Chemical Engineering Chapter 14 1 Although the periodic table is organized according to the atomic numbers of the elements, chemists are more interested in the arrangement of the electrons

Chapter 14: Periodic Patterns in the Main Group

Elements: Bonding, Structure, and Reactivity

1. Although the periodic table is organized according to the atomic numbers of the

elements, chemists are more interested in the arrangement of the electrons for their studies.

Which of the following statements about the electron configurations and their quantum numbers

is correct?

A) The size of an atom is associated with the angular momentum quantum number.

B) The valence electrons of atoms in a particular group have the same principal and

angular momentum quantum numbers.

C) The valence electrons of atoms in a particular group have the same angular

momentum quantum number but have different principal quantum numbers.

D) Quantum numbers for the electrons tell us little about the relative energies of the

electrons.

E) None of the above statements is correct.

2. Which of the following statements about the effective nuclear charge, Zeff, is correct?

A) Zeff increases with the size of the atom.

B) Zeff decreases across a period and increases down a group.

C) Zeff increases across a period and is relatively constant down a group.

D) Zeff increases as the value of the principal quantum number increases.

E) Zeff is greater for hydrogen than for any other element.

3. The smallest ionization energies are found in the ____________ ___________ region of

the periodic table.

A) upper right D) lower left

B) upper left E) transition element (d-block)

C) lower right

4. The largest electronegativities are found in the _____________ ____________ region of

the periodic table.

A) upper left D) lower right

B) upper right E) transition element (d-block)

C) lower left

5. Which of the following elements has the lowest electronegativity?

A) Al B) S C) Mg D) In E) Ba

Chapter 14: Periodic Patterns in the Main Group Elements: Bonding, Structure, and Reactivity

6. Bromine will form compounds with each of the other elements in Period 4 of the

periodic table. How does the type of bonding in the compounds change as one moves from

potassium bromide to selenium bromide?

A) ionic to polar covalent D) coordinate covalent to polar covalent

B) polar covalent to ionic E) none of the above

C) polar covalent to non-polar covalent

7. The atomic radius of sodium is 186 pm and of chlorine is 100 pm. The ionic radius for

Na+ is 102 pm and for Cl– is 181 pm. In going from Na to Cl in Period 3, why does the atomic

radius decrease while the ionic radius increases?

A) The inner electrons in the sodium cation shield its valence electrons more

effectively than the inner electrons in the chloride anion do.

B) The inner electrons shield the valence electrons more effectively in the chlorine

atom than in the chloride anion.

C) The outermost electrons in chloride experience a smaller effective nuclear charge

than those in the sodium cation do.

D) The outermost electrons in chloride experience a larger effective nuclear charge

than those in the sodium cation do.

E) Monatomic ions are bigger than the atoms from which they are formed.

8. Select the element with the lowest first ionization energy.

A) Se B) S C) Sn D) Sr E) H

9. Select the element with the highest first ionization energy.

A) Mg B) Ca C) Ba D) Ra E) K

10. Which of the following pairs of elements will form the longest single bond?

A) C, F B) C, N C) C, S D) C, O E) C, H

11. Which of the following ions and atoms has the greatest radius?

A) Se2– B) Br– C) Rb+ D) Sr2+ E) Kr

12. Which of the following atoms has the smallest volume?

A) Ba B) Cs C) Sr D) Rb E) I

Chapter 14: Periodic Patterns in the Main Group Elements: Bonding, Structure, and Reactivity

13. Which of the following oxides will give the most basic solution when dissolved in

water?

A) SO2 B) CO2 C) K2O D) P4O10 E) SO3

14. Which of the following oxides will give the most acidic solution when dissolved in

water?

