Question 1

Given the electronegativities below, which covalent single bond is most polar? Element: H C N O
Electronegativity: 2.1 2.5 3.0 3.5

Accepted Answer

A) C-H 
B) N-H 
C) O-H 
D) O-C 
E) O-N 
A) C-H 
B) N-H 
C) O-H 
D) O-C 
E) O-N

Question 2

There are __________ unpaired electrons in the Lewis symbol for a (an)sodium ion.

Accepted Answer

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

Question 3

In the Lewis structure of ClF, the formal charge on Cl is __________ and the formal charge on F is __________.

Accepted Answer

A) -1, -1 
B) 0, 0 
C) 0, -1 
D) +1, -1 
E) -1, +1 
A) -1, -1 
B) 0, 0 
C) 0, -1 
D) +1, -1 
E) -1, +1

Question 4

The oxidation number of phosphorus in PF3 is __________.

Accepted Answer

A) -2 
B) +1 
C) +3 
D) +2 
E) -3 
A) -2 
B) +1 
C) +3 
D) +2 
E) -3

Question 5

The Lewis structure of N2H2 shows __________.

Accepted Answer

A) a nitrogen-nitrogen triple bond 
B) a nitrogen-nitrogen single bond 
C) each nitrogen has one nonbonding electron pair 
D) each nitrogen has two nonbonding electron pairs 
E) each hydrogen has one nonbonding electron pair 
A) a nitrogen-nitrogen triple bond 
B) a nitrogen-nitrogen single bond 
C) each nitrogen has one nonbonding electron pair 
D) each nitrogen has two nonbonding electron pairs 
E) each hydrogen has one nonbonding electron pair

Question 6

What is the electron configuration for the Fe2+ ion?

Accepted Answer

A) [Ar]4s03d6 
B) [Ar]4s23d4 
C) [Ar]4s03d8 
D) [Ar]4s23d8 
E) [Ar]4s63d2 
A) [Ar]4s03d6 
B) [Ar]4s23d4 
C) [Ar]4s03d8 
D) [Ar]4s23d8 
E) [Ar]4s63d2

Question 7

Using the table of bond dissociation energies, the ΔH for the following gas-phase reaction is __________ kJ.

Accepted Answer

A) 291 
B) 2017 
C) -57 
D) -356 
E) -291 
A) 291 
B) 2017 
C) -57 
D) -356 
E) -291

Question 8

Of the bonds C-N, C-N, and C≡N, the C-N bond is __________.

Accepted Answer

A) strongest/shortest 
B) strongest/longest 
C) weakest/shortest 
D) weakest/longest 
E) intermediate in both strength and length 
A) strongest/shortest 
B) strongest/longest 
C) weakest/shortest 
D) weakest/longest 
E) intermediate in both strength and length

Question 9

In the Lewis structure of HCO3-, the formal charge on H is __________ and the formal charge on C is __________.

Accepted Answer

A) -1, -1 
B) 0, 0 
C) 0, -1 
D) +1, -1 
E) -1, +1 
A) -1, -1 
B) 0, 0 
C) 0, -1 
D) +1, -1 
E) -1, +1

Question 10

Of the bonds below, __________ is the least polar.

Accepted Answer

A) C, O 
B) N, O 
C) C, F 
D) S, O 
E) K, Br 
A) C, O 
B) N, O 
C) C, F 
D) S, O 
E) K, Br

Question 11

A valid Lewis structure of __________ cannot be drawn without violating the octet rule.

Accepted Answer

A) NI3 
B) SO2 
C) ICl5 
D) SiF4 
E) CO2 
A) NI3 
B) SO2 
C) ICl5 
D) SiF4 
E) CO2

Question 12

Using the table of bond dissociation energies, the ΔH for the following gas-phase reaction is __________ kJ.

Accepted Answer

A) -44 
B) 38 
C) 304 
D) 2134 
E) -38 
A) -44 
B) 38 
C) 304 
D) 2134 
E) -38

Question 13

Which of the following would have to gain two electrons in order to achieve a noble gas electron configuration? O Sr Na Se Br

Accepted Answer

A) Br 
B) Sr 
C) Na 
D) O, Se 
E) Sr, O, Se 
A) Br 
B) Sr 
C) Na 
D) O, Se 
E) Sr, O, Se

Question 14

Of the bonds C-C, C-C, and C≡C, the C-C bond is __________.

Accepted Answer

A) strongest/shortest 
B) strongest/longest 
C) weakest/longest 
D) weakest/shortest 
E) intermediate in both strength and length 
A) strongest/shortest 
B) strongest/longest 
C) weakest/longest 
D) weakest/shortest 
E) intermediate in both strength and length

Question 15

Which halogen, bromine or iodine, will form the more polar bond with phosphorus?

Accepted Answer

The answer of Which halogen, bromine or iodine, will form...

