Deck 9: Molecular Geometry and Covalent Bonding Models

Question 1

The net dipole moment of a water molecule (H₂O) is zero.

Answer 1

False

Question 2

What is the shape of a CO₃^2- ion?

A) Trigonal pyramidal
B) Bent
C) Linear
D) Trigonal planar
E) Bent trigonal

Answer 2

Trigonal planar

Question 3

Compounds with the designation AX₂ will have a(n) _____ geometry.

Answer 3

linear

Question 4

Explain the steps involved in finding the molecular geometry of a compound using the VSEPR model.

Question 5

A single unpaired electron is counted as a lone pair in the VSEPR model.

Question 6

An example of a compound with the designation AX₂E₂ is OF₂.

Question 7

_____ is the arrangement of the bonded atoms in a molecule or polyatomic ion in space.

Question 8

What is the shape of a molecule of SF₄?

A) Seesaw
B) Trigonal bipyramidal
C) Bent
D) Tetrahedral
E) T shaped

Question 9

In the VSEPR model compounds with the designation _____ will be linear.

A) AX₂E
B) AX₂
C) AX₄
D) AX₃E₂
E) AX₅E

Question 10

Which of the following molecules has a linear geometry?

A) NO₂^-
B) H₂O
C) OF₂
D) CO₂
E) SO₂

Question 11

Which of the following molecules has a net dipole moment?

A) CCl₄
B) CO₂
C) BCl₃
D) NHF₂
E) SF₆

Question 12

The most stable form of BrF₃ has both lone pair of electrons in the equatorial plane. In this orientation, what is the number of lone pair - base pair repulsions at 90˚?

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

Question 13

Which of the following molecules has a bent shape?

A) CO₂
B) H₂O
C) CO₃^2-
D) NH₄⁺
E) BCl₃

Question 14

A CO₂ molecule does not have any dipole moment.

Question 15

Explain the geometry of the compound BrF₅ with the designation AX₅E.

Question 16

A sulfur tetrafluoride atom has the AX_mE_n notation AX₄E.

Question 17

Nitrogen dioxide (NO₂) has a linear geometry.

Question 18

Which of the following molecules has an octahedral geometry?

A) I₃^-
B) SF₆
C) BrF₅
D) PCl₅
E) SF₄

Question 19

The bond angle in a molecule of aluminum chloride is _____.

A) 90˚
B) 109.5˚
C) 120˚
D) 60˚
E) 180˚

Question 20

What is the shape of a molecule of BrF₃?

A) Seesaw
B) Trigonal bipyramidal
C) Bent
D) Tetrahedral
E) T shaped

Question 21

Write a note on the hybridization using d orbitals.

Question 22

The BF₆^3- ion has sp³d² hybridized orbitals.

Question 23

In compounds with perfectly symmetrical geometries the dipole moment is _____.

Question 24

Write a note on the hybridization of nitrogen in NH₃.

Question 25

Maximum overlap occurs between orbitals with the same spatial orientation and similar energies.

Question 26

What are the different types of orbitals, both hybrid and nonhybrid, involved in the bonding of a molecule of H₂O?

A) s, p, and sp
B) sp and sp²
C) s and sp³
D) s, sp², and sp³
E) sp and sp³

Question 27

In a molecule of beryllium hydride, the _____ orbitals in the Be bond with the two 1s orbitals from two hydrogen atoms.

A) 1s and 2s
B) 1s and 2p
C) 2s and 2p
D) two sp hybrid
E) three sp² hybrid

Question 28

What is the hybridization of the central atom in SO₄^2-?

A) sp³
B) sp²
C) sp³d²
D) sp³d
E) sp³d³

Question 29

_____ is a process in which atomic orbitals that are similar in energy but not equivalent are combined mathematically to produce sets of equivalent orbitals that are properly oriented to form bonds.

Question 30

What is the hybridization of the central atom in OF₄?

A) sp³
B) sp²
C) sp³d²
D) sp³d
E) sp³d³

Question 31

Carbon, with an atomic number of 6, will form _____ hybrid orbitals to form a molecule of methane.

A) sp
B) sp²
C) sp³
D) sp³d
E) sp³d²

Question 32

In hybridization, the combination of the ns orbital, all three np orbitals, and two nd orbitals gives a set of six equivalent sp³d² hybrid orbitals.

Question 33

_____ is the hybridization of the boron atom in the BF₄^- ion.

A) sp³d
B) sp³d²
C) sp²
D) sp³
E) sp

Question 34

In BF₃, hybrid atomic orbitals are formed from one s and one p orbitals.

Question 35

Ammonia, having the designation AX₃E has a(n) _____ geometry.

Question 36

What is the hybridization of the sulfur atom in H₂S?

A) sp
B) sp²
C) sp³
D) sp³d
E) sp³d²

Question 37

_____ is the excitation of an electron from a filled ns² atomic orbital to an empty np or (n − 1)d valence orbital.

A) Distillation
B) Esterfication
C) Neutralization
D) Hybridization
E) Promotion

Question 38

What is the hybridization of the phosphorous atom in the PF₆^- ion?

A) sp³
B) sp³d
C) sp³d²
D) sp
E) sp²

Question 39

What is the hybridization of the boron atom in BBr₃?

