Question 1

Ethanol has the formula CH3CH2OH. The central carbon atom has a ________ local molecular geometry and ________ hybridization.

Accepted Answer

A)  trigonal planar; sp 
B)  tetrahedral; sp3 
C)  tetrahedral; sp2 
D)  seesaw; sp2 
E)  seesaw; sp3 
A)  trigonal planar; sp 
B)  tetrahedral; sp3 
C)  tetrahedral; sp2 
D)  seesaw; sp2 
E)  seesaw; sp3

Question 2

What is the bond order of B2?

Accepted Answer

A)  0 
B)  1 
C)  2 
D)  3 
E)  1.5 
A)  0 
B)  1 
C)  2 
D)  3 
E)  1.5

Question 3

Which one of the following statements regarding molecular orbitals for diatomic molecules is not correct?

Accepted Answer

A)  An atomic orbital on one atom combines with an atomic orbital on the other atom to form two molecular orbitals. 
B)  2p atomic orbitals only form  $\pi$ and  $\pi$* molecular orbitals. 
C)  2s atomic orbitals only form $\sigma$ and $\sigma$* atomic orbitals. 
D)  ($\sigma$ orbitals are symmetric with respect to rotation around the internuclear axis;  $\pi$ orbitals do not have this symmetry.) 
E)  A bonding molecular orbital describes the build-up of negatively charged electrons between the nuclei. 
A)  An atomic orbital on one atom combines with an atomic orbital on the other atom to form two molecular orbitals. 
B)  2p atomic orbitals only form  $\pi$ and  $\pi$* molecular orbitals. 
C)  2s atomic orbitals only form $\sigma$ and $\sigma$* atomic orbitals. 
D)  ($\sigma$ orbitals are symmetric with respect to rotation around the internuclear axis;  $\pi$ orbitals do not have this symmetry.) 
E)  A bonding molecular orbital describes the build-up of negatively charged electrons between the nuclei.

Question 4

Determine the molecular geometry of CF2Cl2.

Accepted Answer

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

Question 5

Use energy levels of diatomic molecules derived from molecular orbital theory to predict the magnetic properties of the oxygen molecule O2 and the peroxide anion O22-.

Accepted Answer

A)  oxygen (paramagnetic); peroxide (paramagnetic) 
B)  oxygen (paramagnetic); peroxide (diamagnetic) 
C)  oxygen (diamagnetic); peroxide (paramagnetic) 
D)  oxygen (diamagnetic); peroxide (diamagnetic) 
E)  Neither have magnetic properties; only metals have magnetic properties. 
A)  oxygen (paramagnetic); peroxide (paramagnetic) 
B)  oxygen (paramagnetic); peroxide (diamagnetic) 
C)  oxygen (diamagnetic); peroxide (paramagnetic) 
D)  oxygen (diamagnetic); peroxide (diamagnetic) 
E)  Neither have magnetic properties; only metals have magnetic properties.

Question 6

What is the valence electron molecular orbital electron configuration of N2?

