Question 1

Which of the following molecules has both an electron group geometry and a molecular geometry described as trigonal planar?

Accepted Answer

A)  SiH4 
B)  PF3 
C)  OF2 
D)  CHF3 
E)  BF3 
A)  SiH4 
B)  PF3 
C)  OF2 
D)  CHF3 
E)  BF3 E

Question 2

A chemical bond for which one of the bonded atoms provides both electrons for the bond is referred to as a:

Accepted Answer

A)  double covalent bond 
B)  coordinate covalent bond 
C)  formal covalent bond 
D)  free radical bond 
E)  VSEPR bond 
A)  double covalent bond 
B)  coordinate covalent bond 
C)  formal covalent bond 
D)  free radical bond 
E)  VSEPR bond B

Question 3

Given the bond enthalpies N-H (389), Cl-Cl (243), N-Cl (201), and H-Cl (431) in kJ/mol, compute ΔH° in kJ/mol for NH3(g) + Cl2(g) → NH2Cl + HCl(g)

Accepted Answer

A)  -393 
B)  -1100 
C)  +71 
D)  +393 
E)  0 
A)  -393 
B)  -1100 
C)  +71 
D)  +393 
E)  0 E

Question 4

Which of the following species has a pyramidal structure?

Accepted Answer

A)  ClO3- 
B)  ClO4- 
C)  ClO2- 
D)  ClO2 
A)  ClO3- 
B)  ClO4- 
C)  ClO2- 
D)  ClO2

Question 5

Choose the INCORRECT statement.

Accepted Answer

A)  A Lewis symbol consists of a chemical symbol and the outer shell electrons. 
B)  In a Lewis symbol, the chemical symbol represents the nucleus of the atom. 
C)  A Lewis structure is a combination of Lewis symbols that represent the transfer or sharing of electrons in a chemical bond. 
D)  An ion written as a Lewis symbol has brackets outside the electrons. 
E)  An ion written as a Lewis symbol has the charge written as a superscript outside the closing bracket. 
A)  A Lewis symbol consists of a chemical symbol and the outer shell electrons. 
B)  In a Lewis symbol, the chemical symbol represents the nucleus of the atom. 
C)  A Lewis structure is a combination of Lewis symbols that represent the transfer or sharing of electrons in a chemical bond. 
D)  An ion written as a Lewis symbol has brackets outside the electrons. 
E)  An ion written as a Lewis symbol has the charge written as a superscript outside the closing bracket.

Question 6

How many "dots" should be shown for the oxygen symbol in lithium oxide?

Accepted Answer

A)  2 
B)  4 
C)  6 
D)  8 
E)  10 
A)  2 
B)  4 
C)  6 
D)  8 
E)  10

Question 7

With the representations of "I" for ionic bond, "PC" for polar covalent bond, and "NP" for nonpolar covalent bond, which of the following descriptive combinations is correct?

Accepted Answer

A)  CsF/PC 
B)  F2/I 
C)  NO/NP 
D)  HCl/PC 
E)  BrCl/NP 
A)  CsF/PC 
B)  F2/I 
C)  NO/NP 
D)  HCl/PC 
E)  BrCl/NP

Question 8

What is the bond order for the carbon-oxygen bond in formaldehyde (CH2O), which has no O-H bonds?

Accepted Answer

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

Question 9

What is the molecular shape of BrF5?

Accepted Answer

A)  linear 
B)  square pyramid 
C)  square planar 
D)  octahedral 
E)  trigonal bipyramid 
A)  linear 
B)  square pyramid 
C)  square planar 
D)  octahedral 
E)  trigonal bipyramid

Question 10

Choose the INCORRECT statement.

Accepted Answer

A)  In a Lewis structure, a terminal atom is bonded to two or more atoms. 
B)  In a Lewis structure all valence electrons must appear. 
C)  In a Lewis structure, usually all electrons are paired. 
D)  In a Lewis structure, usually each atom acquires an outer-shell octet of electrons; H has 2 outer shell electrons. 
E)  In Lewis structures, most multiple covalent bonds are formed by C, N, O, P, and S. 
A)  In a Lewis structure, a terminal atom is bonded to two or more atoms. 
B)  In a Lewis structure all valence electrons must appear. 
C)  In a Lewis structure, usually all electrons are paired. 
D)  In a Lewis structure, usually each atom acquires an outer-shell octet of electrons; H has 2 outer shell electrons. 
E)  In Lewis structures, most multiple covalent bonds are formed by C, N, O, P, and S.