A) sp
B) sp²
C) sp³
D) sp³d
E) sp³d²

Question 40

The overall process of forming a compound with hybrid orbitals will be energetically favorable only if the amount of energy released by the formation of covalent bonds is lesser than the amount of energy used to form the hybrid orbitals.

Question 41

The σ_1s* orbital is an antibonding molecular orbital.

Question 42

What is the number of molecular orbitals formed by the interaction of two 1s atomic orbitals?

A) 1
B) 2
C) 3
D) 4
E) 5

Question 43

A diatomic molecule with a double bond will have a bond order of two.

Question 44

HCl will have a skewed molecular orbital energy-level diagram.

Question 45

What is the bond order of a molecule of Ca₂?

A) 1
B) 0.5
C) 2
D) 0
E) 1.5

Question 46

Diatomic molecules with the bond order _____ have the greatest bond length.

A) 1
B) 0.5
C) 2
D) 0
E) 1.5

Question 47

The interaction between atomic orbitals is greatest when they have the same energy.

Question 48

What is the bond order of a Na₂⁺ ion?

A) 0
B) 0.5
C) 1
D) 1.5
E) 2

Question 49

Which of the following is the correct arrangement of molecular orbitals arranged in an ascending order of their energies?

A) σnp_z, σnp_z*, πnp_x/πnp_y, πnp_x*/πnp_y*
B) σnp_z, πnp_x/πnp_y, σnp_z*, πnp_x*/πnp_y*
C) σnp_z, πnp_x*/πnp_y*, πnp_x/πnp_y, σnp_z*
D) σnp_z, πnp_x/πnp_y, πnp_x*/πnp_y*, σnp_z*
E) σnp_z, πnp_x*/πnp_y*, σnp_z*, πnp_x/πnp_y

Question 50

Which of the following species is the most stable as predicted by the molecular orbital theory?

A) H
B) H⁺
C) H₂
D) H₂⁺
E) H^-

Question 51

A molecule must have as many molecular orbitals as there are atomic orbitals.

Question 52

A 3s orbital, three 3p orbitals, and a 3d orbital hybridize to form _____ sp³d orbitals.

Question 53

The σ_1s orbital contains a region of zero electron probability.

Question 54

What is the bond order of a hydrogen molecule (H₂)?

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

Question 55

The oxygen atom in H₂O has _____ hybrid orbitals.

Question 56

The electron density in the σ_1s* molecular orbital is the greatest between two positively charged nuclei.

Question 57

Which of the following molecular orbitals formed from ns and np atomic orbitals has the lowest energy?

A) $\pi _ { np _ { y } }$
B) $\pi _ { \mathrm { np } _x }$
C) $\pi_{ np_t }$ *
D) $\sigma _ { np _ { x } }$
E) $\sigma _ {np _ { x } }$ *

Question 58

The orbital formed by the hybridization of one s and 2p orbitals is _____.

Question 59

The energy involved in the formation of hybrid orbitals in CF₆^{2 -} is much _____ than the energy released in the formation of C-F bonds.

Question 60

Which of the following species is the most unstable as predicted by the molecular orbital theory?

A) H₂
B) He₂²⁺
C) He₂⁺
D) H₂⁺
E) He₂

Question 61

Two singly occupied 2p_z orbitals can overlap to form a π bonding orbital and a π* antibonding orbital.

Question 62

_____ molecular orbitals are always higher in energy than the parent atomic orbitals.

Question 63

How many electrons are used to fill the π resonance bonds formed in the NO₂^- ion?

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

Question 64

Which of the following types of hybridization is seen in a molecule of methane?

A) no hybridization
B) sp
C) sp²
D) sp³
E) sp³d

Question 65

The _____ of a compound is defined as one-half the net number of bonding electrons.

Question 66

A(n) _____ is an allowed spatial distribution of electrons in a molecule that is associated with a particular orbital energy.

Question 67

What is the hybridization of NO₂^-, given it has a bent geometry?

A) no hybridization
B) sp
C) sp²
D) sp³
E) sp³d

Question 68

The bond order of a molecule increases by 0.5 for every non bonding pair of electrons present.

Question 69

What is the hybridization state of carbon and oxygen in carbonyl chloride (COCl₂), a trigonal planar molecule?

A) no hybridization
B) sp
C) sp²
D) sp³
E) sp³d

Question 70

What are the key points for drawing a molecular orbital diagram for a molecule?

Question 71

_____ diatomic molecules have a molecular orbital energy-level diagram that is skewed or tilted toward the more electronegative element.

Question 72

Explain how molecular orbitals are formed in heteronuclear diatomic molecules.

Question 73

What is the bond order of HBr?

A) 0
B) 0.5
C) 1
D) 2
E) 3

Question 74

What is the bond order of NO₂^- ion?

A) 0
B) 1
C) 1.5
D) 2
E) 2.5

Question 75

The C-C bond length in acetylene is shorter than that in ethane.

Question 76

How many orbitals are involved in the formation of π bond in a molecule of HCN, given that it is linear?

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

Question 77

Retinal is used by the human eye to detect light and has a structure with alternating C=C double bonds.

Question 78

HCN is a linear molecule.

Question 79

_____ molecular orbitals have approximately the same energy as the parent atomic orbitals.

Question 80

What is the bond order of a Cl₂⁺ ion?

A) 0
B) 0.5
C) 1
D) 1.5
E) 3