Deck 4: Molecular Geometry, Polarity, and Intermolecular

Question 1

Propane is a fuel commonly used in barbeques and to heat homes.It has the structure shown below.Does propane have a permanent dipole?

A) Yes.The carbon is partially negative, and the hydrogen is partially positive.
B) Yes.The carbon is partially positive, and the hydrogen is partially negative.
C) Yes.One side of the molecule is always partially positive, and the other side is partially negative.
D) No.Propane has a temporary dipole.
E) No.Propane never displays any dipole at all.

Answer 1

No.Propane has a temporary dipole.

Question 2

An atom in a molecule has one lone pair and three atoms bonded to it.What is the molecular geometry of this atom?

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

Answer 2

trigonal pyramidal

Question 3

The electronegativity difference between C and O is ____ , and therefore, the C-O bond is a(n)____ bond.

A) 1.0; nonpolar covalent
B) 6.0; polar covalent
C) -1.0; ionic
D) 6.0; nonpolar covalent
E) 1.0; polar covalent

Answer 3

1.0; polar covalent

Question 4

What is the electron geometry of the carbon in dichloromethane (CH₂Cl₂)?

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

Question 5

The electronegativity difference between K and Cl is ____, and therefore, the Mg-Cl bond is a(n)____ bond.

A) 2.2; polar covalent
B) -2.2; nonpolar covalent
C) 3.8; ionic
D) -3.8; nonpolar covalent
E) 2.2; ionic

Question 6

What is the electron geometry of the groups around the nitrogen atom indicated with arrow II?

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

Question 7

What is the molecular geometry of the carbon in dichloromethane (CH₂Cl₂)?

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

Question 8

Which figure BEST illustrates how two molecules of formaldehyde (CH₂O)interact?

A) structure a
B) structure b
C) structure c
D) structure d
E) structure e

Question 9

Electrostatic interactions between positive and negative ions are called _______.

A) ionic bonding
B) covalent bonding
C) dispersion forces
D) dipole-dipole forces
E) hydrogen bonding forces

Question 10

An atom, X, has a tetrahedral electron geometry but a trigonal pyramidal molecular geometry.How many atoms is atom X bonded to?

A) 0
B) 1
C) 2
D) 3
E) 4

Question 11

Which of the following covalent compounds is polar?

A) structure a
B) structure b
C) structure c
D) structure d
E) all of these molecules are polar.

Question 12

Chloroform (CHCl₃)is an anesthetic and is also used in the synthesis of ozone-damaging refrigerants called CFCs.What is the correct Lewis dot structure for chloroform?

A) structure a
B) structure b
C) structure c
D) structure d
E) structure e

Question 13

When determining the shape of a molecule, it is necessary to count electron groups.Which of the following is an electron group?

A) a single bond
B) a double bond
C) a triple bond
D) a nonbonding pair of electrons
E) All of these are electron groups.

Question 14

Nitrogen trichloride, once used as a bleaching agent, causes neurological disorder and was banned in 1949.Which of the following is a correct Lewis structure for nitrogen trichloride (NCl₃)?

A) structure a
B) structure b
C) structure c
D) structure d

Question 15

What is the molecular geometry of the atoms bonded to oxygen in methanol, shown below?

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

Question 16

Does propane (shown)or octane (C₈H₁₈)exhibit stronger dispersion forces?

A) Propane.The smaller molecules can get closer to one another.
B) Propane.It has a larger permanent dipole.
C) Octane.It has a larger permanent dipole.
D) Octane.It has more electrons.
E) They both have the same amount of forces.

Question 17

How many electron groups do the carbon atoms in ethylene (C₂H₄)have?

A) They both have one group.
B) They both have two groups.
C) They both have three groups.
D) They both have four groups.
E) One has two groups, and the other has four groups.

Question 18

Which of the molecules below exhibits hydrogen bonding forces between like molecules?

A) a only
B) a and b
C) a, b, and c
D) a, b, c, and d
E) e only

Question 19

How many nonbonding pairs are on the carbon in dichloromethane (CH₂Cl₂)?

A) 0
B) 1
C) 2
D) 3
E) 4

Question 20

Which of the following bonds is nonpolar?

A) C-O
B) O-F
C) C-F
D) C-H
E) H-F

Question 21

The electronegativity difference between C and H is ____, and therefore, the C-H bond is a(n)____ bond.

A) 0.4; nonpolar covalent
B) 0.4; polar covalent
C) 4.6; ionic
D) -0.4; nonpolar covalent
E) 4.6; polar covalent

Question 22

Does formaldehyde have a permanent dipole?

