CHM 116 C. 23

Which mineral contains aluminum? A) bauxite B) malachite C) cinnabar D) galena E) magnetite

A) bauxite

The oxidation state of copper in Cu₂S is __________. A) +6 B) +2 C) +4 D) 0 E) +1

E) +1

In the second and third transition series, the maximum oxidation state is __________. A) +2 B) +4 C) +5 D) +7 E) +8

E) +8

24 karat gold contains __________% gold. A) 24 B) 25 C) 5.0x10¹ D) 75 E) 1.0x10²

E) 1.0x10²

At high temperatures, carbon can be used as a reducing agent for metal oxides. What is the coefficient of carbon in the balanced equation for the production of manganese and CO₂ from manganese(II) oxide? A) 1 B) 2 C) 3 D) 5 E) 4

A) 1

Roasting HgS in the presence of oxygen produces the free metal and SO₂. What is the coefficient of HgS when the equation for this reaction is completed and balanced? A) 1 B) 2 C) 3 D) 5 E) 4

A) 1

Which statement about steel is false? A) It is a polymer. B) It is an alloy of iron. C) It can have different percentages of carbon. D) It can be made so it resists rust. E) none of the above

A) It is a polymer

A mineral is A) a solid inorganic compound that contains one or more metals. B) a vitamin. C) metal in its elemental form. D) a transition metal ion. E) source of carbon.

A) a solid inorganic compound that contains one or more metals.

Steel is A) an alloy of iron. B) pure iron. C) oxidized iron. D) a mixture of iron and silver. E) a liquid at room temperature.

A) an alloy of iron

The undesirable material that is separated from an ore during the concentration process is called __________. A) gangue B) leachate C) slag D) flocculent E) silicate

A) gangue

Intermetallic compounds are examples of A) homogeneous alloys. B) heterogeneous alloys. C) interstitial alloys. D) solution alloys. E) ionic compounds.

A) homogeneous alloys

Smelting is A) melting and subsequent reaction of molten ores resulting in the formation of layers. B) heating an ore to make it react with a gas in a furnace. C) thermal decomposition of an ore with elimination of a gaseous product. D) addition of calcium to a molten ore. E) cooling a molten metal to make it solidify.

A) melting and subsequent reaction of molten ores resulting in the formation of layers

A substance with unpaired electrons will be A) slightly attracted to a magnet. B) slightly repelled by a magnet. C) permanently magnetic. D) brightly colored. E) nonmetallic.

A) slightly attracted to a magnet

Calcium chloride is added to sodium chloride prior to melting it for electrolysis in a Downs cell __________. A) to lower the melting point B) to increase the concentration of chloride ions C) to make the sodium ions easier to reduce D) to make the chloride ions easier to oxidize E) to provide calcium ions which serve as the cathode

A) to lower the melting point

Part of the Bayer process involves the digestion of crushed ore in concentrated aqueous sodium hydroxide. This process carried out at high pressure __________. A) to prevent boiling B) to prevent formation of iron hydroxide C) to prevent formation of aluminum hydroxide D) to accelerate formation of iron hydroxide E) to lower the boiling temperature of the mixture

A) to prevent boiling

In the Bayer process, the purpose of filtration after the ore has been digested in concentrated sodium hydroxide is __________. A) to separate the soluble aluminum complex from the insoluble iron impurities B) to separate the insoluble aluminum oxide from the soluble iron impurity C) to separate the aluminum metal from the hydroxide ions D) to remove the sodium ions from the sodium hydroxide solution E) to remove the anode sludge

A) to separate the soluble aluminum complex from the insoluble iron impurities

What is the purpose of adding zinc powder to a solution of Au(CN)₂⁻? A) to precipitate the cyanide-gold complex B) to reduce the gold in the cyanide complex to gold metal C) to precipitate the cyanide ion D) to oxidize the gold in the cyanide complex to gold metal E) to form a gold-zinc alloy

