Chapter 9 2 Draw the Lewis structure for CO32- including any valid

55) Draw the Lewis structure for CO32- including any valid resonance structures. Which of the

following statements is TRUE?

A) The CO32- ion contains one C—O single bond and two C=O double bonds.

B) The CO32- ion contains two C—O single bonds and one C=O double bond.

C) The CO32- ion contains three C—O double bonds.

D) The CO32- ion contains two C—O single bonds and one C≡O triple bond.

E) None of the above are true.

56) Which of the following resonance structures for OCN⁻ will contribute most to the correct structure

of OCN⁻?

A) O(2 lone pairs)=C=N (2 lone pairs)

B) O(1 lone pair) ≡C—N(3 lone pairs)

C) O(1 lone pair)=C(2 lp) N(1 lone pair)

D) O(3 lone pairs)—C≡N(with 1 lone pair)

E) They all contribute equally to the correct structure of OCN⁻.

57) Using Lewis structures and formal charge, which of the following ions is most stable?

OCN⁻ ONC⁻ NOC⁻

A) OCN⁻

B) ONC⁻

C) NOC⁻

D) None of these ions are stable according to Lewis theory.

E) All of these compounds are equally stable according to Lewis theory.

58) Draw the Lewis structure for SO42⁻. How many equivalent resonance structures can be drawn?

A) 6

B) 2

C) 4

D) 3

E) 8

59) Draw the best Lewis structure for Cl3⁻. What is the formal charge on the central Cl atom?

A) -1

B) 0

C) +1

D) +2

E) -2

60) Draw the best Lewis structure for the free radical, NO2. What is the formal charge on the N?

A) 0

B) +1

C) -1

D) +2

E) -2

61) Draw the best Lewis structure for CH3-1. What is the formal charge on the C?

A) 0

B) 1

C) -1

D) 2

63) Draw the best Lewis structure for BrO4⁻ and determine the formal charge on bromine.

A) -1

B) +1

C) 0

D) +2

E) +3

64) Identify the compound with atoms that have an incomplete octet.

A) ICl5

B) CO2

C) BF3

D) Cl2

E) CO

65) Which compound has the longest carbon-carbon bond length?

A) CH3CH3

B) CH2CH2

C) HCCH

D) all bond lengths are the same

66) Which compound has the shortest carbon-carbon bond length?

A) CH3CH3

B) CH2CH2

C) HCCH

D) all bond lengths are the same

67) Which compound has the highest carbon-carbon bond strength?

A) CH3CH3

B) CH2CH2

C) HCCH

D) all bond strengths are the same

68) Place the following in order of increasing bond length.

C-F C-S C-Cl

A) C-S < C-Cl < C-F

B) C-Cl < C-F < C-S

C) C-F < C-S < C-Cl

D) C-F < C-Cl < C-S

E) C-S < C-F < C-Cl

69) Place the following in order of decreasing bond length.

H-F H-I H-Br

A) H-F > H-Br > H-I

B) H-I > H-F > H-Br

C) H-I > H-Br > H-F

D) H-Br > H-F > H-I

E) H-F > H-I > H-Br

70) Place the following in order of decreasing XO bond length, where “X” represents the central atom

in each of the following compounds or ions.

SiO32⁻ CO2 CO32⁻

A) CO2 > SiO32⁻ > CO32⁻

B) CO2 > CO32⁻ > SiO32⁻

C) CO32⁻ > CO2 > SiO32⁻

D) CO32⁻ > SiO32⁻ > CO2

E) SiO32⁻ > CO32⁻ > CO2

71) Place the following in order of increasing bond length.

NO2⁻ NO3⁻ NO

A) NO < NO2⁻ < NO3⁻

B) NO2⁻ < NO3⁻ < NO

C) NO3⁻ < NO < NO2⁻

D) NO < NO3⁻ < NO2⁻

E) NO3⁻ < NO2⁻ < NO

72) Rank the following molecules in decreasing bond energy.

Cl2 Br2 F2 I2

A) I2 > Br2 > Cl2 > F2

B) Cl2 > Br2 > F2 > I2

C) I2 > Cl2 > Br2 > F2

D) Cl2 > I2 > F2 > Br2

73) Identify the bond with the highest bond energy.

A) Si=O

B) N=N

C) C=C

D) C=N

E) O=O

74) Which of the following processes are exothermic?

A) Cl2(g) → 2Cl(g)

B) Br(g) + e⁻ → Br⁻(g)

C) Li(s) → Li(g)

D) NaF(s) → Na⁺(g) + F⁻(g)

E) None of the above are exothermic.

75) Which of the following processes are exothermic?

A) the second ionization energy of Mg

B) the sublimation of Li

C) the breaking the bond of I2

D) the formation of NaBr from its constituent elements in their standard state

E) None of the above are exothermic

76) Which of the following processes are endothermic?

A) K⁺(g) + I⁻(g) → KI(s)

B) 2 Br(g) → Br2(g)

C) Ca(s) → Ca(g)

D) 2 Na(s) + O2(g) → Na2O(s)

E) None of the above are endothermic.

77) Which of the following processes are endothermic?