Accepted Answer

A)  $$\left( \sigma _ { 2 s } \right) ^ { 2 } \left( \sigma _ { 2 s } ^ { * } \right) ^ { 2 } \left( \pi _ { 2 p } \right) ^ { 4 } \left( \sigma _ { 2 p } \right) ^ { 2 }$$ 
B)  $$\left( \sigma _ { 2 s } \right) ^ { 2 } \left( \sigma _ { 2 s } ^ { * } \right) ^ { 2 } \left( \pi _ { 2 p } \right) ^ { 6 }$$ 
C)  $$\left( \sigma _ { 2 s } \right) ^ { 2 } \left( \sigma _ { 2 s } ^ { * } \right) ^ { 2 } \left( \sigma _ { 2 p } \right) ^ { 2 } \left( \pi _ { 2 p } \right) ^ { 4 }$$ 
D)  $$\left( \sigma _ { 2 s } \right) ^ { 2 } \left( \pi _ { 2 p } \right) ^ { 4 } \left( \sigma _ { 2 p } ^ { * } \right) ^ { 2 } \left( \pi _ { 2 py } ^ { * } \right) ^ { 2 }$$ 
E)  $$\left( \sigma _ { 2 s } \right) ^ { 2 } \left( \sigma _ { 2 s } ^ { * } \right) ^ { 2 } \left( \pi _ { 2 p } \right) ^ { 4 } \left( \pi _ { 2 p } ^ { * } \right) ^ { 2 }$$ 
A)  $$\left( \sigma _ { 2 s } \right) ^ { 2 } \left( \sigma _ { 2 s } ^ { * } \right) ^ { 2 } \left( \pi _ { 2 p } \right) ^ { 4 } \left( \sigma _ { 2 p } \right) ^ { 2 }$$ 
B)  $$\left( \sigma _ { 2 s } \right) ^ { 2 } \left( \sigma _ { 2 s } ^ { * } \right) ^ { 2 } \left( \pi _ { 2 p } \right) ^ { 6 }$$ 
C)  $$\left( \sigma _ { 2 s } \right) ^ { 2 } \left( \sigma _ { 2 s } ^ { * } \right) ^ { 2 } \left( \sigma _ { 2 p } \right) ^ { 2 } \left( \pi _ { 2 p } \right) ^ { 4 }$$ 
D)  $$\left( \sigma _ { 2 s } \right) ^ { 2 } \left( \pi _ { 2 p } \right) ^ { 4 } \left( \sigma _ { 2 p } ^ { * } \right) ^ { 2 } \left( \pi _ { 2 py } ^ { * } \right) ^ { 2 }$$ 
E)  $$\left( \sigma _ { 2 s } \right) ^ { 2 } \left( \sigma _ { 2 s } ^ { * } \right) ^ { 2 } \left( \pi _ { 2 p } \right) ^ { 4 } \left( \pi _ { 2 p } ^ { * } \right) ^ { 2 }$$

Question 7

Which one of the following molecules is paramagnetic? These molecules are described by the MO energy diagram below. These molecular orbitals are formed from the 2s and 2p atomic orbitals.

Accepted Answer

A)  Li2 
B)  C22- 
C)  N22- 
D)  N22+ 
E)  C2 
A)  Li2 
B)  C22- 
C)  N22- 
D)  N22+ 
E)  C2

Question 8

Which electron-pair geometry corresponds to a steric number of 3?

Accepted Answer

A)  linear 
B)  trigonal planar 
C)  tetrahedral 
D)  trigonal bipyramidal 
E)  octahedral 
A)  linear 
B)  trigonal planar 
C)  tetrahedral 
D)  trigonal bipyramidal 
E)  octahedral

Question 9

What is the molecular geometry of SF4?

Accepted Answer

A)  tetrahedral 
B)  square pyramidal 
C)  seesaw 
D)  square planar 
E)  T-shaped 
A)  tetrahedral 
B)  square pyramidal 
C)  seesaw 
D)  square planar 
E)  T-shaped

Question 10

Using the energy-level diagram below, determine the bond order of the PO molecule.

Accepted Answer

A)  2 
B)  2.5 
C)  1.5 
D)  1 
E)  0.5 
A)  2 
B)  2.5 
C)  1.5 
D)  1 
E)  0.5

Question 11

Ethanol has the formula CH3CH2OH. The oxygen atom has a ________ local molecular geometry and ________ hybridization.

Accepted Answer

A)  trigonal planar; sp 
B)  tetrahedral; sp3 
C)  tetrahedral; sp2 
D)  seesaw; sp2 
E)  bent; sp3 
A)  trigonal planar; sp 
B)  tetrahedral; sp3 
C)  tetrahedral; sp2 
D)  seesaw; sp2 
E)  bent; sp3

Question 12

What is the valence electron molecular orbital electron configuration of C2?

