Deck 6: The Shape of Molecules

Question 1

In a molecule having four pairs of electrons around the central atom and a pyramidal shape, how many bonding pairs of electrons does the central atom have?

A) 2
B) 1
C) 4
D) 3

Answer 1

3

Question 2

Which of the following molecules is tetrahedral?

A) sulfur trioxide
B) sulfur dioxide
C) sulfur dichloride
D) ammonium ion

Answer 2

ammonium ion

Question 3

Which compound listed below would you expect to have the greatest H-C-H bond angle?

A) CH₂ClF
B) CH₂ CI₂
C) CH₄
D) CH₂O

Answer 3

CH₂O

Question 4

In a molecule having four pairs of electrons around the central atom and a pyramidal shape, how many lone pairs of electrons does the central atom have?

A) 2
B) 1
C) 4
D) 3

Question 5

Which of the following molecules is pyramidal and has a bond angle close to 107° around the central atom?

A) sulfur dioxide
B) boron trifluoride
C) ammonia
D) both A and C

Question 6

When drawing the three-dimensional structure diagram of a molecule the dotted line ________.

A) shows a bond that projects out from the page.
B) shows a bond the goes back behind the page.
C) indicates that the bond is in the plane of the page.
D) One cannot say unless the formula of the molecule is known.

Question 7

Which of the following statements is correct about the bent structure?

A) The bent structure has three bonding electrons pairs with at least one lone pair around the central atom.
B) The bent structure is the shape of the ammonia molecule.
C) The bent structure has bond angles around the central atom very close to the 105°.
D) All above statements are correct.

Question 8

Which of the following molecules is bent and has a bond angle close to 118° around the central atom?

A) sulfur dioxide
B) boron trifluoride
C) ammonia
D) both A and C

Question 9

Which compound listed below has a bond angle of 180° around the central atom?

A) H₂O
B) CO₂
C) CC14
D) NH₃

Question 10

Which of the following statements is correct about the pyramidal structure?

A) The pyramidal structure is very similar to the tetrahedral structure except one electron pair in the pyramidal structure replaces a bond in the tetrahedral one.
B) The pyramidal structure is the shape of the ammonia molecule.
C) The bond angles around the central atom very close to the 107°.
D) All above statements are correct.

Question 11

Which of the following pictures best illustrates a trigonal planar shape for the molecule AB3?

A)
B)
C)
D)

Question 12

Which of the following molecules is bent?

A) water
B) sulfur dioxide
C) carbon dioxide
D) both A and B

Question 13

When drawing the three-dimensional structure diagram of a molecule the bold line ________.

A) shows a bond that projects out from the page.
B) shows a bond that goes back behind the page.
C) indicates that the bond is in the plane of the page.
D) One cannot say unless the formula of the molecule is known.

Question 14

Which of the following molecules is not tetrahedral?

A) carbon tetrachloride
B) chloroform, CHCL₃
C) methane, CH₄
D) boron trifluoride

Question 15

When drawing the three-dimensional structure diagram of a molecule the solid (not bold or dotted) line ________.

A) shows a bond that projects out from the page.
B) shows a bond that goes back behind the page.
C) indicates that the bond is in the plane of the page.
D) One cannot say unless the formula of the molecule is known.

Question 16

Which of the following pictures best illustrates a tetrahedral shape for the molecule AB4?

A)
B)
C)
D)

Question 17

Which of the following molecules is not linear?

A) hydrogen cyanide
B) beryllium chloride
C) boron trifluoride
D) acetylene, C₂H₂

Question 18

In a molecule having three pairs of electrons around a central atom and a trigonal planar shape, how many lone pairs of electrons does the central atom have ?

A) 1
B) 0
C) 2
D) 3

Question 19

In a molecule having four pairs of electrons around the center atom and a bent shape, how many bonding pairs does the central atom have?

A) 2
B) 1
C) 4
D) 3

Question 20

Which of the following molecules is linear?