A) Yes.The carbon is partially negative, and the oxygen is partially positive.
B) Yes.The carbon is partially negative, and the hydrogen is partially positive.
C) Yes.The carbon is partially positive, and the oxygen is partially negative.
D) Yes.The carbon is partially positive, and the hydrogen is partially negative.
E) No.Formaldehyde only has a temporary dipole.

Question 23

What is the molecular geometry of the atoms bonded to the nitrogen atom indicated with arrow II?

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

Question 24

Which element is the MOST electronegative?

A) fluorine
B) bromine
C) chlorine
D) iodine
E) boron

Question 25

A polar molecule is one that has

A) one large atom and one small atom.
B) an even distribution of charge.
C) a positive or negative charge.
D) a more positive side and a more negative side.
E) only polar atoms.

Question 26

In molecules with permanent dipoles, _______ are the attraction of the positive end of a dipole on one molecule with the negative end of the dipole on another molecule.

A) ionic bonding
B) covalent bonding
C) dispersion forces
D) dipole-dipole forces
E) hydrogen bonding forces

Question 27

What is the strongest type of intermolecular force of attraction that a caffeine molecule could form with other caffeine molecules?

A) dispersion forces
B) nonpolar covalent bonds
C) hydrogen bonds
D) covalent bonds
E) dipole-dipole interactions

Question 28

How does VSEPR theory explain the electron group geometry of a molecule?

A) The bonds arrange themselves at 90º angles.
B) The groups are arranged as far away from each other as possible.
C) The groups are as close to each other as possible.
D) The bonds are close together but far away from the nonbonding pairs.
E) None of these answers explains VSEPR theory.

Question 29

Why do electron groups around a central atom arrange themselves as far apart from one another as possible, while still remaining attached to the central atom?

A) Actually, electrons don't do this, but atoms do.
B) The like charges of the electrons attract each other.
C) The protons direct the electrons to do this.
D) The like charges of the electrons repel each other.
E) There is no reason for this arrangement; it is just observed to be that way.

Question 30

What is the strongest type of intermolecular force of attraction that a caffeine molecule could form with water?

A) dispersion forces
B) nonpolar covalent bonds
C) hydrogen bonds
D) covalent bonds
E) dipole-dipole interactions

Question 31

Atom X in a molecule has tetrahedral electron geometry but a bent molecular geometry.Which of the following describes the identity of atom X?

A) Atom X is the oxygen in a molecule of H₂O.
B) Atom X is the nitrogen in a molecule of NH₃.
C) Atom X is the hydrogen in a molecule of CH₄.
D) Atom X is the carbon in a molecule of CH₄.
E) Atom X could be any of these atoms.

Question 32

Is chloroform (CHCl₃)a polar molecule?

A) No.All polarities cancel out.
B) Yes.All molecules with polar bonds are polar.
C) No.The bonds in chloroform are not polar.
D) Yes.The polarities do not cancel out.
E) No.Carbon compounds cannot be polar.

Question 33

Does ethanol have a permanent dipole?

A) Yes.The carbon is partially negative, and the oxygen is partially positive.
B) Yes.The carbon is partially negative, and the hydrogen is partially positive.
C) Yes.The hydrogen is partially positive, and the oxygen is partially negative.
D) Yes.The oxygen is partially positive, and the hydrogen is partially negative.
E) No.Ethanol only has a temporary dipole.

Question 34

What is the angle between groups of electrons for an atom that has a linear electron geometry?

A) 90°
B) 120°
C) 180°
D) 109.5°
E) 360°

Question 35

Tamoxifen has some key similarities to estradiol.Which of the following statements describes one of the similarities?

A) Tamoxifen has the same structure as estradiol.
B) Tamoxifen has the same number of atoms as estradiol.
C) Tamoxifen performs the same function in the cell as estradiol.
D) Tamoxifen binds to the same receptor as estradiol.
E) Tamoxifen deforms the shape of the estrogen receptor in the same way as estradiol.

Question 36

Which element is the LEAST electronegative?

A) potassium
B) hydrogen
C) fluorine
D) carbon
E) oxygen

Question 37

An atom in a molecule has two lone pairs and two atoms bonded to it.What is the molecular geometry of this atom?

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

Question 38

Which of the following steps is done first to determine the molecular geometry of dichloromethane (CH₂Cl₂)?

A) Calculate the molecular weight.
B) Look up the bond angle of a H-C-H bond.
C) Determine the electron geometry.
D) Construct the Lewis structure.
E) The molecular geometry can be determined without doing any prior steps.

