Q&A Hero

Q: Which process is used in the fabrication of ceramics? A) electrolysis B) reduction C) roasting D) sintering

Q: 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.

Q: 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

Q: What structural features appear necessary for superconductivity in the 1-2-3 YBa2Cu3O7 superconductor? 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 these are necessary.

Q: What is the Meissner effect associated with superconductors? It is ________. 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

Q: Below the superconducting transition temperature Tc, superconductors ________. A) become perfect conductors B) become perfect magnets C) become perfect resistors D) fail to work

Q: 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

Q: Who discovered the phenomenon of superconductivity in 1911? A) J. G. Bednorz B) R. B. Fuller C) K. A. Mller D) H. K. Onnes

Q: 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

Q: 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

Q: 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

Q: 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

Q: 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

Q: 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

Q: 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

Q: 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

Q: How would one classify a silicon crystal doped with indium? A) conductor B) n-type semiconductor C) p-type semiconductor D) insulator

Q: How would one classify copper mixed with tin? A) conductor B) n-type semiconductor C) p-type semiconductor D) insulator

Q: How would one classify a germanium crystal doped with arsenic? A) conductor B) n-type semiconductor C) p-type semiconductor D) insulator

Q: Which element has the smallest energy band gap? A) C (diamond) B) Ge C) Pb D) Si

Q: Which element has the largest energy band gap? A) C (diamond) B) Si C) Ge D) Sn (white)

Q: Which substance has a larger band gap than silicon? A) diamond B) copper C) germanium D) silver

Q: Which substance is a good semiconductor? A) diamond B) germanium C) gold D) phosphorus

Q: Which one of the following is an electrical insulator? A) alumina B) germanium doped with antimony C) gold D) tellurium

Q: Which of the following is a semiconductor? A) Al B) B C) Ga D) Pb

Q: 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

Q: 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

Q: Electrical resistance of a metal ________ with increasing temperature. A) can decrease or increase B) decreases C) does not change D) increases

Q: According to band theory, which of the following metals is expected to have the strongest bonding and highest melting point? A) Cs B) Cu C) Rb D) Ru

Q: According to band theory, which one of the following metals is expected to have the highest melting point? A) Cd B) Cr C) Hg D) Zn

Q: Which substance is the best conductor of electricity? A) diamond B) germanium C) gold D) phosphorus

Q: 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

Q: 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

Q: 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 Fe2O3(s) + 3 CO(g) -> 2 Fe(l) + 3 CO2(g).A) 14,300 metric tonsB) 20,000 metric tonsC) 20,400 metric tonsD) 30,000 metric tons

Q: 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, acidicB) acidic, basicC) basic, acidicD) basic, basic

Q: What is not a major component of slag? A) CaSiO3 B) Ca3(PO4)2 C) Fe2O3 D) MnSiO3

Q: 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

Q: 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

Q: 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 and phosphates from the iron ore D) to remove unreactive carbon from the iron ore

Q: Steel is a mixture composed primarily of ________. A) iron and carbon B) iron and copper C) iron and silicon D) iron and sulfur

Q: 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

Q: What conditions favor the decomposition of Ni(CO)4 into Ni and CO after equilibrium is established in the reaction Ni(s) + 4 CO(g) ⇌ Ni(CO)4(g) 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

Q: 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

Q: 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

Q: Which element is likely to be a principal impurity in zinc ore? A) cadmium B) copper C) gallium D) nickel

Q: Which of the following metals is not commonly obtained by electrolysis? A) Al B) Li C) Na D) Zn

Q: 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

Q: 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)

Q: When zinc sulfide undergoes roasting, the products are A) Zn and S B) Zn and H2S C) ZnO and S D) ZnO and SO2

Q: 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

Q: 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 processB) bayer processC) contact processD) mond process

Q: How is slag separated from molten ore in a blast furnace? A) chemical treatment B) density differences C) distillation D) magnetic differences

Q: 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

Q: 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

Q: 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

Q: Vanadium ore contains two isotopes of vanadium, 50V and 51V. The least abundant isotope is radioactive and undergoes beta capture. What is the product of the beta decay? A) 50Cr B) 51Cr C) 50Ti D) 51Ti

Q: Limnite is an ore having a formula that is sometimes written as an iron(III) oxide hydrate, Fe2O3xH2O. If 1.00 kg of limnite produces 0.747 kg of anhydrous Fe2O3 upon heating, what is the number of waters of hydration x in the Fe2O3xH2O? A) 1 B) 2 C) 3 D) 4

Q: Which oxide ore will yield the greatest number of grams of pure metal per kilogram of ore? A) cassiterite, SnO2 B) hematite, Fe2O3 C) pyrolusite, MnO2 D) rutile, TiO2

Q: Which of the following elements is most likely to naturally occur as a carbonate? A) Ca B) Co C) Cr D) Cu

Q: Which of the following elements is most likely to occur as a metal sulfide ore? A) Hf B) Hg C) K D) W

Q: Which metal is not found in nature in uncombined form? A) Ag B) Au C) Pd D) Pt

Q: Which substance is commonly found in nature in an uncombined form? A) aluminum B) iron C) platinum D) tin

Q: The number of unpaired electrons in tetrahedral NiBr42- is ________.

Q: The number of unpaired electrons in square planar PtCl42- is ________.

Q: The number of unpaired electrons in Co(NH3)63+ is ________.

Q: Platinum uses ________ hybrid orbitals to accept electron pairs from ligands in cis-Pt(NH3)2Cl2.

Q: The color exhibited by coordination compounds is usually due to the absorption of light by a d-electron, resulting in the promotion of the d-electron from its ground-state d-orbital to a higher energy orbital. The first transition series element expected to have a colorless aqueous solution M2+ ion is ________.

Q: [Co(NH3)5NCS]2+ and [Co(NH3)5SCN]2+ are examples of ________ isomers.

Q: The number of diastereoisomers possible for [Co(en)2Cl2]+ is ________.

Q: The formula for tetraamminedichlorochromium(III) chloride is ________.

Q: Polydentate ligands are known as ________ agents.

Q: The oxidation state of palladium in K2[PdCl4] is ________.

Q: The coordination number of chromium in [Cr(EDTA)]- is ________.

Q: The coordination number of cobalt in [Co(NH3)4Cl2]Cl is ________.

Q: The coordination number of platinum in Pt(NH3)2Cl2 is ________.

Q: The highest oxidation state attainable by Mn is ________.

Q: The oxidation state of chromium in Cr2O72- is ________.

Q: The first transition series element expected to have the lowest second ionization energy is ________.

Q: The small sizes of third transition series atoms is referred to as the ________ contraction.

Q: The short hand electron configuration of iron in [FeF6]3- is ________.