Question 16

Using the table of average bond energies below, the ΔH for the reaction is __________ kJ.   Bond: C≡C C-C H-I C-I C-H D (kJ/mol): 839 348 299 240 413

Accepted Answer

A) +160 
B) -160 
C) -217 
D) -63 
E) +63 
A) +160 
B) -160 
C) -217 
D) -63 
E) +63

Question 17

To produce maximum heat, an explosive compound should have __________ chemical bonds and decompose to molecule with __________ bonds.

Accepted Answer

The answer of To produce maximum heat, an explosive compound...

Question 18

The formal charge on sulfur in SO42- is __________, where the Lewis structure of the ion is:

Accepted Answer

A) -2 
B) 0 
C) +2 
D) +4 
E) -4 
A) -2 
B) 0 
C) +2 
D) +4 
E) -4

Question 19

Based on the octet rule, magnesium most likely forms a __________ ion.

Accepted Answer

A) Mg2+ 
B) Mg2- 
C) Mg6- 
D) Mg6+ 
E) Mg- 
A) Mg2+ 
B) Mg2- 
C) Mg6- 
D) Mg6+ 
E) Mg-

Question 20

For resonance forms of a molecule or ion, __________.

Accepted Answer

A) one always corresponds to the observed structure 
B) all the resonance structures are observed in various proportions 
C) the observed structure is an average of the resonance forms 
D) the same atoms need not be bonded to each other in all resonance forms 
E) there cannot be more than two resonance structures for a given species 
A) one always corresponds to the observed structure 
B) all the resonance structures are observed in various proportions 
C) the observed structure is an average of the resonance forms 
D) the same atoms need not be bonded to each other in all resonance forms 
E) there cannot be more than two resonance structures for a given species

Exam 8: Basic Concepts of Chemical Bonding

Given the electronegativities below, which covalent single bond is most polar? Element: H C N O Electronegativity: 2.1 2.5 3.0 3.5

There are __________ unpaired electrons in the Lewis symbol for a (an)sodium ion.

In the Lewis structure of ClF, the formal charge on Cl is __________ and the formal charge on F is __________.

The oxidation number of phosphorus in PF3 is __________.

The Lewis structure of N2H2 shows __________.

What is the electron configuration for the Fe2+ ion?

Using the table of bond dissociation energies, the ΔH for the following gas-phase reaction is __________ kJ.

Of the bonds C-N, C-N, and C≡N, the C-N bond is __________.

In the Lewis structure of HCO3-, the formal charge on H is __________ and the formal charge on C is __________.

Of the bonds below, __________ is the least polar.

A valid Lewis structure of __________ cannot be drawn without violating the octet rule.

Using the table of bond dissociation energies, the ΔH for the following gas-phase reaction is __________ kJ.

Which of the following would have to gain two electrons in order to achieve a noble gas electron configuration? O Sr Na Se Br

Of the bonds C-C, C-C, and C≡C, the C-C bond is __________.

Which halogen, bromine or iodine, will form the more polar bond with phosphorus?

Using the table of average bond energies below, the ΔH for the reaction is __________ kJ. Bond: C≡C C-C H-I C-I C-H D (kJ/mol): 839 348 299 240 413

To produce maximum heat, an explosive compound should have __________ chemical bonds and decompose to molecule with __________ bonds.

The formal charge on sulfur in SO42- is __________, where the Lewis structure of the ion is:

Based on the octet rule, magnesium most likely forms a __________ ion.

For resonance forms of a molecule or ion, __________.

Introduction: Matter and Measurement

Atoms, Molecules, and Ions

Stoichiometry: Calculations With Chemical Formulas and Equations

Aqueous Reactions and Solution Stoichiometry

Thermochemistry

Electronic Structure of Atoms

Periodic Properties of the Elements

Molecular Geometry and Bonding Theories

Gases

Liquids and Intermolecular Forces

Solids and Modern Materials

Properties of Solutions

Chemical Kinetics

Chemical Equilibrium

Acid-Base Equilibria

Additional Aspects of Aqueous Equilibria

Chemistry of the Environment

Chemical Thermodynamics

Electrochemistry

Nuclear Chemistry

Chemistry of the Nonmetals

Transition Metals and Coordination Chemistry

The Chemistry of Life: Organic and Biological Chemistry

Filters

In the Lewis structure of ClF, the formal charge on Cl is and the formal charge on F is .

The oxidation number of phosphorus in PF₃ is __________.

The Lewis structure of N₂H₂ shows __________.

What is the electron configuration for the Fe²⁺ ion?

In the Lewis structure of HCO₃^-, the formal charge on H is and the formal charge on C is .

To produce maximum heat, an explosive compound should have chemical bonds and decompose to molecule with bonds.

The formal charge on sulfur in SO₄^2- is __________, where the Lewis structure of the ion is: