Test Bank for Fundamentals of General Organic and ... · Test Bank for Fundamentals of General Organic and Biological Chemistry 7th Edition by McMurry Sample Chapter 4 Molecular Compounds

Test Bank for Fundamentals of General Organic and Biological

Chemistry 7th Edition by McMurry

Sample

Chapter 4 Molecular Compounds

Diff: 2 1

Section: 4.1 1

1. A) atomic

2. B) covalent

3. C) hydrogen

4. D) ionic

5. E) molecular

2) A chemical bond formed when two atoms share two pairs of electrons is a ________ bond; it is best described as ________.

1. A) double; covalent

2. B) double; ionic

3. C) single; covalent

4. D) single; ionic

5. E) triple; covalent

Answer: A

Diff: 2

Section: 4.1

3) Which representation of a hydrogen molecule is not correct?

1. A) H=H

2. B) H2

3. C) H:H

4.

5. E) none of the above

Answer: A

Diff: 1

Section: 4.2

4) Which representation of a methane molecule is not correct? (A methane molecule is composed of one carbon atom and four hydrogen atoms.)

1. A) CH4

2. B)

1. C)

1. D)


Answer: D

Diff: 1

Section: 4.2

5) Which element is most likely to form three covalent bonds?

1. A) C

2. B) Si

3. C) P

4. D) S

5. E) Se

Answer: C

Diff: 1

Section: 4.2

6) In a covalent compound the bond length can be defined as

1. A) the distance between any two pairs of electrons.

2. B) the distance between the two largest atoms.

3. C) the distance between two nuclei when the repulsion is greatest.

4. D) the distance between two nuclei when the attraction is greatest.

5. E) the distance between two nuclei when repulsion and attraction are balanced.

Answer: E

Diff: 2

Section: 4.2

7) Which group contains only elements which normally exist as diatomic molecules?

1. A) nitrogen; sulfur, bromine

2. B) helium; neon, argon

3. C) nitrogen; oxygen, fluorine

4. D) hydrogen; lithium, sodium

5. E) oxygen; phosphorus, germanium

Answer: C

Diff: 2

Section: 4.2

8) A chemical bond formed when two atoms share one pair of electrons is a ________ bond; it is best described as ________.


2. B) double; ionic


4. D) single; ionic


Answer: C

Diff: 2

Section: 4.2

9) For the dot structure shown the most likely elements are X =________ and Y = ________.

1. A) carbon; hydrogen

2. B) carbon; fluorine

3. C) carbon; oxygen

4. D) hydrogen; carbon

5. E) fluorine; carbon

Answer: B

Diff: 3

Section: 4.2

10) When two atoms share one or more pairs of electrons, a covalent bond is formed.

Answer: TRUE

Diff: 1

Section: 4.2

11) When a non-metal atom bonds with another non-metal atom, an ionic bond is formed.

Answer: FALSE

Diff: 1

Section: 4.2

12) Which point identifies the bond length between the two atoms of the diatomic molecule whose potential energy is shown on the graph?

Answer: C

Diff: 1

Section: 4.2

13) Which point identifies the maximum repulsion between the two atoms of the diatomic molecule whose potential energy is shown in the graph?

Answer: A

Diff: 1

Section: 4.2

14) Which element is most likely to be “X” in the diatomic molecule shown?

1. A) nitrogen

2. B) oxygen

3. C) fluorine

4. D) hydrogen

5. E) helium

Answer: B

Diff: 2

Section: 4.3

15) Which group in the Periodic Table is most likely to contain the element X in the molecule whose dot structure is shown?

1. A) 2A

2. B) 3A

3. C) 4A

4. D) 5A

5. E) 6A

Answer: E

Diff: 2

Section: 4.3

16) A chemical bond formed when two atoms share three pairs of electrons is a ________ bond; it is best described as ________.


2. B) single; covalent

3. C) triple; covalent

4. D) double; ionic

5. E) triple; ionic

Answer: C

Diff: 2

Section: 4.3

17) A triple bond involves the sharing of ________ pairs of electrons between the atoms

1. A) 1

2. B) 2

3. C) 3

4. D) 4

5. E) 5

Answer: C

Diff: 2

Section: 4.3

18) A chemical bond formed when two atoms share six electrons is a ________ bond; it is best described as ________.


2. B) double; ionic


4. D) single; ionic


Answer: E

Diff: 2

Section: 4.3

19) For the structure shown, the most likely elements are X = ________ and Y = ________.

