Question 1

The main effect of the biosphere on the chemistry of the earth's crust has been to

Accepted Answer

A)  create a reducing atmosphere. 
B)  create an oxidizing atmosphere. 
C)  increase the relative humidity. 
D)  decrease the relative humidity. 
E)  increase the level of atmospheric carbon dioxide. 
A)  create a reducing atmosphere. 
B)  create an oxidizing atmosphere. 
C)  increase the relative humidity. 
D)  decrease the relative humidity. 
E)  increase the level of atmospheric carbon dioxide. B

Question 2

The purpose of anodizing aluminum is to remove the oxide layer from the metal's surface.

Accepted Answer

A) True 
 B)False  False

Question 3

The final step of the purification of copper involves electrorefining in which copper is separated from nickel and iron by being reduced at the cathode of a cell. Why are nickel and iron not reduced?

Accepted Answer

A)  Their reduction potentials are more positive than copper's. 
B)  Their reduction potentials are more negative than copper's. 
C)  They cannot be deposited on a copper electrode. 
D)  Their reduction potentials are more negative than water's. 
E)  Their reduction requires large overvoltages. 
A)  Their reduction potentials are more positive than copper's. 
B)  Their reduction potentials are more negative than copper's. 
C)  They cannot be deposited on a copper electrode. 
D)  Their reduction potentials are more negative than water's. 
E)  Their reduction requires large overvoltages. B

Question 4

The process that selectively extracts a metal from its ore, by dissolving it, is called

Accepted Answer

A)  roasting. 
B)  leaching. 
C)  smelting. 
D)  flotation. 
E)  hydration. 
A)  roasting. 
B)  leaching. 
C)  smelting. 
D)  flotation. 
E)  hydration.

Question 5

What elements are alloyed to make stainless steel?

Accepted Answer

A)  Fe and C 
B)  Fe and Mn 
C)  Fe and Ni 
D)  Fe and Ni. 
E)  Fe, Cr and Ni 
A)  Fe and C 
B)  Fe and Mn 
C)  Fe and Ni 
D)  Fe and Ni. 
E)  Fe, Cr and Ni

Question 6

The process in which a gaseous substance is converted into a condensed, more usable chemical substance is called

Accepted Answer

A)  differentiation. 
B)  liquefaction. 
C)  fixation. 
D)  deposition. 
E)  remediation. 
A)  differentiation. 
B)  liquefaction. 
C)  fixation. 
D)  deposition. 
E)  remediation.

Question 7

The process used to produce silicon with a purity of more than 99.999999% is called

Accepted Answer

A)  zone refining. 
B)  electrorefining. 
C)  distillation. 
D)  sublimation. 
E)  alloying. 
A)  zone refining. 
B)  electrorefining. 
C)  distillation. 
D)  sublimation. 
E)  alloying.

Question 8

The alkali metals are isolated from non-aqueous systems. Why is this necessary?

Accepted Answer

A)  The electrolysis of aqueous solutions of the alkali metals requires more energy than electrolysis of the molten salts. 
B)  The dissolved alkali earth halides are too reactive to be electrolyzed. 
C)  The aqueous metal ions are more difficult to reduce than water. 
D)  The reduction potentials of the alkali metals are more positive than the reduction potential of water. 
E)  The aqueous metal ions react violently with water. 
A)  The electrolysis of aqueous solutions of the alkali metals requires more energy than electrolysis of the molten salts. 
B)  The dissolved alkali earth halides are too reactive to be electrolyzed. 
C)  The aqueous metal ions are more difficult to reduce than water. 
D)  The reduction potentials of the alkali metals are more positive than the reduction potential of water. 
E)  The aqueous metal ions react violently with water.