A) the reaction associated with the lattice energy of LiCl.

B) the reaction associated with the ionization energy of potassium.

C) the reaction associated with the heat of formation of CaS.

D) the formation of F2 from its elements in their standard states.

E) None of the above are endothermic.

78) Use the bond energies provided to estimate ΔH°rxn for the reaction below.

PCl3(g) + Cl2(g) → PCl5(l) ΔH°rxn = ?

Bond Bond Energy (kJ/mol)

Cl–Cl 243

P-Cl 331

A) -243 kJ

B) -419 kJ

C) -662 kJ

D) -67 kJ

E) -905 kJ

79) Use the bond energies provided to estimate ΔH°rxn for the reaction below.

2 Br2(l) + C2H2(g) → C2H2Br4(l) ΔH°rxn = ?

Bond Bond Energy (kJ/mol)

Br–Br 193

C≡C 837

C-C 347

C-Br 276

C-H 414

A) +407 kJ

B) -324 kJ

C) -228 kJ

D) +573 kJ

E) -648 kJ

80) Use the bond energies provided to estimate ΔH°rxn for the reaction below.

CH3OH(l) + 2 O2(g) → CO2(g) + 2 H2O(g) ΔH°rxn = ?

Bond Bond Energy (kJ/mol)

C-H 414

C-O 360

C=O 799

O=O 498

O-H 464

A) +473 kJ

B) -91 kJ

C) -486 kJ

D) -392 kJ

E) +206 kJ

81) Use the bond energies provided to estimate ΔH°rxn for the reaction below.

XeF2 + 2 F2 → XeF6 ΔH°rxn = ?

Bond Bond Energy (kJ/mol)

Xe-F 147

F-F 159

A) -429 kJ

B) +159 kJ

C) -660 kJ

D) +176 kJ

E) -270 kJ

82) Use the bond energies provided to estimate ΔH°rxn for the reaction below.

C2H4(g) + H2(g) → C2H6(g) ΔH°rxn = ?

Bond Bond Energy (kJ/mol)

C-C 347

C-H 414

C=C 611

C≡C 837

H-H 436

A) -128 kJ

B) +98 kJ

C) +700 kJ

D) -102 kJ

E) -166 kJ

Algorithmic Questions

1) Identify an ionic bond.

A) Electrons are pooled.

B) Electrons are shared.

C) Electrons are transferred.

D) Protons are gained.

E) Electrons are lost.

2) Identify the compound with ionic bonding.

A) NaBr

B) Na

C) H2O

D) He

E) S

3) Identify the compound with covalent bonding.

A) NaBr

B) Na

C) H2O

D) He

E) S

4) Identify the compound with metallic bonding.

A) NaBr

B) Na

C) H2O

D) He

E) S

5) Identify the substance that conducts electricity.

A) NaCl dissolved in water

B) solid NaCl

C) ethanol

D) solid sugar

E) sugar dissolved in water.

6) Use Lewis theory to determine the chemical formula for the compound formed between Ba and N.

A) BaN

B) Ba3N2

C) BaN2

D) Ba2N

E) Ba2N3

7) Use Lewis theory to determine the chemical formula for the compound formed between Na and O.

A) NaO

B) NaO2

C) Na2O

D) Na2O3

E) Na3O2

8) Use Lewis theory to determine the chemical formula for the compound formed between Ba and I.

A) BaI

B) Ba2I3

C) Ba3I2

D) BaI2

E) Ba2I

9) Use Lewis theory to determine the chemical formula for the compound formed between Al and Cl.

A) Al3Cl2

B) Al2Cl3

C) AlCl2

D) AlCl

E) AlCl3

10) Use Lewis theory to determine the chemical formula for the compound formed between Li and Br.

A) LiBr2

B) Li 2Br

C) Li Br

D) Li 2Br2

11) Which of the following ionic compounds would be expected to have the highest lattice energy?

A) LiF

B) LiCl

C) LiBr

D) LiI

12) Which of the following ionic compounds would be expected to have the highest lattice energy?

A) Li Cl

B) Na Cl

C) K Cl

D) Rb Cl

13) Which ionic compound would be expected to have the highest lattice energy?

A) Rb2O

B) SrO

C) In2O3

D) CO2

14) Identify the compound with the highest magnitude of lattice energy.

A) MgCl2

B) BaCl2

C) SrCl2

D) CsCl2

15) Identify the compound with the lowest magnitude of lattice energy.

A) KCl

B) KBr

C) SrO

D) BaO

16) Place the following in order of increasing magnitude of lattice energy.

MgO LiI BaS

A) BaS < MgO < LiI

B) LiI < BaS < MgO

C) MgO < BaS < LiI

D) LiI < MgO < BaS

E) MgO < LiI < BaS

17) Place the following in order of decreasing magnitude of lattice energy.

KF CaS RbI

A) RbI > KF > CaS

B) RbI > CaS > KF

C) CaS > RbI > KF

D) KF > RbI > CaS

E) CaS > KF > RbI

18) Choose the compound below that should have the highest melting point according to the ionic

bonding model.

A) AlN

B) MgO

C) NaCl

D) CaS

E) RbI