1. A) carbon; oxygen

2. B) carbon; hydrogen

3. C) nitrogen; oxygen

4. D) oxygen; carbon

5. E) oxygen; hydrogen

Answer: D

Diff: 3

Section: 4.3

20) The element in the list given that is most likely to form a coordinate covalent bond is

1. A) H.

2. B) C. 3. C) K.

4. D) Fe.

5. E) Ca.

Answer: D

Diff: 3

Section: 4.4

21) The smallest possible unit of a covalent compound is a(an)

1. A) atom.

2. B) cation.

3. C) formula unit.

4. D) molecule.

5. E) polyatomic ion.

Answer: D

Diff: 1

Section: 4.5

22) The covalent bonding model is most useful in describing which of the following compounds?

1. A) CoCl2

2. B) MgCl2

3. C) NiCl2

4. D) SCl2


Answer: D

Diff: 2

Section: 4.5

23) Which property could describe a covalent compound?

1. A) It conducts electricity when melted.

2. B) It is a gas at room temperature.

3. C) It is composed of a non-metal and a metal.

4. D) It conducts electricity when dissolved in water.


Answer: B

Diff: 2

Section: 4.5

24) Which set of properties would identify an unknown white solid as a molecular compound?

1. Contains a metal.

2. Has a definite crystal structure.

III. Dissolves in water, but not in organic liquids.

1. Melts at 80 degrees Celsius.

2. Does not conduct electricity when melted.

3. A) I, II, III

4. B) I, III, V

5. C) II, III, IV

6. D) II, IV, V

7. E) I, IV, V

Answer: D

Diff: 3

Section: 4.5

25) Which property is most closely associated with covalent molecules?

1. A) It is a gas at room temperature.

2. B) It conducts electricity when dissolved in water.

3. C) It has a very high melting point.

4. D) It is composed of a metal and a nonmetal.

5. E) none of these.

Answer: A

Diff: 3

Section: 4.5

26) Covalent compounds form distinct molecules, and therefore may exist as gases, liquids, or solids at room temperature, depending on the characteristics of the compound.

Answer: TRUE

Diff: 1

Section: 4.5

27) In a Lewis dot structure the electrons which complete an octet but are not located between two atoms are referred to as

1. A) bonding pairs.

2. B) delta minus electrons.

3. C) excess electrons.

4. D) filled shells.

5. E) lone pairs.

Answer: E

Diff: 2

Section: 4.6

28) In forming covalent bonds where the octet rule is obeyed, sulfur usually forms ________ bonds and chlorine usually forms ________ bonds.

1. A) one; one

2. B) two; two

3. C) one; two

4. D) two; one

5. E) six; seven

Answer: D

Diff: 1

Section: 4.7

29) The element least likely to obey the octet rule in forming chemical bonds is

1. A) boron.

2. B) carbon.

3. C) nitrogen.

4. D) oxygen.

5. E) fluorine.

Answer: A

Diff: 1

Section: 4.7

30) The number of valence electrons in the acetic acid molecule (CH3CO2H) is

________.

1. A) 0

2. B) 8

3. C) 16

4. D) 24

5. E) 32

Answer: D

Diff: 2

Section: 4.7

31) The total number of valence electrons in a molecule of SOF2 is ________.

1. A) 26

2. B) 24

3. C) 18

4. D) 20

5. E) 22

Answer: A

Diff: 2

Section: 4.7

32) Explain why it is unlikely that an organic molecule would have an odd number of valence electrons.

Answer: In most molecules, the Lewis dot structure includes bonds that consist of one, two, or three pairs of electrons. The remaining electrons are drawn as lone pairs on one or more atoms. Note that both of these include pairs of electrons. Also most of these atoms obey the octet rule, which means that each atom has eight electrons in its outer shell. The most common exception to the octet rule is hydrogen, which usually has two electrons. Note again that these numbers are all even numbers.

Diff: 3

Section: 4.7

33) A molecule in which the central atom has no lone pairs and forms four single bonds is said to have a ________ shape.

1. A) bent

2. B) linear

3. C) planar

4. D) pyramidal

5. E) tetrahedral

Answer: E

Diff: 1

Section: 4.8

34) The molecule SiCl4 has a ________ shape.

1. A) bent

2. B) linear

3. C) planar

4. D) pyramidal

5. E) tetrahedral

Answer: E

Diff: 1

Section: 4.8

35) A molecule in which the central atom forms three single bonds and has one lone pair is said to have a ________ shape.

1. A) bent

2. B) linear

3. C) planar

4. D) pyramidal

5. E) tetrahedral

Answer: D

Diff: 1

Section: 4.8

36) A molecule in which the central atom forms one double bond and two single bonds is said to have a ________ shape.

