Deck 6: The Shape of Molecules

Question 1

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

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

Answer 1

has its angles around the central atom very close to the 105°

Question 2

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

Answer 2

BF₃

Question 3

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

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

Answer 3

projects out from the page

Question 4

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

A)H₂O
B)CO₂
C)CC1₄
D)NH₃

Question 5

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

A)

B)

C)

D)

Question 6

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

A)

B)

C)

D)

Question 7

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 8

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

A)is very similar to the tetrahedral structure except that the pair electrons in the pyramidal structure replaces a bond in the tetrahedral one
B)is the shape of the ammonia molecule
C)has its angles around the central atom very close to the 109°
D)All above statements are correct.

Question 9

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 10

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 11

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

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

Question 12

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 13

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

Question 14

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

A)H₂S
B)H₂Se
C)H₂Te
D)H₂O

Question 15

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

Question 16

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

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

Question 17

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

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

Question 18

Which of the following is linear?

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

Question 19

Which of the following molecules is not linear?

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

Question 20

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 21

Which of the following bonds will have the largest difference in electronegativity?

A)HBr
B)NaF
C)H₂
D)HS^-

Question 22

Which of the following is tetrahedral?

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

Question 23

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

A)CH₃OH
B)CH₄
C)NH₃
D)CH₃CH₂OH

Question 24

Which of the following multiple-bond compounds is polar?

A)N₂
B)O₂
C)SOCl₂
D)CO₂

Question 25

The angle around boron in boron trifluoride is ________.

A)60°
B)90°
C)109°
D)120°

Question 26

The angle around nitrogen in the ammonium ion is ________.

A)60°
B)90°
C)109°
D)120°

Question 27

Which of the following is non-polar?

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

Question 28

Which of the following is pyramidal and has an angle close to 109° around the central atom?

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

Question 29

The angle around carbon in hydrogen cyanide is ________.

A)105°
B)109°
C)120°
D)180°

Question 30

Which of the double-bond bearing compounds is polar?

A)SO₃
B)CO₂
C)CS₂
D)H₂CO

Question 31

Which of the following sulfur-containing species is not polar?

A)SO₃
B)H₂S
C)HS^-
D)SOCl₂

Question 32

Which of the following is not tetrahedral?

A)carbon tetrachloride
B)chloroform, CHCl₃
C)ethane, C₂H₆
D)boron trifluoride

Question 33

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

A)CHCl₃
B)CH₂Cl₂
C)HCl
D)CCl₄

Question 34

Which of the following multiple-bond compounds is pure covalent?

A)H₂CO
B)Cl₂SO
C)O₂
D)CO

Question 35

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

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

Question 36

Which of the following bonds will have the smallest difference in electronegativity?

A)HBr
B)NaF
C)H₂
D)HS^-

Question 37

Which of the following double-bond bearing compounds is non-polar?

A)SO₂
B)CH₂O
C)CS₂
D)SOCl₂

Question 38

Which of the following is bent?

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

Question 39

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

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

Question 40

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

A)H₂
B)O₂
C)HCl
D)N₂

Question 41

Carbon tetrachloride contains polar bonds and is a polar molecule.

Question 42

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

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

Question 43

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

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

Question 44

What is the molecular shape of CC1₄?

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

Question 45

Carbon dioxide contains polar bonds and is a nonpolar molecule.

Question 46

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

Question 47

What is the molecular shape of CH₂O?

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

Question 48

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

Question 49

Any molecule of the form AX₃ is tetrahedral.

Question 50

Carbon tetrachloride is polar.

Question 51

All of the following SO₃, CO₂, CS₂ are non-polar.

Question 52

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

Question 53

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

A)H₂S
B)NH₃
C)CC1₄
D)SO₂

Question 54

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

Question 55

All of the following SO₂, HCl, CO₂ are linear.

Question 56

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

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

Question 57

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

Question 58

All of the following O₂, HI, CO₂ are linear.

Question 59

What is the molecular shape of NO₂^-

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

Question 60

What is the molecular shape of H₂S?

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

Question 61

Judge whether or not the molecule or polyatomic ion shown is polar or non-polar. Draw a dipole vector to indicate the direction of any net polarity.
PH₃

Question 62

The bond angle in ammonia is 109°.

Question 63

Judge whether or not the molecule or polyatomic ion shown is polar or non-polar. Draw a dipole vector to indicate the direction of any net polarity.
O₃ (ozone)

Question 64

Sulfur dioxide is linear.

Question 65

Judge whether or not the molecule or polyatomic ion shown is polar or non-polar. Draw a dipole vector to indicate the direction of any net polarity.
H₂S

Question 66

Judge whether or not the molecule or polyatomic ion shown is polar or non-polar. Draw a dipole vector to indicate the direction of any net polarity.
CN^-

Question 67

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

Question 68

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

Question 69

Judge whether or not the molecule or polyatomic ion shown is polar or non-polar. Draw a dipole vector to indicate the direction of any net polarity.
SO₂

Question 70

One can say with certainty that the pyramidal structure is the tetrahedral arrangement minus a bond but with a lone pair.

Question 71

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

Question 72

Judge whether or not the molecule or polyatomic ion shown is polar or non-polar. Draw a dipole vector to indicate the direction of any net polarity.
SCN^-

Question 73

Judge whether or not the molecule or polyatomic ion shown is polar or non-polar. Draw a dipole vector to indicate the direction of any net polarity.
CHC1₃

Question 74

Compounds with polar bonds may be nonpolar.

Question 75

Judge whether or not the molecule or polyatomic ion shown is polar or non-polar. Draw a dipole vector to indicate the direction of any net polarity.
CS₂

Question 76

Judge whether or not the molecule or polyatomic ion shown is polar or non-polar. Draw a dipole vector to indicate the direction of any net polarity.
NO₃^-

Question 77

The bond angle in carbon tetrachloride is 109°.

Question 78

Judge whether or not the molecule or polyatomic ion shown is polar or non-polar. Draw a dipole vector to indicate the direction of any net polarity.
PO₄^3-

Question 79

Judge whether or not the molecule or polyatomic ion shown is polar or non-polar. Draw a dipole vector to indicate the direction of any net polarity.
CO₃^2-

Question 80

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