Question 1

Consider this structure:
   1. The longest bond is ________________.
2. The shortest of the carbon-carbon bonds is ________________.

Accepted Answer

1. e
2. c

Question 2

The lactate ion is a resonance hybrid:
   ​
1. Considering only the labeled bonds, the longest carbon-oxygen bond in the lactate ion is ________________.
2. Considering only the labeled bonds, the two bonds that have the same length are ________________ and ________________.

Accepted Answer

1. b
2. d; e

Question 3

Which statement is true about molecular orbitals of any given molecule?

Accepted Answer

A)  A bonding molecular orbital has higher energy and fewer nodes than an antibonding molecular orbital. 
B)  A bonding molecular orbital can have the same energy as an antibonding orbital. 
C)  Any antibonding orbital is never populated with electrons. 
D)  Any bonding molecular orbital always contains two electrons. 
E)  None of these is true. 
A)  A bonding molecular orbital has higher energy and fewer nodes than an antibonding molecular orbital. 
B)  A bonding molecular orbital can have the same energy as an antibonding orbital. 
C)  Any antibonding orbital is never populated with electrons. 
D)  Any bonding molecular orbital always contains two electrons. 
E)  None of these is true. E

Question 4

The occupied valence orbitals of the chlorine atom are

Accepted Answer

A)  2s and 2p. 
B)  3s. 
C)  3s and 3p. 
D)  3s and 3p and 3d. 
E)  4s and 4p. 
A)  2s and 2p. 
B)  3s. 
C)  3s and 3p. 
D)  3s and 3p and 3d. 
E)  4s and 4p.

Question 5

Of the bonds marked, which bond is the shortest?

Accepted Answer

The answer of Of the bonds marked, which bond is...

Question 6

Which one of the following statements about the hydrogen molecule cation, H2+ , is true?

Accepted Answer

A)  This cation is unstable because it does not have two electrons in a bonding molecular orbital. 
B)  The H-H bond in this cation is stronger than the H-H bond in the dihydrogen molecule H2. 
C)  This cation has one electron in the bonding molecular orbital and one electron in an antibonding molecular orbital. 
D)  This cation is stable relative to a hydrogen atom and a proton (H+). 
A)  This cation is unstable because it does not have two electrons in a bonding molecular orbital. 
B)  The H-H bond in this cation is stronger than the H-H bond in the dihydrogen molecule H2. 
C)  This cation has one electron in the bonding molecular orbital and one electron in an antibonding molecular orbital. 
D)  This cation is stable relative to a hydrogen atom and a proton (H+).

Question 7

What is the formal charge on carbon in this structure? All unshared electrons are shown.

Accepted Answer

The answer of What is the formal charge on carbon...

Question 8

In the resonance structures for methyl azide, all unshared electron pairs are indicated. Complete the structures by adding the missing formal charges.

Accepted Answer

The answer of In the resonance structures for methyl azide,...

Question 9

Select the two statements that are true.

Accepted Answer

A)  All polar molecules have a significant dipole moment. 
B)  All molecules containing polar bonds are polar molecules. 
C)  The polarity of a bond is accurately indicated in every case by the formal charges of the atoms involved in the bond. 
D)  All polar molecules contain one or more polar bonds. 
A)  All polar molecules have a significant dipole moment. 
B)  All molecules containing polar bonds are polar molecules. 
C)  The polarity of a bond is accurately indicated in every case by the formal charges of the atoms involved in the bond. 
D)  All polar molecules contain one or more polar bonds.

Question 10

According to molecular orbital theory, which one of these species does not exist?

