) $\rarr$ Ti(s) + 2MgCl₂(l) Which element is oxidized and which is reduced

Aluminum hydroxide, Al(OH)₃, is

What is the total number of moles (n) of electrons exchanged between the oxidizing agent and the reducing agent in the reaction below to obtain vanadium metal V₂O₅(s) + 5Ca(l) $\rarr$ 2V(l) + 5CaO(s)

Bauxite (Al₂O₃ $\times$ 2H₂O) ore is the principal commercial source of aluminum metal.