1. A) bent

2. B) linear

3. C) trigonal planar

4. D) pyramidal

5. E) tetrahedral

Answer: C

Diff: 1

Section: 4.8

37) What is the molecular geometry of PH3?

1. A) linear

2. B) trigonal planar

3. C) tetrahedral

4. D) bent

5. E) trigonal pyramidal

Answer: E

Diff: 2

Section: 4.8

38) How many double bonds are there in a molecule of SF2?

1. A) 0

2. B) 1

3. C) 2

4. D) 3

5. E) 4

Answer: A

Diff: 2

Section: 4.8

39) According to VSEPR theory, a molecule with three charge clouds including one lone pair would have a ________ shape.

1. A) bent

2. B) linear

3. C) tetrahedral

4. D) trigonal planar t

5. E) pyramidal

Answer: A

Diff: 2

Section: 4.8

40) The water molecule has a ________ geometry because its central atom has ________ bonds and ________ lone pairs of electrons.

1. A) bent; two; two

2. B) linear; two; two

3. C) pyramidal; three; one

4. D) tetrahedral; four; zero

5. E) planar triangular; three; one

Answer: A

Diff: 2

Section: 4.8

41) Draw the Lewis structure for CCl4. What is the molecular geometry of this compound? Is the molecule polar or nonpolar?

Answer:

tetrahedral, non-polar

Diff: 2

Section: 4.7, 4.8

42) The bond angle in the molecule H2S is ________ because the ________.

109. A) exactly 109.5°; S atom has four charge clouds

110. B) greater than 109.5°; lone pairs allow the bond angle to expand

111. C) less than 109.5°; lone pairs force the hydrogen atoms closer together

112. D) exactly 120°; lone pairs are counted as one charge cloud

113. E) exactly 180°; the S atom has two bonds

Answer: C

Diff: 3

Section: 4.8

43) Which of the following molecules has a CCH bond angle of 180°?

1. A) HCCH

2. B) H2CCH2

3. C) H3CCH3

4. D) H3CCHO

5. E) none of them

Answer: A

Diff: 3

Section: 4.8

44) Which element listed is the least electronegative?

1. A) nitrogen

2. B) hydrogen

3. C) oxygen

4. D) fluorine

5. E) chlorine

Answer: B

Diff: 2

Section: 4.9

45) Which element listed is the most electronegative?

1. A) aluminum

2. B) bromine

3. C) chlorine

4. D) iodine

5. E) sodium

Answer: C

Diff: 2

Section: 4.9

46) A section of the Periodic Table containing main group elements is shown. Which bond would be least polar?

1. A) WX

2. B) YZ

3. C) WZ

4. D) WY

5. E) cannot be determined without more specific information

Answer: E

Diff: 2

Section: 4.9

47) A section of the Periodic Table containing main group elements is shown. If the elements W, X, Y, and Z have electronegativity values of 1.0, 2.0, 2.5, and 3.5, respectively, which bond is the least polar?

1. A) WX

2. B) WZ

3. C) XY

4. D) XZ

5. E) YZ

Answer: C

Diff: 3

Section: 4.9

48) A section of the Periodic Table containing main group elements is shown. If the elements W, X, Y, and Z have electronegativity values of 1.0, 2.0, 2.5, and 3.5, respectively, which bond is ionic?

1. A) WY

2. B) WZ

3. C) XY

4. D) XZ

5. E) YZ

Answer: B

Diff: 3

Section: 4.9

49) A bond where the electrons are shared equally is called a(an) ________ bond.

1. A) polar covalent

2. B) coordinate covalent

3. C) nonpolar covalent

4. D) ionic


Answer: C

Diff: 1

Section: 4.9

50) A bond where the electrons are shared unequally is called a(an) ________ bond.

1. A) polar covalent

2. B) coordinate covalent

3. C) nonpolar covalent

4. D) ionic


Answer: A

Diff: 1

Section: 4.9

51) Consider the molecule SiCl4. The electronegativity values for Si and Cl are 1.8 and 3.0, respectively. Based on these values and on consideration of molecular geometry, the Si-Cl bond is ________ and the molecule is ________.

1. A) polar; polar

2. B) nonpolar; nonpolar

3. C) polar; nonpolar

4. D) nonpolar; polar


Answer: C

Diff: 3

Section: 4.10

52) The carbon dioxide molecule is linear. The electronegativities of C and O are 2.5 and 3.5, respectively. Based on these values and on consideration of molecular geometry, the C-O bond is ________ and the molecule is ________.