A) MgO B) Al2O3 C) Cl2O D) SrO E) H2O2

15. Which of the following will have the highest boiling point?

A) O2 B) Cl2 C) Br2 D) I2 E) Xe

16. Which of the following pure substances will not participate in hydrogen bonding?

A) CH3NH2 B) CH3CH2OCH2CH3 C) CH3CH2OH D) HF E) H2O2

17. What are the products of the following reaction of strontium hydride and water?

SrH2(s) + H2O(l) →

A) Sr2+(aq) + H2(g) + O2(g) D) Sr(s) + H3O+(aq)

B) Sr2+(aq) + H2(g) + OH–(aq) E) none of the above

C) Sr(s) + H2(g) + OH–(aq)

18. What are the products of the reaction of potassium hydride and water?

KH(s) + H2O(l) →

A) K(s) + H2(g) + OH–(aq) D) K+(aq) + H2(g) + O2(g)

B) K(s) + H2(g) + O2(g) E) K+(aq) + H2(g) + OH–(aq)

C) KOH(s) + O2(g)

19. Hydrogen forms metallic (interstitial) hydrides with the d and f transition elements.

Which of the following statements is correct?

A) These substances have distinct stoichiometric formulas like ionic hydrides.

B) Hydrogen forms bonds with the metals by donating its electron to the valence band

of the metal.

C) Hydrogen molecules and atoms occupy holes within the crystal structure of the

metal.

D) These substances are useful catalysts.

E) These hydrides are stabilized by hydrogen bonding forces.

Chapter 14: Periodic Patterns in the Main Group Elements: Bonding, Structure, and Reactivity

20. Which one of the following elements is likely to exhibit the most violent and rapid

reaction with water?

A) Na B) Rb C) Mg D) Sr E) Cl2

21. Which of the following substances is produced when lithium metal reacts with oxygen

gas? A) hydrogen gas D) a basic oxide

B) lithium peroxide E) lithium hydroxide

C) an acidic oxide

22. Which of the alkali metals has the highest melting point?

A) Li B) Na C) K D) Rb E) Cs

23. Which one of the following trends occurs as one moves down the group 1A (1) elements

from Li to Cs?

A) metallic character decreases D) first ionization energy increases

B) electronegativity increases E) chemical reactivity increases

C) melting point increases

24. Which of the following bonds should have the greatest ionic character?

A) O–F B) N–F C) C–F D) B–F E) Cl–F

25. Which element forms compounds which are used to treat individuals suffering from

manic-depressive disorders?

A) fluorine B) lithium C) boron D) beryllium E) arsenic

26. Which element forms compounds, e.g., Teflon, which are used as coatings for other

substances?

A) boron B) beryllium C) fluorine D) nitrogen E) sodium

27. Which element forms compounds which are involved in smog and acid rain?

A) carbon B) fluorine C) chlorine D) boron E) nitrogen

Chapter 14: Periodic Patterns in the Main Group Elements: Bonding, Structure, and Reactivity

28. Predict the products for the following set of reactants.

Li(s) + H2O(l) →

A) Li+(aq) + H2(g) + O2(g) D) Li+(aq) + H2O2(aq)

B) Li+(aq) + H2(g) + OH–(aq) E) LiOH(aq) + H2O2(aq)

C) LiH(s) + O2(g)

29. Predict the products for the following set of reactants.

K2O(s) + H2O(l) →

A) K+(aq) + OH–(aq) + H2(g) D) KH(s) + O2(g)

B) K+(aq) + OH–(aq) E) K+(aq) + OH–(aq) + H2O2(aq)

C) K+(aq) + H2(g) + O2(g)

30. Most of the alkali metal salts are soluble in water while many alkaline earth salts have

very low solubilities. Why is this so?

A) The alkali metal cations are smaller than the alkaline earth cations and are more

easily hydrated.

B) The alkali metals have lower ionization energies than alkaline earth elements.

C) The alkaline earth salts have much greater lattice energies than the alkali metal

salts.

D) The alkaline earth metals have greater heats of atomization than the alkali metals.

E) Alkaline earth cations have very low heats of hydration.

31. Unlike the remainder of the Group 1A(1) elements, lithium forms many salts that have

some covalent bond character. What is a reason for this behavior?

A) The high first ionization energy of lithium makes sharing the electron easier than

transferring it.

B) The high charge density on the lithium cation deforms nearby polarizable electron

clouds.

C) The atomic radius of lithium enables it to share its valence electron effectively.