Question 9

Plants extract phosphate from the soil

Accepted Answer

A)  by converting it to the dihydrogen phosphate ion by addition of acid to the soil near roots. 
B)  by converting it to phosphoric acid. 
C)  by osmosis. 
D)  by leaching. 
E)  by fixation. 
A)  by converting it to the dihydrogen phosphate ion by addition of acid to the soil near roots. 
B)  by converting it to phosphoric acid. 
C)  by osmosis. 
D)  by leaching. 
E)  by fixation.

Question 10

Transition elements from the left side of the periodic table are generally found as

Accepted Answer

A)  sulfides because they tend to give up bonding electrons and form crystals with high lattice energies with sulfur. 
B)  sulfides because their electronegativities favor formation of covalent bonds with the polarizable sulfide anion. 
C)  oxides because they tend to give up bonding electrons and form crystals with high lattice energies with oxygen. 
D)  oxides because oxygen, with its high electronegativity, forms strong covalent bonds with them. 
E)  the uncombined elements, because they are noble metals. 
A)  sulfides because they tend to give up bonding electrons and form crystals with high lattice energies with sulfur. 
B)  sulfides because their electronegativities favor formation of covalent bonds with the polarizable sulfide anion. 
C)  oxides because they tend to give up bonding electrons and form crystals with high lattice energies with oxygen. 
D)  oxides because oxygen, with its high electronegativity, forms strong covalent bonds with them. 
E)  the uncombined elements, because they are noble metals.

Question 11

Lightning, fires and other atmospheric processes result in the formation of nitric acid, HNO3, from atmospheric N2, O2 and H2O. Write balanced chemical equations to represent the three reactions involved in the formation of HNO3 by this route.

Accepted Answer

Question 12

Nitrogen fixation occurs through atmospheric, industrial, and biological processes. Which of these fixes the most nitrogen?

Accepted Answer

A)  biological 
B)  atmospheric 
C)  industrial 
D)  industrial$\approx$ atmospheric 
E)  industrial $\approx$biological 
A)  biological 
B)  atmospheric 
C)  industrial 
D)  industrial$\approx$ atmospheric 
E)  industrial $\approx$biological

Question 13

Potassium is produced industrially by the reaction Na(l) + K+(l)   Na+(l) + K(g). The reaction is carried out at 850$\degree$C, but the equilibrium Kc constant strongly favors the reactants. Explain how the conditions are manipulated to ensure a good yield of potassium despite the small value of Kc.

Accepted Answer

The gaseous potassium product

Question 14

The most common source for commercial production of aluminum is called

Accepted Answer

A)  aluminite. 
B)  hematite. 
C)  galena. 
D)  cinnabar. 
E)  bauxite. 
A)  aluminite. 
B)  hematite. 
C)  galena. 
D)  cinnabar. 
E)  bauxite.

Question 15

The bond energy in the hydrogen molecule (H2) is greater than that of the tritium molecule (T2).

Accepted Answer

A) True 
 B)False

Question 16

Compared to the asbestos diaphragm-cell used in the chlor-alkali process, list
A) one main advantage and one disadvantage of mercury cells.
B) two important advantages of polymer membrane-cells.

Accepted Answer

a. Purer NaOH product is forme

Question 17

Which of the following reactions is a good small-scale laboratory method for preparation of hydrogen?

Accepted Answer

A)  CH4(g) + H2O(g) $\rightarrow$ CO(g) + 3H2(g) 
B)  3FeCl2(s) + 4H2O(g)$\rightarrow$Fe3O4(s) + 6HCl(g) + H2(g) 
C)  NaH(s) + H2O(l) $\rightarrow$NaOH(aq) + H2(g) 
D)  CO(g) + H2O(g) $\rightarrow$ CO2(g) + H2(g) 
E)  None of these methods is useful. 
A)  CH4(g) + H2O(g) $\rightarrow$ CO(g) + 3H2(g) 
B)  3FeCl2(s) + 4H2O(g)$\rightarrow$Fe3O4(s) + 6HCl(g) + H2(g) 
C)  NaH(s) + H2O(l) $\rightarrow$NaOH(aq) + H2(g) 
D)  CO(g) + H2O(g) $\rightarrow$ CO2(g) + H2(g) 
E)  None of these methods is useful.