Accepted Answer

A)  
 $$\mathrm { He } _ { 2 } ^ { + }$$ 
B)  
 $$\mathrm { H } _ { 2 } ^ { + }$$ 
C)  
 $$\mathrm { H } _ { 2 } ^ { - }$$ 
D)  
 $$\mathrm { H } _ { 2 } ^ { 2 - }$$ 
E)  CH4 
A)  
 $$\mathrm { He } _ { 2 } ^ { + }$$ 
B)  
 $$\mathrm { H } _ { 2 } ^ { + }$$ 
C)  
 $$\mathrm { H } _ { 2 } ^ { - }$$ 
D)  
 $$\mathrm { H } _ { 2 } ^ { 2 - }$$ 
E)  CH4

Question 11

The atomic orbital that cannot exist is

Accepted Answer

A)  1s. 
B)  1p. 
C)  2s. 
D)  2p. 
E)  3df. 
All can exist. 
A)  1s. 
B)  1p. 
C)  2s. 
D)  2p. 
E)  3df. 
All can exist.

Question 12

How many valence electrons does aluminum (Al, atomic number = 13) have?

Accepted Answer

The answer of How many valence electrons does aluminum (Al,...

Question 13

Identify the true statement(s) about molecular orbitals (MOs).

Accepted Answer

A)  Antibonding MOs always have more nodes than bonding orbitals. 
B)  Antibonding MOs always have higher energy than bonding MOs. 
C)  All bonding MOs have zero nodes. 
A)  Antibonding MOs always have more nodes than bonding orbitals. 
B)  Antibonding MOs always have higher energy than bonding MOs. 
C)  All bonding MOs have zero nodes.

Question 14

Consider this structure:
$$\mathrm { H } _ { 3 } \mathrm { C } \stackrel { a } { - } \mathrm { C } \stackrel { b } { \equiv } \mathrm { C } \stackrel { c } { - } \mathrm { CH } \stackrel { d } { = } \mathrm { CH } \stackrel { e } { - } \mathrm { CH } _ { 2 } \stackrel { f } { - } \mathrm { CH } _ { 3 }$$ The bond angle between bonds c and d is approximately

Accepted Answer

A)  109.5°. 
B)  120°. 
C)  60°. 
D)  180° 
A)  109.5°. 
B)  120°. 
C)  60°. 
D)  180°

Question 15

Complete the electron configuration diagram below for the element boron (B, atomic number = 5), showing 1s, 2s, 2px, 2py, and 2pz orbitals, their relative energies, and their electron populations indicated by "spin arrows" ↑ and ↓.

Accepted Answer

The answer of Complete the electron configuration diagram below for...

Question 16

What is the geometry of the borohydride ion, -BH4?

Accepted Answer

Question 17

Complete the structure for the cyanate ion by adding unshared electron pairs and formal charges. Every atom has an octet, and the overall charge on the ion is −1.
   ​

Accepted Answer

The answer of Complete the structure for the cyanate ion...

Question 18

Given that the acetate anion has the these equally important resonance structures, what is the bond order of each carbon-oxygen bond?

Accepted Answer

A)  The bond order of all carbon-oxygen bonds is ⅓. 
B)  The bond order of all carbon-oxygen bonds is ½. 
C)  The bond order of all carbon-oxygen bonds is 1.0. 
D)  The bond order of all carbon-oxygen bonds is 1.5. 
E)  The bond order of one carbon-oxygen bond is 1.0, and the bond order of the other carbon-oxygen is ½.f. 
The bond order of all carbon-oxygen bonds is 2.0. 
A)  The bond order of all carbon-oxygen bonds is ⅓. 
B)  The bond order of all carbon-oxygen bonds is ½. 
C)  The bond order of all carbon-oxygen bonds is 1.0. 
D)  The bond order of all carbon-oxygen bonds is 1.5. 
E)  The bond order of one carbon-oxygen bond is 1.0, and the bond order of the other carbon-oxygen is ½.f. 
The bond order of all carbon-oxygen bonds is 2.0.

Question 19

Add valence electrons to the structures so that the formal charge is properly accounted for. Assume that all atoms have no more electrons than allowed by the octet rule. Make your "electron dots" bold enough to be unambiguous.

Accepted Answer

The answer of Add valence electrons to the structures so...

Question 20

Which compound has the largest dipole moment?

