Question 1

The electronic structure of which of the following species cannot be adequately described by a single Lewis formula?

Accepted Answer

A) CS2 
B) POF3 
C) HNNH 
D) NO3- 
E) H2NNH2 
A) CS2 
B) POF3 
C) HNNH 
D) NO3- 
E) H2NNH2

Question 2

How many valence electrons are present in the Lewis formula for the chlorate ion,C1O3-?

Accepted Answer

A) 32 
B) 24 
C) 30 
D) 26 
E) 28 
A) 32 
B) 24 
C) 30 
D) 26 
E) 28

Question 3

Which of the following covalent molecules does not have the proper Lewis dot formula?

Accepted Answer

A)    
B)    
C)    
D)    
E)    
A)    
B)    
C)    
D)    
E)

Question 4

In the Lewis dot formula for ICl2-,the number of lone pairs of electrons around the central iodine atom is

Accepted Answer

A) 2. 
B) 4. 
C) 1. 
D) 3. 
E) 0. 
A) 2. 
B) 4. 
C) 1. 
D) 3. 
E) 0.

Question 5

Which of the following compounds would be expected to have the highest melting point?

Accepted Answer

A) CsF 
B) LiCl 
C) LiF 
D) NaBr 
E) CsI 
A) CsF 
B) LiCl 
C) LiF 
D) NaBr 
E) CsI

Question 6

Which of the following molecules has an incorrect Lewis formula?

Accepted Answer

A)    
B)    
C)    
D)    
E)    
A)    
B)    
C)    
D)    
E)

Question 7

From a consideration of the Lewis structure of the thiocyanate ion,SCN-,in which carbon has a double bond with both the sulfur and nitrogen atoms,the formal charges on the sulfur,carbon,and nitrogen atoms are,respectively,

Accepted Answer

A) -1,+1,-1. 
B) -2,0,+1. 
C) -1,0,0. 
D) -2,+1,0. 
E) 0,0,-1. 
A) -1,+1,-1. 
B) -2,0,+1. 
C) -1,0,0. 
D) -2,+1,0. 
E) 0,0,-1.

Question 8

All of the following species are isoelectronic except

Accepted Answer

A) Ar. 
B) Ca2+. 
C) Mg2+. 
D) Cl-. 
E) S2-. 
A) Ar. 
B) Ca2+. 
C) Mg2+. 
D) Cl-. 
E) S2-.

Question 9

Which species has the largest number of lone pairs of electrons around the central atom?

Accepted Answer

A) XeF2 
B) XeF6 
C) XeOF4 
D) XeF4 
E) SiF62- 
A) XeF2 
B) XeF6 
C) XeOF4 
D) XeF4 
E) SiF62-

Question 10

All of the following species have ground-state noble-gas electron configurations except

Accepted Answer

A) Ge4+ 
B) K+ 
C) Kr 
D) I- 
E) P3- 
A) Ge4+ 
B) K+ 
C) Kr 
D) I- 
E) P3-

Question 11

Which of the following diatomic species do you expect to have the longest bond length?

Accepted Answer

A) O2+ 
B) O22- 
C) O2 
D) O2- 
E) they are all identical 
A) O2+ 
B) O22- 
C) O2 
D) O2- 
E) they are all identical

Question 12

Rank the following ions in order of decreasing ionic radius: S2-,O2-,F-,Na+,Mg2+.

Accepted Answer

A) S2-,O2-,F-,Na+,Mg2+ 
B) O2-,F-,Na+,Mg2+,S2- 
C) O2-,S2-,F-,Na+,Mg2+ 
D) Mg2+,Na+,F-,O2-,S2- 
E) Mg2+,S2-,Na+,F-,O2- 
A) S2-,O2-,F-,Na+,Mg2+ 
B) O2-,F-,Na+,Mg2+,S2- 
C) O2-,S2-,F-,Na+,Mg2+ 
D) Mg2+,Na+,F-,O2-,S2- 
E) Mg2+,S2-,Na+,F-,O2-

Question 13

Which of the following is the Lewis dot structure for one formula unit of calcium sulfide?

Accepted Answer

A)    
B) ​   
C) ​   
D) ​   
E) ​   
A)    
B) ​   
C) ​   
D) ​   
E) ​

Question 14

Which set of ions are isoelectronic in their ground-state electron configurations?

Accepted Answer

A) N,O,F,Ne 
B) Na+,K+,Rb+,Cs+ 
C) F-,Cl-,Br-,I- 
D) Mg2+,Ca2+,Sr2+,Ba2+ 
E) N3-,O2-,Mg2+,Al3+ 
A) N,O,F,Ne 
B) Na+,K+,Rb+,Cs+ 
C) F-,Cl-,Br-,I- 
D) Mg2+,Ca2+,Sr2+,Ba2+ 
E) N3-,O2-,Mg2+,Al3+

Question 15

Which two species are isoelectronic?

Accepted Answer

A) Na+ and K+ 
B) Al3+ and Ne 
C) P- and Ca+ 
D) Cl- and F- 
E) Ca2+ and Mg2+ 
A) Na+ and K+ 
B) Al3+ and Ne 
C) P- and Ca+ 
D) Cl- and F- 
E) Ca2+ and Mg2+

Question 16

All of the following ions have the ground-state electron configuration of a noble gas except which one?