B) to reduce the gold in the cyanide complex to gold metal

The purpose of a converter in steel production is __________. A) to reduce the iron in the ore to elemental B) to remove impurity elements by oxidation C) to allow the formation of phosphides within the metal for added corrosion resistance D) to allow the addition of nitrogen for increased strength E) to allow slow solidification of the molten metal so it will purify as it crystallizes

B) to remove impurity elements by oxidation

Hydrometallurgy is A) the use of water to cool molten metals. B) the use of high temperature processes to concentrate and refine metals. C) the use of water to locate underground ore deposits. D) the use of aqueous solutions to extract metals from their ores. E) the use of high temperature processes to make alloys.

D) the use of aqueous solutions to extract metals from their ores.

Which one of the following is a property of most metals? A) low melting point B) brittleness C) high electronegativity D) thermal conductivity E) acidic oxides

D) thermal conductivity

Gold and the platinum group metals are found in nature in metallic form because A) they are solids at room temperature. B) they are highly reactive. C) they are soluble in water. D) they are relatively inert. E) they are relatively abundant.

D) they are relatively inert.

When hydrogen gas is used to reduce an ore (as in a blast furnace), it is converted to __________. A) ammonia B) helium C) hydrogen peroxide D) water E) hydroxide

D) water

The maximum oxidation state in the first transition series is __________. A) +2 B) +4 C) +5 D) +7 E) +8

D)+7

Which one of the following is not true about transition metals? A) They frequently have more than one common oxidation state. B) Their compounds are frequently colored. C) Their compounds frequently exhibit magnetic properties. D) They are found in the d-block of the periodic table. E) They typically have low melting points.

E) They typically have low melting points

Shape memory alloys __________. A) change their structure as the temperature changes B) in their lower temperature phase have a flexible arrangement between atoms C) in their higher temperature phase have strong and fixed bonds between atoms D) are more pliable when cold than when warm E) all of the above

E) all of the above

The purpose of burning coke in a blast furnace is A) to produce reducing gases. B) to produce heat. C) to produce carbon monoxide gas. D) to produce hydrogen gas. E) all of the above

E) all of the above

Which of the following is not an alloy? A) brass B) steel C) sterling silver D) dental amalgam E) ceramic

E) ceramic

The hydrated manganese(II) ion is A) orange. B) blue. C) yellow. D) violet. E) colorless.

E) colorless

Selectively dissolving a metal-containing compound from an ore is called __________. A) converting B) sol formation C) refining D) oxidation E) leaching

E) leaching

The lithosphere is the A) deepest part of the ocean. B) portion of the atmosphere closest to the Earth. C) molten core of the Earth. D) portion of the atmosphere furthest from the Earth. E) solid surface of the Earth.

E) solid surface of the Earth.

Which property of metals cannot be explained with the electron-sea model? A) shine B) high thermal conductivity C) high electric conductivity D) malleability and ductility E) trends in melting points

E) trends in melting points

Sodium metal cannot be produced by electrolysis of an aqueous solution of sodium chloride because __________ A) the carbon anode is more easily reduced than sodium ions. B) water is more easily oxidized than sodium metal. C) the production of chlorine gas interferes with the reduction of sodium ions. D) the iron cathode would be corroded by the salt water. E) water is more easily reduced than sodium ions.

E) water is more easily reduced than sodium ions.