Accepted Answer

A)  $\left( \sigma _ { 2 s } \right) ^ { 2 } \left( \sigma _ { 2 s } ^ { * } \right) ^ { 2 } \left( \pi _ { 2 p } \right) ^ { 2 } \left( \pi _ { 2 p } ^ { * } \right) ^ { 2 }$ 
B)  $\left( \sigma _ { 2 s } \right) ^ { 2 } \left( \sigma _ { 2 s } ^ { * } \right) ^ { 2 } \left( \pi _ { 2 p } \right) ^ { 4 }$ 
C)  $\left( \sigma _ { 2 s } \right) ^ { 2 } \left( \sigma _ { 2 s } ^ { * } \right) ^ { 2 } \left( \sigma _ { 2 p } \right) ^ { 2 } \left( \pi _ { 2 p } \right) ^ { 2 }$ 
D)  $\left( \sigma _ { 2 s } \right) ^ { 2 } \left( \pi _ { 2 p } \right) ^ { 4 } \left( \sigma _ { 2 p } ^ { * } \right) ^ { 2 }$ 
E)  $\left( \sigma _ { 2 s } \right) ^ { 2 } \left( \sigma _ { 2 s } ^ { * } \right) ^ { 2 } \left( \pi _ { 2 p } \right) ^ { 2 } \left( \pi _ { 2 p } ^ { * } \right) ^ { 2 }$. 
A)  $\left( \sigma _ { 2 s } \right) ^ { 2 } \left( \sigma _ { 2 s } ^ { * } \right) ^ { 2 } \left( \pi _ { 2 p } \right) ^ { 2 } \left( \pi _ { 2 p } ^ { * } \right) ^ { 2 }$ 
B)  $\left( \sigma _ { 2 s } \right) ^ { 2 } \left( \sigma _ { 2 s } ^ { * } \right) ^ { 2 } \left( \pi _ { 2 p } \right) ^ { 4 }$ 
C)  $\left( \sigma _ { 2 s } \right) ^ { 2 } \left( \sigma _ { 2 s } ^ { * } \right) ^ { 2 } \left( \sigma _ { 2 p } \right) ^ { 2 } \left( \pi _ { 2 p } \right) ^ { 2 }$ 
D)  $\left( \sigma _ { 2 s } \right) ^ { 2 } \left( \pi _ { 2 p } \right) ^ { 4 } \left( \sigma _ { 2 p } ^ { * } \right) ^ { 2 }$ 
E)  $\left( \sigma _ { 2 s } \right) ^ { 2 } \left( \sigma _ { 2 s } ^ { * } \right) ^ { 2 } \left( \pi _ { 2 p } \right) ^ { 2 } \left( \pi _ { 2 p } ^ { * } \right) ^ { 2 }$.

Question 13

Which of the following compounds has a trigonal bipyramidal shape?

Accepted Answer

A)  ICl3 
B)  BrF5 
C)  PCl5 
D)  PH3 
E)  SiF4 
A)  ICl3 
B)  BrF5 
C)  PCl5 
D)  PH3 
E)  SiF4

Question 14

What is the hybridization of the oxygen in the H3O+ ion?

Accepted Answer

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

Question 15

Predict the following three bond angles and give your rationale: N-C-C, O-C   
O, and C-O-H. These bonding patterns appear in amino acids.

Accepted Answer

N-C-C: 109^°,steric number of ce

Question 16

The members of which pair of molecules are enantiomers?

Accepted Answer

A)  I only 
B)  II only 
C)  III only 
D)  I, II, and III 
E)  II and III 
A)  I only 
B)  II only 
C)  III only 
D)  I, II, and III 
E)  II and III

Question 17

Describe the valence bond picture of bonding in ethylene, which is shown below. Identify the number of valence electrons, the number of pi bonds, the number of sigma bonds, and the hybridization of the carbon atomic orbitals.

Accepted Answer

Ethylene has 12 vale

Question 18

How many of the following objects are chiral?
I.a baseball bat with no lettering
II.a plain shoe with no pattern
III.a plain spoon with no pattern
IV.Jack's bean stalk spiraling up a pole

Accepted Answer

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

Question 19

Identify the polar molecule.