Accepted Answer

A) Ca2+ 
B) Cl- 
C) Ga3+ 
D) Al3+ 
E) H- 
A) Ca2+ 
B) Cl- 
C) Ga3+ 
D) Al3+ 
E) H-

Question 17

The octet rule is violated by at least one atom in all the following compounds except

Accepted Answer

A) SiF5-. 
B) SCl6. 
C) BrF5. 
D) SiF62-. 
E) NF3. 
A) SiF5-. 
B) SCl6. 
C) BrF5. 
D) SiF62-. 
E) NF3.

Question 18

All the following statements about resonance are true except

Accepted Answer

A) A single Lewis formula does not provide an adequate representation of the bonding. 
B) Resonance describes a more stable situation than does any one contributing resonance formula. 
C) Resonance describes the oscillation and vibration of electrons. 
D) The contributing resonance formulas differ only in the arrangement of the electrons. 
E) Resonance describes the bonding as intermediate between the contributing resonance formulas. 
A) A single Lewis formula does not provide an adequate representation of the bonding. 
B) Resonance describes a more stable situation than does any one contributing resonance formula. 
C) Resonance describes the oscillation and vibration of electrons. 
D) The contributing resonance formulas differ only in the arrangement of the electrons. 
E) Resonance describes the bonding as intermediate between the contributing resonance formulas.

Question 19

Based on the following data,what is the bond energy of the C=C bond in 1,1-difluoroethylene,CF2CH2?
CH4(g)→ C(g)+ 4H(g); ΔH = 1656 kJ
CF4(g)→ C(g)+ 4F(g); ΔH = 1756 kJ
CF2CH2(g)→ 2C(g)+ 2H(g)+ 2F(g); ΔH = 2317 kJ

Accepted Answer

A) 611 kJ/mol 
B) 845 kJ/mol 
C) 820 kJ/mol 
D) 1706 kJ/mol 
E) 1910 kJ/mol 
A) 611 kJ/mol 
B) 845 kJ/mol 
C) 820 kJ/mol 
D) 1706 kJ/mol 
E) 1910 kJ/mol

Question 20

How is a covalent bond formed?

Accepted Answer

A) By the sharing of valence protons between atoms 
B) By the sharing of positrons between atoms 
C) ​By the sharing of a pair of electrons between atoms 
D) ​By the sharing of boson particles between atoms 
E) ​By the sharing of a pair of neutrons between atoms 
A) By the sharing of valence protons between atoms 
B) By the sharing of positrons between atoms 
C) ​By the sharing of a pair of electrons between atoms 
D) ​By the sharing of boson particles between atoms 
E) ​By the sharing of a pair of neutrons between atoms

Exam 9: Ionic and Covalent Bonding

The electronic structure of which of the following species cannot be adequately described by a single Lewis formula?

How many valence electrons are present in the Lewis formula for the chlorate ion,C1O3-?

Which of the following covalent molecules does not have the proper Lewis dot formula?

In the Lewis dot formula for ICl2-,the number of lone pairs of electrons around the central iodine atom is

Which of the following compounds would be expected to have the highest melting point?

Which of the following molecules has an incorrect Lewis formula?

From a consideration of the Lewis structure of the thiocyanate ion,SCN-,in which carbon has a double bond with both the sulfur and nitrogen atoms,the formal charges on the sulfur,carbon,and nitrogen atoms are,respectively,

All of the following species are isoelectronic except

Which species has the largest number of lone pairs of electrons around the central atom?

All of the following species have ground-state noble-gas electron configurations except

Which of the following diatomic species do you expect to have the longest bond length?

Rank the following ions in order of decreasing ionic radius: S2-,O2-,F-,Na+,Mg2+.

Which of the following is the Lewis dot structure for one formula unit of calcium sulfide?

Which set of ions are isoelectronic in their ground-state electron configurations?

Which two species are isoelectronic?

All of the following ions have the ground-state electron configuration of a noble gas except which one?

The octet rule is violated by at least one atom in all the following compounds except

All the following statements about resonance are true except

Based on the following data,what is the bond energy of the C=C bond in 1,1-difluoroethylene,CF2CH2? CH4(g)→ C(g)+ 4H(g); ΔH = 1656 kJ CF4(g)→ C(g)+ 4F(g); ΔH = 1756 kJ CF2CH2(g)→ 2C(g)+ 2H(g)+ 2F(g); ΔH = 2317 kJ

How is a covalent bond formed?

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Filters

How many valence electrons are present in the Lewis formula for the chlorate ion,C1O₃^-?

In the Lewis dot formula for ICl₂^-,the number of lone pairs of electrons around the central iodine atom is

From a consideration of the Lewis structure of the thiocyanate ion,SCN^-,in which carbon has a double bond with both the sulfur and nitrogen atoms,the formal charges on the sulfur,carbon,and nitrogen atoms are,respectively,

Rank the following ions in order of decreasing ionic radius: S^2-,O^2-,F^-,Na⁺,Mg²⁺.

Based on the following data,what is the bond energy of the C=C bond in 1,1-difluoroethylene,CF₂CH₂? CH₄(g)→ C(g)+ 4H(g); ΔH = 1656 kJ CF₄(g)→ C(g)+ 4F(g); ΔH = 1756 kJ CF₂CH₂(g)→ 2C(g)+ 2H(g)+ 2F(g); ΔH = 2317 kJ