1. University of Kentucky
Clicker Questions
Chapter 9
Chemical Bonding I:
The Lewis Model
Allison Soult
University of Kentucky

2. Which of the following compounds has ionic bonding?
NO2 Al
CaCO3
Answer: e

3. Which of the following compounds has ionic bonding?
NO2 Al
CaCO3
Answer: e

4. Which of the following compounds will have the highest-magnitude lattice energy value?
KBr
NaBr
LiBr
RbBr
All are the same.
Answer: c

5. Which of the following compounds will have the highest-magnitude lattice energy value?
KBr
NaBr
LiBr
RbBr
All are the same.
Answer: c

6. Which of the following represents the lattice energy for AlCl3?
Al(s) + 3/2 Cl2(g)  AlCl3(s)
Al(s)  Al(g)
3/2 Cl2(g)  3 Cl(g)
Al3+(g) + 3 Cl–(g)  AlCl3(s)
Cl(g) + e–  Cl–(g)
Answer: d

7. Which of the following represents the lattice energy for AlCl3?
Al(s) + 3/2 Cl2(g)  AlCl3(s)
Al(s)  Al(g)
3/2 Cl2(g)  3 Cl(g)
Al3+(g) + 3 Cl–(g)  AlCl3(s)
Cl(g) + e–  Cl–(g)
Answer: d

8. Which of the following has the more electronegative atom written first?
Br, Cl
S, F
P, Si
O, S
Answer: d

9. Which of the following has the more electronegative atom written first?
Br, Cl
S, F
P, Si
O, S
Answer: d

10. H─F < H─Br < F─F < Na─Cl F─F < H─F < H─Br < Na─Cl
Rank the following in order of increasing bond polarity: H─F H─Br F─F Na─Cl
H─F < H─Br < F─F < Na─Cl
F─F < H─F < H─Br < Na─Cl
H─Br < H─F < F─F < Na─Cl
F─F < H─Br < H─F < Na─Cl
Na─Cl < H─F < H─Br < F─F
Answer: d

11. H─F < H─Br < F─F < Na─Cl F─F < H─F < H─Br < Na─Cl
Rank the following in order of increasing bond polarity: H─F H─Br F─F Na─Cl
H─F < H─Br < F─F < Na─Cl
F─F < H─F < H─Br < Na─Cl
H─Br < H─F < F─F < Na─Cl
F─F < H─Br < H─F < Na─Cl
Na─Cl < H─F < H─Br < F─F
Answer: d

12. Calculate the percent ionic character of a diatomic molecule with a bond length of 145 pm that has a dipole moment of 5.2 D.
52 %
45 %
75 %
70 %
85 %
Answer: c

13. Calculate the percent ionic character of a diatomic molecule with a bond length of 145 pm that has a dipole moment of 5.2 D.
52 %
45 %
75 %
70 %
85 %
Answer: c

14. Draw the best Lewis structure for XeI2
Draw the best Lewis structure for XeI2. How many lone pairs of electrons are on Xe? 1 2 3 4
Answer: d

15. Draw the best Lewis structure for XeI2
Draw the best Lewis structure for XeI2. How many lone pairs of electrons are on Xe? 1 2 3 4
Answer: d

16. What is the best Lewis structure for CS2?
Answer: d

17. What is the best Lewis structure for CS2?d)
Answer: d

18. Draw the best Lewis structure for NO3–
Draw the best Lewis structure for NO3–. How many equivalent resonance structures can be drawn? 1 2 3 4 5
Answer: c

19. Draw the best Lewis structure for NO3–
Draw the best Lewis structure for NO3–. How many equivalent resonance structures can be drawn? 1 2 3 4 5
Answer: c

