University of New England CHEM 1020 Chapter 1 -- Bonding and Isomerism MULTIPLE CHOICE 1)What is the most electropositive element? Li Be B C N                                              Which of the following elements has three electrons in the valence (outer) shell? C B S F N                                              Which of the following would you expect to have ionic bonds? HBr CO ICl CsF NF3                                              Which of the following would you expect to have polar covalent bonds? MgF2 N2 F2 NF3 NaF                                              Which molecule has nonpolar covalent bonds? NO N2 BCl3 HF CCl4                                              The number of electrons in the valence shell of sulfur is: 2   3 4 5 6                                              Which of the following elements is the most electronegative? O S Se Te Po                                              If the Cl–Cl bond length is 1

University of New England

CHEM 1020

Chapter 1 -- Bonding and Isomerism

MULTIPLE CHOICE

1)What is the most electropositive element?

1. 1. Li
   2. Be
   3. B
   4. C
   5. N

2. Which of the following elements has three electrons in the valence (outer) shell?
   1. C
   2. B
   3. S
   4. F
   5. N

3. Which of the following would you expect to have ionic bonds?
   1. HBr
   2. CO
   3. ICl
   4. CsF
   5. NF₃

4. Which of the following would you expect to have polar covalent bonds?
   1. MgF₂
   2. N₂
   3. F₂
   4. NF₃
   5. NaF

5. Which molecule has nonpolar covalent bonds?
   1. NO
   2. N₂
   3. BCl₃
   4. HF
   5. CCl₄

6. The number of electrons in the valence shell of sulfur is:
   1. 2

1. 2. 3
   3. 4
   4. 5
   5. 6

7. Which of the following elements is the most electronegative?
   1. O
   2. S
   3. Se
   4. Te
   5. Po

8. If the Cl–Cl bond length is 1.98Å and the C–C bond length is 1.54Å, what would you expect the bond length of Cl–C to be?

A) 0.74Å

B) 1.54Å

C) 1.76Å

D) 1.98Å

E)   3.52Å

9. Given the following electronegativity values, predict the most polar covalent bond below:

1. 1. –F
   2. C–Cl
   3. C–O
   4. C–H
   5. C–C

10. The most electronegative elements in the periodic table are generally found
    1. toward the left in a horizontal row and toward the top in a column.
    2. toward the right in a horizontal row and toward the top in a column.
    3. toward the left in a horizontal row and toward the bottom in a column.
    4. toward the right in a horizontal row and toward the bottom in a column.
    5. distributed randomly throughout the table.

11. Which of the following Lewis Structures for ozone (O₃) is incorrect?

4. structures (A) and (B) are incorrect
5. none of the above structures are incorrect

12. Which of the following molecules are structural isomers?

1. 1. 1, 2, and 4
   2. 1, 2, and 3
   3. 1, 3, and 4
   4. 2, 3, and 4
   5. 3 and 4

13. Which of the following abbreviated structural formulas is NOT an isomer of the others?

14. The number of possible acyclic hydrocarbons with the molecular formula C₄H₆ is

1. 1. 2
   2. 3
   3. 4
   4. 5
   5. 6

15. Which of the following structural formulas represents a structural isomer of CH₃CH₂CH₂CH₂CH₃?

C)     

16. 
    Which of the following molecules are structural isomers?

1. 1. 1, 2 and 3
   2. 1, 3 and 4
   3. 2, 3 and 5
   4. 1, 3 and 5
   5. 2 and 3

17. Which of the following abbreviated structural formulas represents a structural isomer of CH₃CH₂CH₂CH₂CH₃?

B)

18. The structural formula for (CH₃)₂C(CH₂CH₃)₂ is

B)     

D)

19. The structural formula                                     has the molecular formula:

1. 1. C₇H₁₆
   2. C₆H₁₄
   3. C₇H₁₄
   4. C₆H₁₂
   5. C₇H₁₀

20. Which of the following structural formulas does not have the molecular formula C₆H₁₄?

21. Which of the following structural formulas has the molecular formula C₆H₁₂?

1. 1. 2 and 3
   2. 1 and 4
   3. 1, 4, and 5
   4. 1 and 2
   5. 4 and 5

22. The structural formula for (CH₃CH₂)₂CHCH₂CH(CH₃)₂ is

E)

23. The structural formula                                     has the molecular formula:

1. 1. C7H16
   2. C6H14
   3. C7H14
   4. C6H12
   5. C7H10

24. The structural formula                                                                          has the molecular formula:

1. 1. C10H16
   2. C9H16
   3. C11H22
   4. C9H14
   5. C10H18

25. 

    For carbon monoxide,                  , C has a formal charge of:

A) +1

2. –1
3. 0
4. –2

E) +2

26. 

    For carbon monoxide,                  , O has a formal charge of:

A) +1

2. –1
3. 0
4. –2

E) +2

27. 
    What is the formal charge of N in HNO₃, as seen below?

A) +1

B) +2

3. 0
4. –1
5. –2

28. The formal charges in the perchlorate ion are:

1. 1. –1 on each O and +3 on the Cl.
   2. 0 on each O and –1 on the Cl.
   3. –1 on each O and +4 on the Cl.
   4. –1/4 on each O and 0 on the Cl.

E) +1 on each O and –1 on the Cl.

29. Which of the following structures is a resonance structure of                                               :

D)

30. The formal charges in the complex                                         are:

1. 1. 0 on each H, +1 on N, and –1 on B.

B) +1 on each H, +1 on N, and –1 on B.

3. 0 on each H, –1 on N, and +1 on B.
4. 0 on each H, 0 on N, and 0 on B.
5. –1 on each H, +3 on N, and +3 on B.

31. The curved arrows in the resonance structure for the acetate ion shown below indicate the following alternative resonance structure for the acetate ion:

1. 1. 

      

      D)

1. 2. 

      E)

32. What is the percent s character in an sp² hybridized orbital?

A) 25%

B) 33%

C) 50%

D) 67%

E)   75%

33. The maximum number of electrons that a molecular orbital can contain is:
    1. 1
    2. 2
    3. 3
    4. 4
    5. 5

34. The approximate H–C–H bond angle in methane is:

A) 60°

B) 90°

C) 109.5°

D) 120°

E)   180°

35. The Lewis structure of methane is

The shape of the methane can be described as a

1. 1. square planar
   2. trigonal planar
   3. trigonal pyramidal
   4. tetrahedral
   5. square pyramidal

36. Which of the following molecules can be classified as an amide?

A)

B)

E) Answers A and D

37. Which of the following molecules contain the same functional group?

1. 1. 1, 2 and 3
   2. 1, 3 and 4
   3. 1 and 2
   4. 2 and 4
   5. 3 and 4

38. Which of the following molecules is acyclic?