D) Since lithium has only 1 electron in its 2s orbital, it can accept an electron from

another element.

E) Lithium’s electronegativity is more like that of a non-metal than a metal.

32. In which of the following ways is lithium different from the other alkali metals?

A) Its salts are much more soluble in water than those of the other alkali metals.

B) It has an unusually high density.

C) It forms molecular compounds with the hydrocarbon groups of organic halides.

D) Its ionization energy is lower than expected.

E) It does not react with water at room temperature.

Chapter 14: Periodic Patterns in the Main Group Elements: Bonding, Structure, and Reactivity

33. Predict the products for the following set of reactants.

Li(s) + CH3Cl(g) →

A) CH3CH3(g) + LiCl(s) D) CH3Li(s) + Cl2(g)

B) CH4(g) + LiCl(s) E) CH2Li(s) + HCl(g)

C) CH3Li(s) + LiCl(s)

34. The elements from Groups 1A(1) and 2A(2) are

A) strong acids. D) strong oxidizing agents.

B) strong bases. E) strong reducing agents.

C) amphoteric.

35. Predict the products for the reaction of the following set of reactants.

CaO(s) + H2O(l) →

A) Ca2+(aq) + OH–(aq) + H2(g) D) Ca(OH)2(s)

B) Ca2+(aq) + H2(g) + O2(g) E) CaH2(s) + O2(g)

C) Ca2+(aq) + H3O+(aq)

36. Predict the products for the reaction of the following set of reactants.

Sr(s) + H2O(l) →

A) SrO(s) + H2(g) D) Sr(OH)2(s) + H2(g)

B) Sr2+(aq) + H2(g) + O2(g) E) SrH2(s) + O2(g)

C) Sr2+(aq) + H3O+(aq)

37. Predict the products for the reaction of the following set of reactants.

BaO(s) + CO2(g) →

A) BaCO3(s) D) Ba2CO3(s)

B) Ba(s) + CO(g) + O2(g) E) BaC2(s) + O2(g)

C) BaO2(s) + CO(g)

38. Predict the products for the reaction of the following set of reactants.

Mg(s) + Cl2(g) →

A) MgCl(s) B) MgCl2(s) C) MgCl(l) D) MgCl2(l) E) MgCl2(aq)

39. Predict the products for the reaction of the following set of reactants.

MgCO3(s) + heat →

A) Mg(s) + CO(g) D) MgO(s) + CO2(g)

B) Mg(s) + CO2(g) E) no reaction

C) MgO(s) + CO(g)

Chapter 14: Periodic Patterns in the Main Group Elements: Bonding, Structure, and Reactivity

40. Predict the product(s) for the reaction of the following set of reactants.

Ca(s) + H2(g) →

A) CaH(s)

B) CaH2(s)

C) Ca2H3(s)

D) Ca3H2(s)

E) none of the above

41. Magnesium oxide, MgO, is an important industrial material. Which of the following is

one of its uses?

A) antacid D) construction material

B) catalysts E) furnace bricks

C) toothpaste abrasive

42. Thallium can form two oxides, Tl2O and Tl2O3. Which will be the more basic substance?

A) Tl2O

B) Tl2O3

C) They have the same strength as bases.

D) Neither compound has any acidic or basic properties.

E) More information is needed to make an accurate prediction.

43. Which of the following oxides will be the most acidic?

A) Al2O3

B) Ga2O3

C) In2O3

D) Tl2O3

E) None of these oxides is acidic.

44. Which of the following hydroxides will be the most basic?

A) B(OH)3 B) Al(OH)3 C) Ga(OH)3 D) In(OH)3 E) TlOH

45. The most basic oxides contain elements from the ________________ ____________

region of the periodic table.

A) upper right D) lower left

B) upper left E) transition element (d-block)

C) lower right

Chapter 14: Periodic Patterns in the Main Group Elements: Bonding, Structure, and Reactivity

46. The basic character of the binary oxides XmOn

A) is greatest when X has a low atomic number.

B) is greatest when X is a nonmetal.

C) increases as the oxidation number of X increases.

D) increases as the oxidation number of X decreases.