Accepted Answer

A)  CF4 
B)  SiH4 
C)  CHCl3 
D)  CS2 
E)  CO2 
A)  CF4 
B)  SiH4 
C)  CHCl3 
D)  CS2 
E)  CO2

Question 20

The bond angle in a trigonal planar structure is ________.

Accepted Answer

A)  90o 
B)  180o 
C)  109o 
D)  120o 
E)  105o 
A)  90o 
B)  180o 
C)  109o 
D)  120o 
E)  105o

Exam 9: Molecular Geometry: Shape Determines Function

Ethanol has the formula CH3CH2OH. The central carbon atom has a ________ local molecular geometry and ________ hybridization.

What is the bond order of B2?

Which one of the following statements regarding molecular orbitals for diatomic molecules is not correct?

Determine the molecular geometry of CF2Cl2.

Use energy levels of diatomic molecules derived from molecular orbital theory to predict the magnetic properties of the oxygen molecule O2 and the peroxide anion O22-.

What is the valence electron molecular orbital electron configuration of N2?

Which one of the following molecules is paramagnetic? These molecules are described by the MO energy diagram below. These molecular orbitals are formed from the 2s and 2p atomic orbitals.

Which electron-pair geometry corresponds to a steric number of 3?

What is the molecular geometry of SF4?

Using the energy-level diagram below, determine the bond order of the PO molecule.

Ethanol has the formula CH3CH2OH. The oxygen atom has a ________ local molecular geometry and ________ hybridization.

What is the valence electron molecular orbital electron configuration of C2?

Which of the following compounds has a trigonal bipyramidal shape?

What is the hybridization of the oxygen in the H3O+ ion?

Predict the following three bond angles and give your rationale: N-C-C, O-C O, and C-O-H. These bonding patterns appear in amino acids.

The members of which pair of molecules are enantiomers?

Describe the valence bond picture of bonding in ethylene, which is shown below. Identify the number of valence electrons, the number of pi bonds, the number of sigma bonds, and the hybridization of the carbon atomic orbitals.

How many of the following objects are chiral? I.a baseball bat with no lettering II.a plain shoe with no pattern III.a plain spoon with no pattern IV.Jack's bean stalk spiraling up a pole

Identify the polar molecule.

The bond angle in a trigonal planar structure is ________.

Matter and Energy: The Origin of the Universe

Atoms, Ions, and Molecules: Matter Starts Here

Stoichiometry: Mass, Formulas, and Reactions

Solution Chemistry: The Hydrosphere

Thermochemistry: Energy Changes in Reactions

Properties of Gases: the Air We Breathe

A Quantum Model of Atoms: Waves and Particles

Chemical Bonds: What Makes a Gas a Greenhouse Gas

Intermolecular Forces: The Uniqueness of Water

Solutions: Properties and Behavior

Solids: Structures and Applications

Organic Chemistry: Fuels, Pharmaceuticals, Materials, and Life

Chemical Kinetics: Reactions in the Air We Breathe

Chemical Equilibrium: How Much Product Does a Reaction Really Make

Acid-Base and Solubility Equilibria: Reactions in Soil and Water

Metal Ions: Colorful and Essential

Thermodynamics: Spontaneous and Nonspontaneous Reactions and Processes

Electrochemistry: the Quest for Clean Energy

Biochemistry: the Compounds of Life

Nuclear Chemistry: Applications to Energy and Medicine

Life and the Periodic Table

Filters

Ethanol has the formula CH₃CH₂OH. The central carbon atom has a local molecular geometry and hybridization.

What is the bond order of B₂?

Determine the molecular geometry of CF₂Cl₂.

Use energy levels of diatomic molecules derived from molecular orbital theory to predict the magnetic properties of the oxygen molecule O₂ and the peroxide anion O₂²^-.

What is the valence electron molecular orbital electron configuration of N₂?

What is the molecular geometry of SF₄?

Ethanol has the formula CH₃CH₂OH. The oxygen atom has a local molecular geometry and hybridization.

What is the valence electron molecular orbital electron configuration of C₂?

What is the hybridization of the oxygen in the H₃O⁺ ion?