1. A) polar; polar





Answer: C

Diff: 3

Section: 4.10

53) Consider a bent molecule, such as H2Se, in which the central atom has two lone pairs of electrons. The electronegativities of H and Se are 2.1 and 2.4, respectively. Based on these values and on consideration of molecular geometry, the HSe bond can be considered almost ________ and the molecule is ________.

1. A) polar; polar





Answer: D

Diff: 3

Section: 4.10

54) The VSEPR model or molecular structure requires a knowledge of ________ to predict the geometry of an atom in a molecule.

1. A) the number of atoms bonded to the atom of interest 2. B) the total number of atoms in the molecule

3. C) the number of electron pairs on the atom of interest

4. D) both A and C


Answer: D

Diff: 3

Section: 4.10

55) A molecule that contains three identical polar bonds to the central atom will be ________.

1. A) nonpolar if the geometry is planar triangular

2. B) polar in all cases

3. C) nonpolar in all cases

4. D) impossible to tell the polarity

5. E) either polar or nonpolar depending on the identity of the atoms bonded to the central atom

Answer: A

Diff: 3

Section: 4.10

56) Explain how it is possible for CCl4 to have polar bonds but be a non-polar molecule. A diagram may be helpful in your answer, but it must be explained.

Answer: (This question could also be asked about CF4 or CO2.)

The bonds in this compound are polar due to the difference in their

electronegativity values. However, the molecule is not polar because the molecule is

symmetrical, which means that the polar forces in different directions balance each

other out. In this case, the overall distribution of electrons in the molecule is even.

Diff: 2

Section: 4.10

57) What is the systematic name of ICl3?

1. A) iodine chloride

2. B) iodine(III) chloride

3. C) triiodine chloride

4. D) iodine trichloride

5. E) tri(iodine chloride)

Answer: D

Diff: 1

Section: 4.11

58) The formula for phosphorus pentafluoride is ________.

1. A) PhF5

2. B) PF5

3. C) P5F

4. D) (PF)5

5. E) P5F5

Answer: B

Diff: 1

Section: 4.11

59) Although noble gases do not normally form covalent compounds, XeO3 has been prepared. The systematic name of this compound is

1. A) trioxy xenon.

2. B) trixenon trioxide.

3. C) xenon trioxide.

4. D) xenon(III) oxide.


Answer: C

Diff: 1

Section: 4.11

60) The formula for sulfur hexabromide is ________.

1. A) SF6

2. B) SBr6

3. C) SBr4

4. D) SiBr6

5. E) SiB6

Answer: B

Diff: 1

Section: 4.11

61) The formula for carbon disulfide is ________.

1. A) CS2

2. B) C2S

3. C) CSi2

4. D) CaS2

5. E) (CS)2

Answer: A

Diff: 1

Section: 4.11

62) If SiCl4 is named as a covalent compound, what would it be called?

1. A) silicon chloride

2. B) chlorosilicate

3. C) silicon tetrachloride

4. D) sulfur chloride

5. E) sulfur tetrachloride

Answer: C

Diff: 1

Section: 4.11

63) The compound BrF3 would be called

1. A) boron trifluoride. 2. B) triboron fluoride.

3. C) tri (bromine fluoride).

4. D) tribromine fluoride.

5. E) bromine trifluoride.

Answer: E

Diff: 1

Section: 4.11

Match the following.

1. A) OF2

2. B) BrF5

3. D) N2O4

4. E) SF6

5. F) CO

6. G) ICl

7. H) SO2

8. I) CH4

9. J) IF7

10. K) PCI3

11. L) NH3

64) iodine heptafluoride

Diff: 1

Section: 4.10

65) oxygen difluoride

Diff: 1

Section: 4.10

1. C) CCI4

66) dinitrogen tetroxide

Diff: 1

Section: 4.10

67) bromine pentafluoride

Diff: 1

Section: 4.10

68) ammonia

Diff: 1

Section: 4.10

69) carbon tetrachloride

Diff: 1

Section: 4.10

70) phosphorus trichloride

Diff: 1

Section: 4.10

71) carbon monoxide

Diff: 1

Section: 4.10

72) sulfur hexafluoride

Diff: 1

Section: 4.10

73) sulfur dioxide

Diff: 1

Section: 4.10

74) methane

Diff: 1

Section: 4.10

75) iodine monochloride

Diff: 1

Section: 4.10

Answers: 64) J 65) A 66) D 67) B 68) L 69) C 70) K 71) F 72) E 73) H 74) I 75) G

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Test Bank for Fundamentals of General Organic and ... · Test Bank for Fundamentals of General Organic and Biological Chemistry 7th Edition by McMurry Sample Chapter 4 Molecular Compounds