Accepted Answer

A)  Compound A 
B)  Compound B 
C)  Compound C 
D)  Compound D 
A)  Compound A 
B)  Compound B 
C)  Compound C 
D)  Compound D

Exam 1: Chemical Bonding and Chemical Structure

Consider this structure: 1. The longest bond is ________________. 2. The shortest of the carbon-carbon bonds is ________________.

The lactate ion is a resonance hybrid: ​ 1. Considering only the labeled bonds, the longest carbon-oxygen bond in the lactate ion is ________________. 2. Considering only the labeled bonds, the two bonds that have the same length are ________________ and ________________.

Which statement is true about molecular orbitals of any given molecule?

The occupied valence orbitals of the chlorine atom are

Of the bonds marked, which bond is the shortest?

Which one of the following statements about the hydrogen molecule cation, H2+ , is true?

What is the formal charge on carbon in this structure? All unshared electrons are shown.

In the resonance structures for methyl azide, all unshared electron pairs are indicated. Complete the structures by adding the missing formal charges.

Select the two statements that are true.

According to molecular orbital theory, which one of these species does not exist?

The atomic orbital that cannot exist is

How many valence electrons does aluminum (Al, atomic number = 13) have?

Identify the true statement(s) about molecular orbitals (MOs).

Complete the electron configuration diagram below for the element boron (B, atomic number = 5), showing 1s, 2s, 2px, 2py, and 2pz orbitals, their relative energies, and their electron populations indicated by "spin arrows" ↑ and ↓.

What is the geometry of the borohydride ion, -BH4?

Complete the structure for the cyanate ion by adding unshared electron pairs and formal charges. Every atom has an octet, and the overall charge on the ion is −1. ​

Given that the acetate anion has the these equally important resonance structures, what is the bond order of each carbon-oxygen bond?

Add valence electrons to the structures so that the formal charge is properly accounted for. Assume that all atoms have no more electrons than allowed by the octet rule. Make your "electron dots" bold enough to be unambiguous.

Which compound has the largest dipole moment?

Alkanes and Organic Nomenclature

The Curved-Arrow Notation, Resonance, Acids and Bases, and Chemical Equilibrium

Introduction to Alkenes and Alkynes

Addition Reactions of Alkenes and Alkynes

Principles of Stereochemistry

Cyclic Compounds and Reaction Stereochemistry

Nomenclature and Noncovalent Intermolecular Interactions

The Chemistry of Alkyl Halides

Free-Radical Reactions, Main-Group Organometallic Compounds, and Carbenes

The Chemistry of Alcohols and Thiols

The Chemistry of Ethers, Epoxides, Glycols, and Sulfides

Introduction to Spectroscopy

Nuclear Magnetic Resonance Spectroscopy

Dienes and Aromaticity

The Chemistry of Benzene and Its Derivatives

Allylic and Benzylic Reactivity

The Chemistry of Aryl Halides, Vinylic Halides, and Phenols

The Chemistry of Aldehydes and Ketones

The Chemistry of Carboxylic Acids

The Chemistry of Carboxylic Acid Derivatives

The Chemistry of Enolate Ions, Enols, and Α,β-Unsaturated Carbonyl Compounds

The Chemistry of Amines

Carbohydrates

The Chemistry of Thioesters, Phosphate Esters, and Phosphate Anhydrides

The Chemistry of the Aromatic Heterocycles and Nucleic Acids

Amino Acids, Peptides, and Proteins

Pericyclic Reactions

Filters

Consider this structure: 1. The longest bond is . 2. The shortest of the carbon-carbon bonds is .

The lactate ion is a resonance hybrid: 1. Considering only the labeled bonds, the longest carbon-oxygen bond in the lactate ion is . 2. Considering only the labeled bonds, the two bonds that have the same length are and .

Which one of the following statements about the hydrogen molecule cation, H₂⁺ , is true?

What is the geometry of the borohydride ion, ^-BH₄?

Complete the structure for the cyanate ion by adding unshared electron pairs and formal charges. Every atom has an octet, and the overall charge on the ion is −1.