Question 18

The kinetic isotope effect is the basis for

Accepted Answer

A)  the radioactivity of tritium. 
B)  isolation of pure D2O. 
C)  tritium's high reactivity. 
D)  the increase in boiling point when comparing hydrogen, deuterium and tritium. 
E)  nuclear power generation. 
A)  the radioactivity of tritium. 
B)  isolation of pure D2O. 
C)  tritium's high reactivity. 
D)  the increase in boiling point when comparing hydrogen, deuterium and tritium. 
E)  nuclear power generation.

Question 19

.

Accepted Answer

A) True 
 B)False

Question 20

The most abundant element in the Earth's crust is:

Accepted Answer

A)  H 
B)  Fe 
C)  Al 
D)  Si 
E)  O 
A)  H 
B)  Fe 
C)  Al 
D)  Si 
E)  O

Exam 22: The Elements in Nature and Industry

The main effect of the biosphere on the chemistry of the earth's crust has been to

The purpose of anodizing aluminum is to remove the oxide layer from the metal's surface.

The final step of the purification of copper involves electrorefining in which copper is separated from nickel and iron by being reduced at the cathode of a cell. Why are nickel and iron not reduced?

The process that selectively extracts a metal from its ore, by dissolving it, is called

What elements are alloyed to make stainless steel?

The process in which a gaseous substance is converted into a condensed, more usable chemical substance is called

The process used to produce silicon with a purity of more than 99.999999% is called

The alkali metals are isolated from non-aqueous systems. Why is this necessary?

Plants extract phosphate from the soil

Transition elements from the left side of the periodic table are generally found as

Lightning, fires and other atmospheric processes result in the formation of nitric acid, HNO3, from atmospheric N2, O2 and H2O. Write balanced chemical equations to represent the three reactions involved in the formation of HNO3 by this route.

Nitrogen fixation occurs through atmospheric, industrial, and biological processes. Which of these fixes the most nitrogen?

The most common source for commercial production of aluminum is called

The bond energy in the hydrogen molecule (H2) is greater than that of the tritium molecule (T2).

Compared to the asbestos diaphragm-cell used in the chlor-alkali process, list A) one main advantage and one disadvantage of mercury cells. B) two important advantages of polymer membrane-cells.

Which of the following reactions is a good small-scale laboratory method for preparation of hydrogen?

The kinetic isotope effect is the basis for

.

The most abundant element in the Earth's crust is:

Keys to the Study of Chemistry

The Components of Matter

Stoichiometry of Formulas and Equations

Three Major Classes of Chemical Reactions

Gases and the Kinetic-Molecular Theory

Thermochemistry: Energy Flow and Chemical Change

Quantum Theory and Atomic Structure

Electron Configuration and Chemical Periodicity

Models of Chemical Bonding

The Shapes of Molecules

Theories of Covalent Bonding

Intermolecular Forces: Liquids, Solids, and Phase Changes

The Properties of Mixtures: Solutions and Colloids

Periodic Patterns in the Main-Group Elements

Organic Compounds and the Atomic Properties of Carbon

Kinetics: Rates and Mechanisms of Chemical Reactions

Equilibrium: the Extent of Chemical Reactions

Acid-Base Equilibria

Ionic Equilibria in Aqueous Systems

Thermodynamics: Entropy, Free Energy, and the Direction of Chemical Reactions

Electrochemistry: Chemical Change and Electrical Work

The Transition Elements and Their Coordination Compounds

Nuclear Reactions and Their Applications

Filters

Lightning, fires and other atmospheric processes result in the formation of nitric acid, HNO₃, from atmospheric N₂, O₂ and H₂O. Write balanced chemical equations to represent the three reactions involved in the formation of HNO₃ by this route.

The bond energy in the hydrogen molecule (H₂) is greater than that of the tritium molecule (T₂).