A) hydrogen chloride
B) ethane, C₂H₆
C) ethene, C₂H₄
D) ammonia

Question 21

What is the molecular shape of CH₂O?

A) tetrahedral
B) bent
C) trigonal planar
D) pyramidal

Question 22

Which of the following compounds would you expect to be the most polar molecule?

A) H₂S
B) H₂Se
C) H₂Te
D) H₂O

Question 23

What is the steric number of the central atom in boron trichloride?

A) 1
B) 2
C) 3
D) 4

Question 24

Which of the following compounds is non-polar?

A) acetylene, C₂H₂
B) ethene, C₂H₄
C) methane
D) All of the above are non-polar.

Question 25

Which of the following compounds is pure covalent?

A) H₂CO
B) CL₂SO
C) O₂
D) CO

Question 26

Which of the following sulfur-containing compounds or ions is not polar?

A) SO₃
B) H₂S
C) HS-
D) SOCL₂

Question 27

Which of the following compounds is polar?

A) SO₃
B) CO₂
C) CS2
D) H₂CO

Question 28

What is the steric number of the central atom in carbon disulfide?

A) 1
B) 2
C) 3
D) 4

Question 29

Which of the following compounds contains bonds that are the most polar (greatest electronegativity difference between hydrogen and the central atom)?

A) H₂O
B) H₂S
C) H₂Se
D) H₂Te

Question 30

Which of the following compounds would be soluble in a nonpolar solvent?

A) H₂S
B) NH₃
C) CC14
D) SO₂

Question 31

What is the molecular shape of CC14?

A) tetrahedral
B) pyramidal
C) linear
D) bent

Question 32

Which of the following nitrogen-containing compounds is least polar?

A) NH₃
B) CH₃ - N = N - CH₃
C) (CH₃ CH₂)3N
D) (CH₃)3N

Question 33

Which of the following compounds is non-polar?

A) SO₂
B) CH₂O
C) CS2
D) SOCL₂

Question 34

The angle around boron in boron trifluoride is ________.

A) 60°
B) 90°
C) 109.5°
D) 120°

Question 35

Which of the following chlorine-containing compounds is not polar?

A) CHCL₃
B) CH₂CL₂
C) HCl
D) CCl4

Question 36

The angle around carbon in hydrogen cyanide is ________.

A) 105°
B) 109.5°
C) 120°
D) 180°

Question 37

The angle around nitrogen in the ammonium ion is ________.

A) 60°
B) 90°
C) 109.5°
D) 120°

Question 38

What is the steric number of the central atom in CH₄?

A) 1
B) 2
C) 3
D) 4

Question 39

What is the molecular shape of H₂S?

A) tetrahedral
B) pyramidal
C) linear
D) bent

Question 40

What is the molecular shape of NO₂-

A) tetrahedral
B) pyramidal
C) linear
D) bent

Question 41

Dipole dipole forces are an important factor to consider in determining whether or not a substance will dissolve in water (a molecule which has a dipole). Which of the following compounds would you expect to be the most soluble in water?

A) CCl4
B) NH₃
C) N₂
D) CO₂

Question 42

The bond angle in carbon tetrachloride is 109.5°.

Question 43

Which of the following compounds will be the least soluble in water?

A) CH₃OH
B) CH₄
C) NH₃
D) CH₃CH₂OH

Question 44

Bonds are regions of negative charge and therefore repel each other.

Question 45

In which of the three phases of matter would you expect hydrogen bonding between water molecules to be the strongest?

A) solid phase (H₂O Os very close together)
B) liquid phase (H₂O Os more separated than solid phase)
C) gas phase (H₂O Os much farther apart than liquid phase)
D) It is equally strong in all three phases.

Question 46

SO₂, HCN and CO₂ are linear.

Question 47

The pyramidal structure is the tetrahedral arrangement minus a bond but with a lone pair.