Most of the compounds of copper in the __________ oxidation state are insoluble in water. A) +1 B) +2 C) +3 D) +7 E) +6

A) +1

What two oxidation states are more frequently observed in the first transition series than in the third? A) +3 and +7 B) +2 and +3 C) +2 and +7 D) +5 and +6 E) +3 and +5

B) +2 and +3

Roasting ZnS in the presence of oxygen produces the metal oxide and SO₂. What is the coefficient of ZnS when the equation for this reaction is completed and balanced? A) 1 B) 2 C) 3 D) 5 E) 4

B) 2

6.0 karat gold contains __________% gold. A) 6.0 B) 25 C) 5.0x10¹ D) 75 E) 1.0x10²

B) 25

Which one of the following metallic elements is most likely to be found as the free metal in nature? A) Ca B) Au C) Al D) Fe E) Li

B) Au

Transition metals have energy bands composed of two states, low energy and high energy. What elements have filled low energy states and empty high energy states? A) Ti, Zr, Hf B) Cr, Mo, W C) Co, Rh, Ir D) Cu, Ag, Au E) Zn, Cd, Hg

B) Cr, Mo, W

Which one of the following is false concerning the Bayer Process? A) It is a hydrometallurgical process. B) It involves treatment of bauxite with cold, dilute sodium hydroxide solution. C) In the process, aluminum is converted to a soluble aluminate ion. D) It results in the separation of aluminum from iron and silicon. E) It is used to purify bauxite.

B) It involves treatment of bauxite with cold, dilute sodium hydroxide solution.

Which statement below is true? A) New mining techniques and relatively untapped ore fields mean that the environmental impacts of mineral extraction will decrease significantly in the future. B) There exists little correlation between the abundance of an element in the lithosphere and its commercial extraction and use. C) Most metallic elements are found in the lithosphere in oxidation state zero. D) The most important commercial class of minerals is the silicates. E) The United States has plentiful ore fields of all strategic metals.

B) There exists little correlation between the abundance of an element in the lithosphere and its commercial extraction and use.

When carbon monoxide is used to reduce an ore as in a blast furnace, it is converted to __________. A) graphite B) carbon dioxide C) methane D) carbonate E) methanol

B) carbon dioxide

Chalcocite, chalcopyrite, and malachite are sources of which metal? A) manganese B) copper C) titanium D) iron E) zinc

B) copper

What is the typical effect of the addition of an interstitial element on the properties of a metal? A) increase in malleability and corrosion resistance B) increase in hardness and strength, decrease in ductility C) decrease in melting point and increase in ductility D) decrease in conductivity and increase in brittleness E) increased surface luster

B) increase in hardness and strength, decrease in ductility

If the electronic structure of a solid substance consists of a valence band that is completely filled with electrons and there is a large energy gap to the next set of orbitals, then this substance will be a(n) __________. A) alloy B) insulator C) conductor D) semiconductor E) nonmetal

B) insulator

A deposit that contains a metal in economically exploitable quantities is called a(n) __________. A) mineral B) ore C) vein D) comstock E) metal

B) ore

Metallurgical processes that utilize high temperatures are collectively called __________. A) hydrometallurgy B) pyrometallurgy C) electrometallurgy D) alloying E) roasting

B) pyrometallurgy

A thermal process that causes reactions between an ore and the atmosphere of the furnace is called __________. A) calcining B) roasting C) smelting D) slag E) refining

B) roasting

Which of the following are not commonly used as sources of metals? A) oxides B) silicates C) sulfides D) carbonates E) All of the above are commonly used sources of metals.

B) silicates

The oxidation state of copper in Cu₂CO₃O(OH)₂ is __________. A) 0 B) +1 C) +2 D) +4 E) -2

C) +2

Carbon monoxide is commonly used to produce free metals from their oxides. What is the coefficient of carbon monoxide in the balanced equation for the production of cobalt from Co₂O₃? A) 1 B) 2 C) 3 D) 5 E) 4

C) 3

12 karat gold contains __________% gold. A) 12 B) 25 C) 5.0x10¹ D) 75 E) 1.0x10²

C) 5.0x10¹

The transition metals in group __________ have the highest melting points. A) 4B B) 3B C) 6B D) 8B E) 2B

C) 6B

What happens to the silicon that is a contaminant in crude iron in a converter? A) it is converted to the tetrafluoride that bubbles out as a gas. B) It is precipitated as sodium silicate. C) It is converted to silicon dioxide and becomes part of the slag. D) It is precipitated as the carbide. E) It is precipitated as iron silicate.