Question 39

Which type(s)of molecular model illustrate the three-dimensional shape of a molecule?

A) ball-and-stick
B) Lewis dot structure
C) space-filling
D) Lewis dot and space-filling
E) ball-and-stick and space-filling

Question 40

Which elements have the highest electronegativity and why?

A) Nonmetals.They accept electrons in order to attain an octet.
B) Metals.They accept electrons in order to attain an octet.
C) Nonmetals.They donate electrons in order to attain an octet.
D) Metals.They donate electrons in order to attain an octet.
E) Transition metals.They can have different charges.

Question 41

Which of the following molecules contains polar bonds but is nonpolar overall?

A) Cl₂
B) CF₄
C) H₂O
D) N₂
E) NH₃

Question 42

What is the molecular geometry of each carbon in ethylene (C₂H₄)?

A) They are both linear.
B) They are both trigonal planar.
C) They are both bent.
D) One is bent, and the other is trigonal planar.
E) One is bent, and the other is tetrahedral.

Question 43

Formaldehyde is used as a preservative and disinfectant.It has the structure shown below.What is the strongest type of intermolecular interaction attracting molecules of formaldehyde together?

A) ionic bonding
B) covalent bonding
C) dispersion forces
D) dipole-dipole forces
E) hydrogen bonding forces

Question 44

An atom in a molecule has a trigonal planar molecular geometry and a formula of MX₃.What is the angle between the atoms in this molecule?

A) 360º
B) 180º
C) 120º
D) 109.5º
E) 90º

Question 45

Which bonds in caffeine are polar covalent bonds?

A) All the bonds are polar covalent.
B) the C-N bonds only
C) the C=C, C-C and C-H bonds
D) the C-N, C=O, and C=N bonds
E) the O-H bonds

Question 46

How does estradiol stimulate the growth of breast cancer cells?

A) Estradiol is a toxin, and all toxins stimulate the growth and spread of cancer.
B) Estradiol is a damaged estrogen that stimulates the growth of damaged cell.
C) Estradiol binds to breast cancer cell receptors as well as receptors found in other parts of the body.
D) Once a woman reaches adulthood, estradiol has no purpose in the body and so it causes breast cancer.
E) All of the above statements about estradiol are true.

Question 47

Which BEST describes your reasoning in answering the previous question?

A) Ethanol is nonpolar.
B) Ethanol has polar bonds.
C) Ethanol contains an O-H bond.
D) Ethanol forms ions in solutions.
E) Ethanol does not contain any metals.

Question 48

The only interactions between two or more molecules of a nonpolar material such as methane (CH₄)are _______ because these molecules do not have permanent dipoles.

A) ionic bonding
B) covalent bonding
C) dispersion forces
D) dipole-dipole forces
E) hydrogen bonding forces

Question 49

What is the angle between groups of electrons for an atom that has a tetrahedral electron geometry?

A) 90°
B) 120°
C) 180°
D) 109.5°
E) 360°

Question 50

What is the strongest type of intermolecular interaction attracting molecules of propane together?

A) ionic bonding
B) covalent bonding
C) dispersion forces
D) dipole-dipole forces
E) hydrogen bonding forces

Question 51

Electronegativity is a measure of an atom's ability to

A) become an anion.
B) ionize.
C) draw electrons to itself in a covalent bond.
D) accept an electron from a metal.
E) donate an electron to a nonmetal.

Question 52

Which figure BEST illustrates how two molecules of ethanol interact?

A) structure a
B) structure b
C) structure c
D) structure d
E) structure e

Question 53

Which bond is correctly labeled with a dipole arrow?

A) structure a
B) structure b
C) structure c
D) structure d
E) structure e

Question 54

Which of the following interactions is the strongest?

A) dipole-dipole forces
B) hydrogen bonding forces
C) dispersion forces
D) covalent bond
E) All of the above interactions have the same strength.

Question 55

Which of the molecules below does NOT have a permanent dipole?

A) structure a
B) structure b
C) structure c
D) structure d
E) structure e

Question 56

What is the purpose of Valence Shell Electron Pair Repulsion (VSEPR)theory?

A) It predicts which atom is the central atom in a Lewis structure.
B) It identifies the lone pair and valence electrons in a molecule.
C) It determines the shape of a molecule from the Lewis structure.
D) It determines the shape of a molecule from a molecular model.
E) It determines the arrangement of valence electrons in an atom.

Question 57

Ethanol is an alcohol found in wine and beer, and it is also used as a fuel.It has the structure shown below.What is the strongest type of intermolecular interaction attracting molecules of ethanol together?

