Question 1

How many σ- and π-bonds,respectively,are there in phenylisothiocyanate,C6H5NCS? Ignore the C-H bonds in your counting.

Accepted Answer

A) 9 and 5 
B) 8 and 4 
C) 5 and 5 
D) 9 and 2 
A) 9 and 5 
B) 8 and 4 
C) 5 and 5 
D) 9 and 2

Question 2

For the molecule

Accepted Answer

A) the hybridization for C is sp3  
B) the hybridization for N is sp2  
C) the hybridization for O is sp3  
D) N is not hybridized 
E) the hybridization for C is sp2  
A) the hybridization for C is sp3  
B) the hybridization for N is sp2  
C) the hybridization for O is sp3  
D) N is not hybridized 
E) the hybridization for C is sp2

Question 3

According to MO theory,all of the following have a bond order of 2 EXCEPT:

Accepted Answer

A) NO 
B) CN+ 
C) C2 
D) O2 
A) NO 
B) CN+ 
C) C2 
D) O2

Question 4

How many σ bonds and how many π bonds are present in the carbonic acid molecule,H2CO3?

Accepted Answer

A) 2σ/4π 
B) 3σ/3π 
C) 4σ/2π 
D) 5σ/1π 
E) 6σ/0π 
A) 2σ/4π 
B) 3σ/3π 
C) 4σ/2π 
D) 5σ/1π 
E) 6σ/0π

Question 5

What would be the hybridization of the N in the benzene-like molecule (C5H5N)?

Accepted Answer

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

Question 6

According to VB theory,sigma bonds are:

Accepted Answer

A) always present in double bonds 
B) formed only by p orbitals 
C) formed only by hybrid orbitals 
D) formed only by s orbitals 
E) formed only by unhybridized orbitals 
A) always present in double bonds 
B) formed only by p orbitals 
C) formed only by hybrid orbitals 
D) formed only by s orbitals 
E) formed only by unhybridized orbitals

Question 7

According to the valence bond theory,in the ion NH4+,nitrogen is using which orbitals for bonding?

Accepted Answer

A) sp3  
B) p 
C) sp2d  
D) sp 
E) s 
A) sp3  
B) p 
C) sp2d  
D) sp 
E) s

Question 8

What is the molecular geometry of ClF4 -?

Accepted Answer

A) seesaw 
B) square planar 
C) square pyramidal 
D) tetrahedral 
A) seesaw 
B) square planar 
C) square pyramidal 
D) tetrahedral

Question 9

According to the molecular orbital (MO)theory,when two oxygen atoms bond together,their 2p orbitals combine to form:

Accepted Answer

A) two sigma molecular orbitals (MOs)and four pi MOs 
B) two sigma MOs and two pi MOs 
C) four pi MOs only 
D) one sigma and one pi MO 
E) a delocalized set of MO 
A) two sigma molecular orbitals (MOs)and four pi MOs 
B) two sigma MOs and two pi MOs 
C) four pi MOs only 
D) one sigma and one pi MO 
E) a delocalized set of MO

Question 10

The orbital hybridization on the carbon atoms in C2H2  is:

Accepted Answer

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

Question 11

Which of the pairs of molecules below have the same hybridization on the central atom? (The central atom is underlined. )

Accepted Answer

A) HOCl,ClF3  
B) H2O,HNO 
C) HCN,CO2  
D) BeH2,NH3  
E) H3COH,CH2O 
A) HOCl,ClF3  
B) H2O,HNO 
C) HCN,CO2  
D) BeH2,NH3  
E) H3COH,CH2O

Question 12

A σ bond:

Accepted Answer

A) can only be formed by s orbitals 
B) is weaker than a pi bond 
C) has high electron probability along the axis between atoms 
D) cannot be formed by two p orbitals 
E) is formed through side-on overlap of two atomic orbitals 
A) can only be formed by s orbitals 
B) is weaker than a pi bond 
C) has high electron probability along the axis between atoms 
D) cannot be formed by two p orbitals 
E) is formed through side-on overlap of two atomic orbitals

Question 13

The three molecular shapes an sp3 hybridized molecule can have are ________.

Accepted Answer

A) triangular,bent,T-shaped 
B) irregular tetrahedral,T-shaped,linear 
C) octahedral,square pyramidal,square planar 
D) tetrahedral,trigonal pyramidal,bent 
E) tetrahedral,T-shaped,bent 
A) triangular,bent,T-shaped 
B) irregular tetrahedral,T-shaped,linear 
C) octahedral,square pyramidal,square planar 
D) tetrahedral,trigonal pyramidal,bent 
E) tetrahedral,T-shaped,bent

Question 14

Find the correct statements about the bonding in methane,CH4.
I.The carbon s and p orbitals combine to form four equivalent sp3 orbitals
II.All C-H bonds have the same strength
III.Molecular geometry is different from electron group geometry
IV.Four C sp3 orbitals combine with the s orbitals of the hydrogens to form bonds

Accepted Answer

A) I,II,III 
B) I,II,IV 
C) II,II,IV 
D) I,III,IV 
E) I),II) 
A) I,II,III 
B) I,II,IV 
C) II,II,IV 
D) I,III,IV 
E) I),II)

Question 15

What is the molecular geometry of SF5-?