Question 11

Which of the following species exhibits resonance?

Accepted Answer

A)  OF2 
B)  ClO3- 
C)  N2 
D)  PCl5 
E)  BrF3 
A)  OF2 
B)  ClO3- 
C)  N2 
D)  PCl5 
E)  BrF3

Question 12

After drawing the Lewis dot structure for BeCl2, determine the number of single bonds, double bonds, and lone pairs on the central atom.

Accepted Answer

A)  2, 0, 0 
B)  2, 0, 2 
C)  2, 0,1 
D)  0, 2, 0 
E)  1, 1, 0 
A)  2, 0, 0 
B)  2, 0, 2 
C)  2, 0,1 
D)  0, 2, 0 
E)  1, 1, 0

Question 13

Which of the following species is best represented by a resonance hybrid having two contributing structures?

Accepted Answer

A)  nitric acid 
B)  nitrous acid 
C)  nitride ion 
D)  nitrate ion 
E)  nitrogen 
A)  nitric acid 
B)  nitrous acid 
C)  nitride ion 
D)  nitrate ion 
E)  nitrogen

Question 14

Which chloride should have the greatest covalent character?

Accepted Answer

A)  NaCl 
B)  BeCl2 
C)  KCl 
D)  BaCl2 
E)  CaCl2 
A)  NaCl 
B)  BeCl2 
C)  KCl 
D)  BaCl2 
E)  CaCl2

Question 15

Given the listed average bond energies, calculate the enthalpy change for the production of 48 g of methanol by the reaction: CO2(g) + 3 H2(g) → CH3OH(g) + H2O(g)
C-O/360 kJ/mol C=O/736 kJ/mol H-H/436 kJ/mol
H-O/464 kJ/mol H-C/414 kJ/mol

Accepted Answer

A)  +214 kJ 
B)  +639 kJ 
C)  0 
D)  -214 kJ 
E)  -108 kJ 
A)  +214 kJ 
B)  +639 kJ 
C)  0 
D)  -214 kJ 
E)  -108 kJ

Question 16

What is the correct molecular geometry for the carbon atom in urea (NH2)2CO?

Accepted Answer

A)  Tetrahedral 
B)  T-Shaped 
C)  Trigonal planar 
D)  Trigonal pyramidal 
E)  Trigonal bipyramidal 
A)  Tetrahedral 
B)  T-Shaped 
C)  Trigonal planar 
D)  Trigonal pyramidal 
E)  Trigonal bipyramidal

Question 17

After drawing the Lewis dot structure for XeCl2, determine the number of single bonds, double bonds, and lone pairs on the central atom.

Accepted Answer

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

Question 18

Given the bond enthalpies N≡N (946), H-H (436), H-N (389), all in kJ/mol, estimate ΔH for the following reaction: N2(g) + 3 H2(g) → 2NH3(g).

Accepted Answer

A)  -215 kJ 
B)  -863 kJ 
C)  -80 kJ 
D)  568 kJ 
E)  -1476 kJ 
A)  -215 kJ 
B)  -863 kJ 
C)  -80 kJ 
D)  568 kJ 
E)  -1476 kJ

Question 19

Choose the INCORRECT statement.

Accepted Answer

A)  In a Lewis structure, a covalent bond can be represented by a pair of electrons or a dash. 
B)  Pairs of electrons not involved in bonding are called lone pairs. 
C)  A molecule of two atoms is called a diatomic molecule. 
D)  Two electrons involved in a bond produce a double bond. 
E)  Three electron pairs involved in a bond produce a triple bond. 
A)  In a Lewis structure, a covalent bond can be represented by a pair of electrons or a dash. 
B)  Pairs of electrons not involved in bonding are called lone pairs. 
C)  A molecule of two atoms is called a diatomic molecule. 
D)  Two electrons involved in a bond produce a double bond. 
E)  Three electron pairs involved in a bond produce a triple bond.

Question 20

Given the following bond lengths in pm: C-C, 154; C = C, 134; Cl - Cl, 199 What is the best estimate of the C-Cl bond length in CCl4 in pm?