A) ionic bonding
B) covalent bonding
C) dispersion forces
D) dipole-dipole forces
E) hydrogen bonding forces

Question 58

In addition to single bonds, which of the following electron groups are on the nitrogen of nitrogen trichloride (NCl₃)?

A) a double bond
B) a triple bond
C) a single electron
D) a lone pair of electrons
E) None of the above electron groups are on the nitrogen.

Question 59

Which molecule below exhibits the strongest intermolecular forces of attraction?

A) structure a
B) structure b
C) structure c
D) structure d
E) structure e

Question 60

What is the electron geometry of the nitrogen atom in nitrogen trichloride (NCl₃)?

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

Question 61

What is the molecular geometry of the carbon in formaldehyde, shown below?

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

Question 62

Ethylene is used as a starting material in making plastics.It has a molecular formula of C₂H₄.Which of the following structures is the correct Lewis structure for ethylene?

A) structure a
B) structure b
C) structure c
D) structure d
E) structure e

Question 63

What is the electron geometry of the carbon in formaldehyde, shown below?

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

Question 64

Which molecules exhibit the strongest intermolecular forces of attraction?

A) structure a
B) structure b
C) structure c
D) structure d
E) They all have the same strength of intermolecular force because they are all nonpolar molecules

Question 65

What is the molecular geometry of carbon in chloroform (CHCl₃)?

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

Question 66

What is the electron geometry of the carbon in chloroform (CHCl₃)?

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

Question 67

Antiestrogens are one type of molecule that can be used to treat breast cancer.Which of the following characteristics should be included in the design of a novel antiestrogen?

A) The molecule should bind to the estrogen receptor on breast cancer cells.
B) The molecule should not interfere with the normal role of estrogen.
C) The molecule should prevent the activation of genes in breast cancer cells.
D) The molecule should not have negative side effects.
E) All of the above are design considerations.

Question 68

In addition to single bonds, which of the following electron groups do the carbon atoms in ethylene (C₂H₄)have?

A) a double bond
B) a triple bond
C) a single electron
D) a lone pair of electrons
E) None of the above electron groups is correct.

Question 69

Which of these molecules exhibits dipole-dipole forces but cannot hydrogen bond with like molecules?

A) b only
B) a, b, and c
C) b, c, and e
D) a, b, c, and e
E) d only

Question 70

Which of the following covalent bonds is polar?

A) C-C
B) C-H
C) O-Cl
D) Cl-Cl
E) Mg-Cl

Question 71

Does chloroform (CHCl₃)contain polar bonds?

A) Yes.All of the bonds in chloroform are polar.
B) Yes.The C-Cl bond in chloroform is polar.
C) Yes.The C-H bond in chloroform is polar.
D) Yes.All atoms in chloroform are highly electronegative.
E) No.All bonds in chloroform are nonpolar.

Question 72

What is the H-C-H bond angle of each carbon in ethylene (C₂H₄)?

A) Both are 180º.
B) Both are 120º.
C) Both are 109.5º.
D) One is 180º, and the other is 109.5º.
E) One is 120º, and the other is 109.5º.

Question 73

Which of the bonds in the following molecule are polar covalent?

A) C-H and O-H only
B) C-O and O-H only
C) C-O only
D) C-C and C-O
E) O-H only

Question 74

How many electron groups are found on the nitrogen atom of nitrogen trichloride (NCl₃)?

A) one
B) two
C) three
D) four
E) five

Question 75

Which element is the MOST electronegative?

A) nitrogen
B) carbon
C) oxygen
D) sulfur
E) selenium

Question 76

______ is the sharing of electrons between two atoms and is much stronger than intermolecular forces of attraction.

A) Ionic bonding
B) Covalent bonding
C) Dispersion forces
D) Dipole-dipole forces
E) Hydrogen bonding forces

Question 77

How many atoms are bonded to the carbon in dichloromethane (CH₂Cl₂)?

A) 0
B) 1
C) 2
D) 3
E) 4

Question 78

What is the angle between groups of electrons for an atom that has a trigonal planar electron geometry?

A) 90°
B) 120°
C) 180°
D) 109.5°
E) 360°

Question 79

Which of the bonds in the following molecule are polar covalent?

A) C-H only
B) C-N only
C) C=O only
D) C-N and C=O
E) C-N, C=O, and N-H

Question 80

What is the molecular geometry of nitrogen trichloride (NCl₃)?

A) trigonal planar
B) bent
C) trigonal pyramidal.
D) nitrogen is tetrahedral
E) linear