E) is unaffected by the oxidation number of X.

47. Predict the products for the reaction of the following set of reactants.

(CH3)3Ga(g) + AsH3(g) →

A) (CH3)3As(g) + GaH3(g) D) CH4(g) + H2GaAs(s)

B) CH4(g) + GaAs(s) E) CH3H(g) + GaAs(s)

C) CH3CH3(g) + GaAs(s)

48. Boron has 3 valence electrons. Which of the following processes is involved in boron’s

achieving a complete outer shell?

A) formation of a B3+ cation

B) formation of bridge bonds

C) formation of -bonds using its d-orbitals

D) formation of -bonds using sp3-orbitals

E) none of the above

49. Which of the following elements exists in allotropic forms?

A) silicon B) germanium C) tin D) lead E) xenon

50. When elements from a group exhibit more than one oxidation state,

A) the higher oxidation state is more important as one goes down a group.

B) the lower oxidation state is more important as one goes down a group.

C) both oxidation states are equally important throughout the group.

D) the oxidation state will be affected by the elements on either side of it in the

period.

E) None of the above conclusions is true.

51. One important feature of the chemistry of carbon is

A) its large radius that allows other atoms to fit easily around it.

B) its low electronegativity that allows it to ionize easily.

C) its amphoteric behavior.

D) its ability to form multiple bonds with hydrogen.

E) its ability to catenate.

Chapter 14: Periodic Patterns in the Main Group Elements: Bonding, Structure, and Reactivity

52. According to the phase diagram of carbon, what pressure and temperature conditions, if

any, are needed in order for diamond to be the stable phase?

A) low pressure, low temperature

B) low pressure, high temperature

C) high pressure, low temperature

D) high pressure, high temperature

E) Actually, diamond is not stable under any conditions.

53. The polymers containing silicon differ from polymers of carbon in which of the

following ways?

A) Silicon-based polymers are larger molecules than carbon-based polymers.

B) Silicon-based polymers generally have a repeating silicon-oxygen link while

carbon-based polymers can have carbon-carbon links.

C) Silicon-based polymers generally have inorganic elements attached to the chain

while carbon-based polymers generally have organic groups attached.

D) Silicon-based polymers tend to be rigid while carbon-based polymers are generally

flexible.

E) Silicon forms stronger bonds than carbon.

54. Silicon halides have stronger bonds than corresponding carbon halides. Which of the

following is a possible explanation of this phenomenon?

A) The larger silicon atoms permit better overlap of its atomic orbitals with those of

the halogens than the smaller carbons atoms do.

B) The large electronegativity difference between silicon and the halogens makes

their bonds stronger than those of carbon.

C) Silicon has the ability to form a partial double bond with a halogen through the

overlap of its d-orbital with a p-orbital of the halogen.

D) Silicon has a larger effective nuclear charge than carbon which allows it to bond

more strongly to the more negative halogens than carbon.

E) Carbon-halogen bonds are unusually weak.

55. Which of the following pairs of elements exhibit similar physical and chemical

behaviors (“diagonal relationships”)?

A) H and Be B) Na and Be C) Be and Al D) B and Mg E) Li and Al

Chapter 14: Periodic Patterns in the Main Group Elements: Bonding, Structure, and Reactivity

56. Certain Period 2 elements exhibit behaviors similar to Period 3 elements immediately

below and to the right. One of these interesting diagonal relationships occurs between lithium

and magnesium. Which of the following is one of their similarities?

A) They both form insoluble carbonate salts.

B) Both elements are important in treating manic-depression.

C) Their first ionization energies are almost equal.

D) Their densities are very similar.

E) They both form organic compounds with polar covalent bonds from the metal to

hydrocarbon group.

57. Certain Period 2 elements exhibit behaviors similar to Period 3 elements immediately

below and to the right. One of these interesting diagonal relationships occurs between beryllium

and aluminum. Which of the following is one of their differences?

A) Some aluminum compounds and all beryllium compounds show significant

covalent character in the gas phase.

B) Beryllium forms bridge bonds in its hydrides while aluminum does not.

C) Both form oxides that are impervious to reaction with water.