C) It is converted to silicon dioxide

The lanthanide contraction is responsible for the fact that A) Zr and Y have about the same radius. B) Zr and Nb have similar oxidation states. C) Zr and Hf have about the same radius. D) Zr and Zn have similar oxidation states. E) Zr and Hf have the same oxidation states.

C) Zr and Hf have about the same radius

The molecular-orbital model for Ge shows it to be A) a conductor, because all the lower energy band orbitals are filled and the gap between the lower and higher bands is large. B) an insulator, because all the lower energy band orbitals are filled and the gap between the lower and higher bands is large. C) a semiconductor, because the gap between the filled lower and empty higher energy bands is relatively small. D) a semiconductor, because the gap between the filled lower and empty higher energy bands is large. E) a conductor, because its lower energy band orbitals are only partially filled.

C) a semiconductor, because the gap between the filled lower and empty higher energy bands is relatively small.

The product in the Hall electrometallurgical process is A) copper. B) iron. C) aluminum. D) gold. E) silver.

C) aluminum

In the reduction of iron in a blast furnace, limestone is a source of __________ which reacts with silicates and other components of the ore to form __________. A) coke; carbon monoxide B) hematite; pig iron C) calcium oxide; slag D) magnetite; steel E) calcium; molten iron

C) calcium oxide; slag

Processes used to reduce metal ores or to refine metals that are based on the process of electrolysis are collectively referred to as __________. A) pyrometallurgy B) hydrometallurgy C) electrometallurgy D) calcination E) roasting

C) electrometallurgy

Of the following, which is a bulk property? A) electron configuration B) ionization energy C) melting point D) atomic radius E) atomic number

C) melting point

An alloy is a A) heterogeneous mixture of two metals. B) pure metal. C) metallic material that is composed of two or more elements. D) nonmetal with some properties of a metal. E) a mineral containing two or more metals.

C) metallic material that is composed of two or more elements.

Melting an ore and causing the melt to separate into two or more layers is called __________. A) calcining B) roasting C) smelting D) slag E) alloying

C) smelting

The Hall process is A) the pyrometallurgic process used to produce iron. B) the pyrometallurgic process used to produce aluminum. C) the electrolytic process used to produce aluminum. D) the hydrometallurgic process to produce aluminum. E) the electrolytic process used to produce iron.

C) the electrolytic process used to produce aluminum.

Anhydrous aluminum oxide is dissolved in molten cryolite rather than simply melted because __________ A) the cryolite actually provides the aluminum that is to be reduced. B) the cryolite provides a source of sodium ions. C) the melting point of pure, anhydrous aluminum oxide is too high. D) in pure, molten , the aluminum would be oxidized rather than reduced. E) the cryolite provides the necessary fluoride ions.

C) the melting point of pure, anhydrous aluminum oxide is too high.

What is produced when a carbonate is calcined? A) the free metal and sodium carbonate B) the free metal and sulfur dioxide C) the metal oxide and carbon dioxide D) water and the metal hydride E) the free metal and carbon dioxide

C) the metal oxide and carbon dioxide

A disadvantage to leaching gold with aqueous solutions of cyanide ion is that A) it requires the use of ores with a very high concentration of gold. B) the method does not produce gold of high enough purity. C) the method is a potential environmental hazard. D) sodium cyanide is very expensive. E) it is a complicated process requiring more than two dozen separate steps.

C) the method is a potential environmental hazard.