Accepted Answer

A)  353 pm 
B)  706 pm 
C)  167 pm 
D)  333 pm 
E)  177 pm 
A)  353 pm 
B)  706 pm 
C)  167 pm 
D)  333 pm 
E)  177 pm

Exam 10: Chemical Bonding I: Basic Concepts

Which of the following molecules has both an electron group geometry and a molecular geometry described as trigonal planar?

A chemical bond for which one of the bonded atoms provides both electrons for the bond is referred to as a:

Given the bond enthalpies N-H (389), Cl-Cl (243), N-Cl (201), and H-Cl (431) in kJ/mol, compute ΔH° in kJ/mol for NH3(g) + Cl2(g) → NH2Cl + HCl(g)

Which of the following species has a pyramidal structure?

Choose the INCORRECT statement.

How many "dots" should be shown for the oxygen symbol in lithium oxide?

With the representations of "I" for ionic bond, "PC" for polar covalent bond, and "NP" for nonpolar covalent bond, which of the following descriptive combinations is correct?

What is the bond order for the carbon-oxygen bond in formaldehyde (CH2O), which has no O-H bonds?

What is the molecular shape of BrF5?

Choose the INCORRECT statement.

Which of the following species exhibits resonance?

After drawing the Lewis dot structure for BeCl2, determine the number of single bonds, double bonds, and lone pairs on the central atom.

Which of the following species is best represented by a resonance hybrid having two contributing structures?

Which chloride should have the greatest covalent character?

Given the listed average bond energies, calculate the enthalpy change for the production of 48 g of methanol by the reaction: CO2(g) + 3 H2(g) → CH3OH(g) + H2O(g) C-O/360 kJ/mol C=O/736 kJ/mol H-H/436 kJ/mol H-O/464 kJ/mol H-C/414 kJ/mol

What is the correct molecular geometry for the carbon atom in urea (NH2)2CO?

After drawing the Lewis dot structure for XeCl2, determine the number of single bonds, double bonds, and lone pairs on the central atom.

Given the bond enthalpies N≡N (946), H-H (436), H-N (389), all in kJ/mol, estimate ΔH for the following reaction: N2(g) + 3 H2(g) → 2NH3(g).

Choose the INCORRECT statement.

Given the following bond lengths in pm: C-C, 154; C = C, 134; Cl - Cl, 199 What is the best estimate of the C-Cl bond length in CCl4 in pm?

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 II: Additional Aspects

Intermolecular Forces: Liquids and Solids

Solutions and Their Physical Properties

Chemical Kinetics

Principles of Chemical Equilibrium

Acids and Bases

Additional Aspects of Acid-Base Equilibria

Solubility and Complex-Ion Equilibria

Spontaneous Change: Entropy and Free Energy

Electrochemistry

Main Group Elements I: Groups 1, 2, 13, and 14

Main Group Elements II: Groups 18, 17, 16, 15, and Hydrogen

The Transition Elements

Complex Ions and Coordination Compounds

Nuclear Chemistry 1-41

Structures of Organic Compounds

Reactions of Organic Compounds

Chemistry of the Living State

Filters

Given the bond enthalpies N-H (389), Cl-Cl (243), N-Cl (201), and H-Cl (431) in kJ/mol, compute ΔH° in kJ/mol for NH₃(g) + Cl₂(g) → NH₂Cl + HCl(g)

What is the bond order for the carbon-oxygen bond in formaldehyde (CH₂O), which has no O-H bonds?

After drawing the Lewis dot structure for BeCl₂, determine the number of single bonds, double bonds, and lone pairs on the central atom.

Given the listed average bond energies, calculate the enthalpy change for the production of 48 g of methanol by the reaction: CO₂(g) + 3 H₂(g) → CH₃OH(g) + H₂O(g) C-O/360 kJ/mol C=O/736 kJ/mol H-H/436 kJ/mol H-O/464 kJ/mol H-C/414 kJ/mol

What is the correct molecular geometry for the carbon atom in urea (NH₂)₂CO?

After drawing the Lewis dot structure for XeCl₂, determine the number of single bonds, double bonds, and lone pairs on the central atom.

Given the bond enthalpies N≡N (946), H-H (436), H-N (389), all in kJ/mol, estimate ΔH for the following reaction: N₂(g) + 3 H₂(g) → 2NH₃(g).

Given the following bond lengths in pm: C-C, 154; C = C, 134; Cl - Cl, 199 What is the best estimate of the C-Cl bond length in CCl₄ in pm?