Question 48

In the VSEPR model the multiple bond is treated as a single electron group, just the way a single bond is treated.

Question 49

Which of the following compounds is polar?

A) N₂
B) O₂
C) SOCL₂
D) CO₂

Question 50

When determining the shape of a molecule, count all electron groups around the central atom.

Question 51

When naming the shape of a molecule count only the lone pairs.

Question 52

Which of the following compounds will be affected by the presence of an electric field?

A) H₂
B) O₂
C) HCl
D) N₂

Question 53

Sulfur dioxide is linear.

Question 54

Any molecule of the form AX₃ is tetrahedral.

Question 55

The ball-and-stick model emphasizes the bonding pattern.

Question 56

When drawing the three-dimensional structure diagram of a molecule the bold line goes back behind the page.

Question 57

The angle around the central atom in the pyramidal structure is very close to that of the tetrahedral one.

Question 58

NH₃, CH₃-, and PCL₃ are pyramidal.

Question 59

The bond angle in ammonia is 109.5°.

Question 60

Dipole dipole forces are an important factor to consider in determining whether or not a substance will dissolve in water (a molecule which has a dipole). Which of the following compounds would you expect to be the least soluble in water?

A) BF₃
B) NH₃
C) HF
D) H₂S

Question 61

Carbon tetrachloride contains polar bonds and is a polar molecule.

Question 62

Use VSEPR theory to predict the shape of the molecule or complex ion shown. Draw a Lewis dot structure to assist you in determining these shapes.
H₂S

Question 63

Carbon tetrachloride is polar.

Question 64

Use VSEPR theory to predict the shape of the molecule or complex ion shown. Draw a Lewis dot structure to assist you in determining these shapes.
NO+

Question 65

Use VSEPR theory to predict the shape of the molecule or complex ion shown. Draw a Lewis dot structure to assist you in determining these shapes.
PO₄-

Question 66

Use VSEPR theory to predict the shape of the molecule or complex ion shown. Draw a Lewis dot structure to assist you in determining these shapes.
CN-

Question 67

Use VSEPR theory to predict the shape of the molecule or complex ion shown. Draw a Lewis dot structure to assist you in determining these shapes.
SO₃

Question 68

Use VSEPR theory to predict the shape of the molecule or complex ion shown. Draw a Lewis dot structure to assist you in determining these shapes.
CHCl₃

Question 69

Use VSEPR theory to predict the shape of the molecule or complex ion shown. Draw a Lewis dot structure to assist you in determining these shapes.
PH₃

Question 70

Use VSEPR theory to predict the shape of the molecule or complex ion shown. Draw a Lewis dot structure to assist you in determining these shapes.
SO₂

Question 71

Use VSEPR theory to predict the shape of the molecule or complex ion shown. Draw a Lewis dot structure to assist you in determining these shapes.
CS₂

Question 72

Use VSEPR theory to predict the shape of the molecule or complex ion shown. Draw a Lewis dot structure to assist you in determining these shapes.
CO₃^2-

Question 73

The difference in electronegativity between H and in HF is higher than that between H and Cl in HCl.

Question 74

A polar covalent compound is unaffected by the presence of an electric field.

Question 75

Use VSEPR theory to predict the shape of the molecule or complex ion shown. Draw a Lewis dot structure to assist you in determining these shapes.
NO₃-

Question 76

Use VSEPR theory to predict the shape of the molecule or complex ion shown. Draw a Lewis dot structure to assist you in determining these shapes.
O₃ (ozone)

Question 77

Compounds with polar bonds may be nonpolar.

Question 78

Carbon dioxide contains polar bonds and is a nonpolar molecule.

Question 79

SO₃, CO₂, and CS₂ are all non-polar.

Question 80

Use VSEPR theory to predict the shape of the molecule or complex ion shown. Draw a Lewis dot structure to assist you in determining these shapes.
SCN-