Accepted Answer

A) octahedral 
B) seesaw 
C) square pyramidal 
D) trigonal bipyramidal 
A) octahedral 
B) seesaw 
C) square pyramidal 
D) trigonal bipyramidal

Question 16

How would replacing one of benzene's C atoms and the H atom attached to it with an N atom (C5H5N)affect the delocalized electrons?

Accepted Answer

A) The molecule would not be stable. 
B) The N can have delocalized electrons like C. 
C) Only the five C atoms would be included in the delocalized electrons. 
D) There would be no delocalized electrons but a double bond between the N and a C. 
E) There would be no delocalized electrons but a double bond between the N and the C on each side of the N. 
A) The molecule would not be stable. 
B) The N can have delocalized electrons like C. 
C) Only the five C atoms would be included in the delocalized electrons. 
D) There would be no delocalized electrons but a double bond between the N and a C. 
E) There would be no delocalized electrons but a double bond between the N and the C on each side of the N.

Question 17

Resonance structures and delocalized orbitals are different ways to describe the same bonding.

Accepted Answer

A) True 
 B)False

Question 18

Using the VSEPR model,the electron-group geometry of the central atom in BF3 is:

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 19

Choose the INCORRECT statement about SnCl2.

Accepted Answer

A) The hybridization of Sn is sp2. 
B) The molecule is linear. 
C) There is one lone pair of electrons on Sn. 
D) There are no π bonds. 
E) There are two σ bonds. 
A) The hybridization of Sn is sp2. 
B) The molecule is linear. 
C) There is one lone pair of electrons on Sn. 
D) There are no π bonds. 
E) There are two σ bonds.

Question 20

Which of the following does NOT involve any delocalized π bonds?

Accepted Answer

A) acetate ion 
B) carbonate ion 
C) nitric acid 
D) nitrous acid 
E) ozone 
A) acetate ion 
B) carbonate ion 
C) nitric acid 
D) nitrous acid 
E) ozone

Exam 11: Chemical Bonding Ii: Valence Bond and Molecular Orbital Theories

How many σ- and π-bonds,respectively,are there in phenylisothiocyanate,C6H5NCS? Ignore the C-H bonds in your counting.

For the molecule

According to MO theory,all of the following have a bond order of 2 EXCEPT:

How many σ bonds and how many π bonds are present in the carbonic acid molecule,H2CO3?

What would be the hybridization of the N in the benzene-like molecule (C5H5N)?

According to VB theory,sigma bonds are:

According to the valence bond theory,in the ion NH4+,nitrogen is using which orbitals for bonding?

What is the molecular geometry of ClF4 -?

According to the molecular orbital (MO)theory,when two oxygen atoms bond together,their 2p orbitals combine to form:

The orbital hybridization on the carbon atoms in C2H2 is:

Which of the pairs of molecules below have the same hybridization on the central atom? (The central atom is underlined. )

A σ bond:

The three molecular shapes an sp3 hybridized molecule can have are ________.

What is the molecular geometry of SF5-?

How would replacing one of benzene's C atoms and the H atom attached to it with an N atom (C5H5N)affect the delocalized electrons?

Resonance structures and delocalized orbitals are different ways to describe the same bonding.

Using the VSEPR model,the electron-group geometry of the central atom in BF3 is:

Choose the INCORRECT statement about SnCl2.

Which of the following does NOT involve any delocalized π bonds?

Matter: Its Properties and Measurement

Atoms and the Atomic Theory

Chemical Compounds

Chemical Reactions

Introduction to Reactions in Aqueous Solutions

Gases

Thermochemistry

Electrons in Atoms

The Periodic Table and Some Atomic Properties

Chemical Bonding I: Basic Concepts

Intermolecular Forces: Liquids and Solids

Spontaneous Change: Entropy and Gibbs Energy

Solutions and Their Physical Properties

Principles of Chemical Equilibrium

Acids and Bases

Additional Aspects of Acidbase Equilibria

Solubility and Complex-Ion Equilibria

Electrochemistry

Chemical Kinetics

Chemistry of the Main-Group Elements I: Groups 1,2,13,and 14

Chemistry of the Main-Group Elements Ii: Groups 18,17,16,15,and Hydrogen

The Transition Elements

Complex Ions and Coordination Compounds

Nuclear Chemistry

Structures of Organic Compounds

Reactions of Organic Compounds

Chemistry of the Living State

Filters

How many σ- and π-bonds,respectively,are there in phenylisothiocyanate,C₆H₅NCS? Ignore the C-H bonds in your counting.

How many σ bonds and how many π bonds are present in the carbonic acid molecule,H₂CO₃?

What would be the hybridization of the N in the benzene-like molecule (C₅H₅N)?

According to the valence bond theory,in the ion NH₄⁺,nitrogen is using which orbitals for bonding?

What is the molecular geometry of ClF₄ ^-?

The orbital hybridization on the carbon atoms in C₂H₂ is:

The three molecular shapes an sp³ hybridized molecule can have are ________.

What is the molecular geometry of SF₅^-?

How would replacing one of benzene's C atoms and the H atom attached to it with an N atom (C₅H₅N)affect the delocalized electrons?

Using the VSEPR model,the electron-group geometry of the central atom in BF₃ is:

Choose the INCORRECT statement about SnCl₂.