D) The cations for both strongly polarize nearby electron clouds.

E) Beryllium occurs in nature as the uncombined element, whereas aluminum does

not.

58. Certain Period 2 elements exhibit behaviors similar to Period 3 elements immediately

below and to the right. One of the interesting diagonal relationships occurs between boron and

silicon. Which of the following is one of their similarities?

A) Both exhibit electrical properties of a conductor.

B) The oxoanions of both elements occur in extended ionic networks.

C) Both elements form compounds (boranes and silanes) that are good oxidizing

agents.

D) Boric acid and silicic acid occur in layers with widespread hydrogen bonding.

E) Both elements are unusually soft solids.

59. Silicon carbide is an important industrial chemical. Which of the following statements

about silicon carbide is true?

A) It will react with water to form acetylene.

B) It is used in preparation of glass which can be used at high temperature.

C) It is the hardest known substance.

D) It is a naturally occurring mineral source of silicon.

E) It can be doped to form a high temperature semiconductor.

Chapter 14: Periodic Patterns in the Main Group Elements: Bonding, Structure, and Reactivity

60. Tin reacts to form several organic compounds. Which of the following is a use for

organotin compounds?

A) They are starting materials for polymers.

B) They can be used as fungicides.

C) They can be used to prepare semiconductors.

D) They can be used as solvents for reactions involving polar organic compounds.

E) They are used as protective coatings to prevent corrosion of metals.

61. Which of the following oxides is most basic?

A) As2O3 B) P4O10 C) Sb2O3 D) Sb2O5 E) NO2

62. Predict the products for the following set of reactants.

Ca3As2(s) + H2O(l) →

A) As3+(aq) + Ca(OH)2(aq) D) AsH3(g) + Ca(OH)2(aq)

B) As(OH)3(s) + Ca2+(aq) + H2(g) E) CaH2(aq) + As2O3(aq)

C) As(OH)3(s) + Ca(OH)2(aq)

63. Predict the products for the following set of reactants.

PCl3(l) + H2O(l) →

A) H3PO3(aq) + HCl(aq) D) P2O5(s) + HCl(aq)

B) H3PO4(aq) + Cl2(g) E) PCl5(l) + PH3(g) + O2(g)

C) PH3(g) + HCl(aq) + O2(g)

64. Which of the following would you predict to have the greatest thermal stability?

A) AsAt3 B) AsI3 C) AsBr3 D) AsCl3 E) AsF3

65. Dinitrogen monoxide, N2O, is

A) a brown poisonous gas that is one of the chemicals involved in the production of

photochemical smog.

B) a colorless gas used in the production of nitric acid.

C) a colorless gas used as a propellant in canned whipped cream.

D) a colorless gas that disproportionates into nitrogen and oxygen.

E) none of the above.

Chapter 14: Periodic Patterns in the Main Group Elements: Bonding, Structure, and Reactivity

66. Sodium tripolyphosphate is useful

A) as a starting material in the synthesis of organic phosphorus compounds.

B) as a water-softening agent.

C) as an emulsifier in making of processed cheese.

D) as a radiator corrosion inhibitor.

E) as a fertilizer.

67. The nitrate anion is

A) a strong acid. D) a strong reducing agent.

B) a strong base. E) a strong oxidizing agent.

C) amphoteric.

68. Nitric acid, HNO3

A) is a strong reducing agent.

B) is a weak oxidizing agent.

C) does not react with copper metal.

D) may react with copper metal to produce NO gas.

E) reacts with metal hydroxides to produce nitrite salts.

69. Which of the following formulas does not represent a stable compound?

A) N2O B) NO C) NO2 D) NO3 E) N2O4

70. Predict the products for the following set of reactants.

Bi(s) + Cl2(g) →

A) BiCl B) BiCl2 C) BiCl3 D) BiCl4 E) BiCl5

71. Which of the following has the most allotropes?

A) carbon B) sulfur C) oxygen D) selenium E) nitrogen

72. What is the stable form of the element sulfur, at room temperature?

A) atomic sulfur B) S2 C) S4 D) S6 E) S8

Chapter 14: Periodic Patterns in the Main Group Elements: Bonding, Structure, and Reactivity

73. Which of the following is an accurate comparison of the properties of nitrogen and

oxygen?