20. Determine the formal charge of chlorine in the most stable Lewis structure for ClO2–.–2 –1 +1 +2
Answer: c

21. Determine the formal charge of chlorine in the most stable Lewis structure for ClO2–.–2 –1 +1 +2
Answer: c

22. Which of the following sets gives the correct formal charges for the elements in the Lewis structure below?
S: –2 C: – N: –3
S: +6 C: N: +5
S: +1 C: N: –1
S: 0 C: N: –1
Answer: e

23. Which of the following sets gives the correct formal charges for the elements in the Lewis structure below?
S: –2 C: – N: –3
S: +6 C: N: +5
S: +1 C: N: –1
S: 0 C: N: –1
Answer: e

24. Based on formal charges, which structure of hydrogen cyanide is the most stable?
Answer: b

25. Based on formal charges, which structure of hydrogen cyanide is the most stable?
Answer: b

26. Which of the following has a Lewis structure that is an EXCEPTION to the octet rule?
CO2
ClO2–
I3–
NH3
C2H4
Answer: c

27. Which of the following has a Lewis structure that is an EXCEPTION to the octet rule?
CO2
ClO2–
I3–
NH3
C2H4
Answer: c

28. Phosphorus is the central atom. It contains only single bonds.
Which of the following statements is NOT true about the best Lewis structure for PF5?
Phosphorus is the central atom.
It contains only single bonds.
It violates the octet rule.
There are an odd number of electrons.
All of the statements are true.
Answer: c

29. Phosphorus is the central atom. It contains only single bonds.
Which of the following statements is NOT true about the best Lewis structure for PF5?
Phosphorus is the central atom.
It contains only single bonds.
It violates the octet rule.
There are an odd number of electrons.
All of the statements are true.
Answer: c

30. Using average bond energies, calculate ΔHrxn for the combustion of acetylene.
Bond Energy (kJ/ mol)
C─H
414
C─C
347
C≡C
837
O═O
498
C═O in CO2
799
O─H
464
+1359 kJ
–1359 kJ
+2428 kJ
–2428 kJ
–510 kJ
Answer: d

31. Using average bond energies, calculate ΔHrxn for the combustion of acetylene.
Bond Energy (kJ/ mol)
C─H
414
C─C
347
C≡C
837
O═O
498
C═O in CO2
799
O─H
464
+1359 kJ
–1359 kJ
+2428 kJ
–2428 kJ
–510 kJ
Answer: d

32. Which of the following statements is true of an endothermic reaction?
Strong bonds break and weak bonds form.
Weak bonds break and strong bonds form.
The bonds that break and those that form are of approximately equal strength.
An endothermic reaction does not depend on the bond strength of its components.
Answer: a

33. Which of the following statements is true of an endothermic reaction?
Strong bonds break and weak bonds form.
Weak bonds break and strong bonds form.
The bonds that break and those that form are of approximately equal strength.
An endothermic reaction does not depend on the bond strength of its components.
Answer: a

34. Use average bond energies to determine ΔHrxn for the burning of H2
Use average bond energies to determine ΔHrxn for the burning of H2. H2(g) + ½ O2(g) → H2O(g)
Bond
Bond Energy (kJ/mol)
H─H
436
O═O
498
O─O
142
O─H
464
6 kJ
470 kJ
–243 kJ
–350 kJ
–421 kJ
Answer: c

35. Use average bond energies to determine ΔHrxn for the burning of H2
Use average bond energies to determine ΔHrxn for the burning of H2. H2(g) + ½ O2(g) → H2O(g)
Bond
Bond Energy (kJ/mol)
H─H
436
O═O
498
O─O
142
O─H
464
6 kJ
470 kJ
–243 kJ
–350 kJ
–421 kJ
Answer: c

36. Estimate the enthalpy change for the combustion of methanol, using bond energies.
–3454 kJ
2652 kJ
–1426 kJ
126 kJ
–802 kJ
Answer: e

37. Estimate the enthalpy change for the combustion of methanol, using bond energies.
–3454 kJ
2652 kJ
–1426 kJ
126 kJ
–802 kJ
Answer: e