In the Bayer process, the purpose of lowering the pH after the digested ore has been filtered is __________. A) to precipitate the iron hydroxide B) to precipitate the iron oxide C) to precipitate the aluminum hydroxide D) the dissolve the remaining ore E) to dissolve the remaining impurities

C) to precipitate the aluminum hydroxide

The first step in the production of nickel from its ore, NiS, is to roast it in the presence of oxygen to form the metal oxide and SO₂. What is the coefficient of oxygen when the equation for this reaction is completed and balanced? A) 1 B) 2 C) 3 D) 5 E) 4

C)3

During roasting, the metal reacts with __________. A) oxygen B) carbon monoxide C) sulfur D) the furnace atmosphere E) iron

D) the furnace atmosphere

18 karat gold contains __________% gold. A) 18 B) 25 C) 89 D) 75 E) 1.0x10²

D) 75

Salts of which of the following transition metals are orange? A) Mn²⁺ B) Zn²⁺ C) Ni²⁺ D) Co²⁺ E) Fe²⁺

D) Co²⁺

A slag is formed when a basic metal oxide reacts with molten __________ at high temperatures. A) Fe₂O₃ B) CaO C) CaSiO₃ D) SiO₂ E) CO

D) SiO₂

Why is either pure oxygen or oxygen diluted with argon used in a converter instead of air? A) The carbon dioxide in air will cause the iron to oxidize and form rust. B) The oxygen concentration is too low to function efficiently at removing impurities. C) The carbon monoxide in air reacts with the iron to form a volatile, and toxic, iron carbonyl. D) The nitrogen in air will react with iron to form iron nitride that will make the iron brittle. E) Because it's cheaper.

D) The nitrogen in air will react with iron to form iron nitride that will make the iron brittle.

The metal __________ is extracted from __________ ore by the Bayer process. A) iron; magnetite B) mercury; cinnabar C) tin; casserite D) aluminum; bauxite E) zinc; sphalerite

D) aluminum; bauxite

For a substitutional alloy to form, the two metals combined must have similar A) ionization potential and electron affinity. B) number of valance electrons and electronegativity. C) reduction potential and size. D) atomic radii and chemical bonding properties. E) band gap and reactivity.

D) atomic radii and chemical bonding properties

The anode sludges from copper refining are important sources of what metal(s)? A) gold B) silver C) aluminum D) both A and B E) all of the above

D) both A and B

The process of heating an ore to decompose it and release any volatile products is referred to as __________. A) roasting B) smelting C) refining D) calcination E) alloying

D) calcination

An advantage to leaching gold with aqueous solutions of cyanide ion is that A) the process requires only one step. B) the gold recovered in this way has higher purity than gold recovered in other ways. C) the method can be used to locate underground gold deposits. D) gold can be recovered from very low-grade ores by this method. E) the process is environmentally safe.

D) gold can be recovered from very low-grade ores by this method

The hydrated nickel(II) ion is A) orange. B) blue. C) yellow. D) green. E) colorless.

D) green

Heterogeneous alloys A) do not have uniform composition throughout. B) have properties that depend on composition. C) have properties that depend on the manner in which the melt is solidified. D) have properties that depend on the manner in which the solid is formed. E) All of the above are true.

D) have properties that depend on the manner in which the solid is formed.

Which element is typically not added to steel to modify its properties? A) carbon B) vanadium C) chromium D) nitrogen E) nickel

D) nitrogen

A mixture of oxygen and argon are blown through molten iron that is produced in a blast furnace for the purpose of A) completing the reduction of iron. B) oxidizing the iron before it cools. C) cooling the molten iron. D) removing carbon, sulfur, and other impurities. E) removing other metals.

D) removing carbon, sulfur, and other impurities.

Which mineral contains titanium? A) pyrolusite B) chalcopyrite C) galena D) rutile E) sphalerite

D) rutile

Alloys generally differ from compounds in that A) the former always contain some carbon. B) the former always contain some iron. C) the former always have semiconductor properties. D) the atomic ratios of the constituent elements in the former are not fixed and may vary over a wide range. E) the former never contain a transition element.

D) the atomic ratios of the constituent elements in the former are not fixed and may vary over a wide range