A) Both oxygen and nitrogen form anions easily.

B) Oxygen is a strong oxidizing agent while nitrogen is a strong reducing agent.

C) Nitrogen uses more oxidation states in its compounds than oxygen does.

D) Nitrogen is more reactive than oxygen.

E) Nitrogen does not form naturally-occurring compounds, but oxygen does.

74. Predict the products formed from the following set of reactants.

FeSe(s) + HCl(aq) →

A) Se(s) + FeCl2(aq) D) H2Se(g) + Fe(s) + Cl2(g)

B) SeCl2(s) + Fe(s) + H2(g) E) H2Se(g) + FeCl2(aq)

C) FeH2(s) + SeCl2(l)

75. Sulfur hexafluoride, SF6, is

A) a reactive gas that decomposes when exposed to moisture.

B) a reactive gas used to fluorinate organic compounds.

C) an inert gas that is used as an electrical insulator.

D) a reactant in the process of manufacturing non-stick coatings.

E) used in the manufacture of sulfuric acid.

76. Hydrogen peroxide, H2O2, is

A) used in the production of polymers.

B) used as a drying agent.

C) colored liquid with a low boiling point.

D) an acid.

E) an explosive.

77. The chemical that ranks first in production among all industrial chemicals is

A) NH3, ammonia. D) Na2CO3, sodium carbonate.

B) H3PO4, phosphoric acid. E) H2SO4, sulfuric acid.

C) NaOH, sodium hydroxide.

78. The halogens are

A) strong oxidizing agents. D) strong bases.

B) strong reducing agents. E) amphoteric.

C) strong acids.

Chapter 14: Periodic Patterns in the Main Group Elements: Bonding, Structure, and Reactivity

79. What is the highest oxidation state of chlorine in any of its compounds?

A) -1 B) 0 C) +1 D) +3 E) +7

80. The strongest elemental oxidizing agents are found in the _________ _________ region

of the periodic table while the strongest reducing agents are found in the ________ ________

region of the periodic table.

A) upper left, lower right D) lower right, upper left

B) upper right, lower left E) transition element, main group

C) lower left, upper right

81. Predict the products for the following set of reactants.

Cs(s) + Br2(l) →

A) CsBr(s) B) CsBr2(s) C) CsBr(l) D) CsBr2(l) E) Cs2Br(s)

82. Predict the products for the following set of reactants.

Cl2(g) + I–(aq) →

A) ICl B) ICl2 C) ICl3 D) I2 + Cl– E) I + Cl2–

83. Which of the following is the strongest acid?

A) HClO3 B) HBrO3 C) HIO3 D) HIO2 E) HClO

84. Predict the products for the following set of reactants.

H2O(l) + ClF5(l) →

A) HClO2(aq) + HF(aq) D) HCl(aq) + HF(aq)

B) HClO3(aq) + HF(aq) E) HClO(aq) + HFO(aq)

C) HClO(aq) + HF(aq)

85. Sodium hypochlorite is used

A) in chemical analysis. D) in the manufacture of steel.

B) as an oxidizer in rocket fuels. E) as a detergent.

C) as a disinfectant.

Chapter 14: Periodic Patterns in the Main Group Elements: Bonding, Structure, and Reactivity

Page 225

86. Hydrogen fluoride is used

A) in the manufacture of steel.

B) in the synthesis of cryolite for aluminum production.

C) as an oxidizing agent.

D) as a disinfectant.

E) as a mouthwash.

87. Which, if any, of the following generalized formulas does not exist for interhalogen

compounds? (X and Y represent different halogens.)

A) XY

B) XY2

C) XY3

D) XY5

E) All the above can represent stable interhalogen compounds.

88. Xenon forms several compounds with oxygen and fluorine. It is the most reactive non-

radioactive noble gas because

A) its large radius allows oxygen and fluorine to bond without being crowded.

B) it has the highest electronegativity of these noble gases.

C) it has the highest electron affinity of these noble gases.

D) its effective nuclear charge is lower than the other noble gases.

E) it has the lowest ionization energy of these noble gases.

89. Predict the molecular shape of XeF3–.

A) linear

B) trigonal planar

C) trigonal pyramid

D) T-shaped

E) square

90. Name the three different classes (types) of hydride, and list some of their important

characteristics.

Chapter 14: Periodic Patterns in the Main Group Elements: Bonding, Structure, and Reactivity

91. If an alkali metal is represented by the symbol M, what is the formula of

a. the oxide of M?

b. the peroxide of M?

c. the superoxide of M?

92. Name the three allotropes of carbon and briefly describe their properties and structures.

93. Write balanced equations, showing all reactants and products, to represent

a. the reaction of calcium metal with water.

b. the reaction of aluminum metal with oxygen gas.

94. Write balanced equations, showing all reactants and products, to represent

a. the reaction of lithium metal with oxygen to form lithium oxide.

b. the formation of ammonia in the Haber process.

95. Write balanced equations, showing all reactants and products, to represent

a. roasting of limestone (CaCO3) to give lime.

b. tetraphosphorus decaoxide (P4O10) reacting with water to produce phosphoric acid.

Chapter 14: Periodic Patterns in the Main Group Elements: Bonding, Structure, and Reactivity

96. Consider the oxides XO2, where X is a main-group element. Identify X in each of the

following cases:

a. XO2 is a natural component of the atmosphere, implicated in global warming.

b. XO2 is a toxic, brown gas and a component of photochemical smog.

c. XO2 is a colorless, toxic gas, implicated in acid rain.

d. XO2 is network solid; one form of it is the mineral quartz.

97. Identify by number (1A-8A) the main-group of the periodic table to which the described

element (X) belongs, in each of the following cases.

a. X commonly forms the ion X2–.

b. X reacts with water according to the equation

X(s) + 2H2O(l) → X(OH)2(aq) + H2(g)

c. X exists as molecules, X2; its hydride has the formula HX.

d. X is a metal which reacts with oxygen to produce the peroxide, X2O2.

98. Each one of the following statements applies to an element or elements from one of the

main groups (1A through 8A). Identify the group number appropriate to each of the statements,

and write it in the left hand margin alongside that statement.

a. This group contains the element with the lowest ionization potential of any element.

b. The maximum oxidation number of any element in this group is +5.

c. An element X in this group forms a stable, unreactive gas, XF6.

99. Ionic hydrides do not have exact (stoichiometric) formulas.

100. The acidity of oxides of main group elements increases across a period from left to right.

101. The acidity of oxides of main group elements increases down a group, from top to

bottom.

Chapter 14: Periodic Patterns in the Main Group Elements: Bonding, Structure, and Reactivity

102. Potassium is a strong reducing agent.

103. Potassium nitrate is a strong reducing agent.

104. In gaseous BeCl2, Be does not obey the octet rule; in solid BeCl2 it does.

105. In the gas phase, AlCl3 exists as molecules of Al2Cl6.

106. Group 1A elements are less reactive than group 2A elements.

107. Salts of group 1A metals are generally more soluble than those of group 2A metals.

108. Oxides of group 1A (1) and 2A (2) elements are strongly acidic.

109. Elements of group 1A have higher melting and boiling points than those of group 2A.

110. Carbon monoxide’s toxicity is related to its ability to bond to iron in hemoglobin.

111. The Haber process is the first step in the manufacture of sulfuric acid.

112. Phosphoric acid (H3PO4) is a strong acid.

113. Sulfur hexafluoride is a pollutant responsible for acid rain.

114. Oxygen gas (O2) is paramagnetic, but ozone (O3) is diamagnetic.

115. Ozone is both a pollutant and a natural component of the atmosphere.

116. Sulfuric acid is produced when sulfur dioxide dissolves in water.

Chapter 14: Periodic Patterns in the Main Group Elements: Bonding, Structure, and Reactivity

117. The halogens act as oxidizing agents in most of their reactions.

118. Neon does not form any known compounds.