Question 1

How many valence electrons surround the xenon atom in xenon tetrafluoride (XeF4)?

Accepted Answer

A) 8 
B) 4 
C) 10 
D) 12 
E) 6 
A) 8 
B) 4 
C) 10 
D) 12 
E) 6

Question 2

Indicate which one of the following does not contain a polar covalent bond.

Accepted Answer

A) I2 
B) CO 
C) HF 
D) NO 
E) CNF1F1F1S1F1F1F10 
A) I2 
B) CO 
C) HF 
D) NO 
E) CNF1F1F1S1F1F1F10

Question 3

Draw two reasonable Lewis structures for sulfurous acid, H2SO3. Identify the most stable form by using the concept of formal charges. Explain the reason for your choice.

Accepted Answer

@#IMG-DLM& Using the criterion of formal charge, t

Question 4

Acetonitrile (CH3CN) is an important industrial chemical. Among other things, it is used to make plastic moldings, which have multiple uses, from car parts to Lego bricks. Which one of the following statements about acetonitrile is not correct?

Accepted Answer

A) Acetonitrile has 16 valence electrons. 
B) Acetonitrile has one triple bond. 
C) Acetonitrile has one pair of nonbonding electrons. 
D) All atoms satisfy the octet rule in acetonitrile. 
E) One carbon atom and the nitrogen atom have nonzero formal charges. 
A) Acetonitrile has 16 valence electrons. 
B) Acetonitrile has one triple bond. 
C) Acetonitrile has one pair of nonbonding electrons. 
D) All atoms satisfy the octet rule in acetonitrile. 
E) One carbon atom and the nitrogen atom have nonzero formal charges.

Question 5

Chlorofluorocarbons (CFCs or freon) are linked to the depletion of atmospheric ozone. Draw the Lewis structure of Freon-1113, C2ClF3.

Accepted Answer

Question 6

Which of the following has the strongest bond? The number in parentheses is the bond length.

Accepted Answer

A) H-Br (141 pm) 
B) H-I (161 pm) 
C) H-Cl (127 pm) 
D) H-F (92 pm) 
E) H-S (134 pm) 
A) H-Br (141 pm) 
B) H-I (161 pm) 
C) H-Cl (127 pm) 
D) H-F (92 pm) 
E) H-S (134 pm)

Question 7

Which carbon-halogen bond is the most polar?

Accepted Answer

The answer of Which carbon-halogen bond is the most polar?...

Question 8

Resonance structures indicate that ________

Accepted Answer

A) there is more than one allotropic form of a compound. 
B) more than one ionic form of a compound exists. 
C) the electronic structure is an average or superposition of the diagrams. 
D) more than one isotopic form of an element exists in the molecule. 
E) the molecule jumps back and forth between two or more different electronic structures. 
A) there is more than one allotropic form of a compound. 
B) more than one ionic form of a compound exists. 
C) the electronic structure is an average or superposition of the diagrams. 
D) more than one isotopic form of an element exists in the molecule. 
E) the molecule jumps back and forth between two or more different electronic structures.

Question 9

In which of the following molecules does the central atom have an expanded octet?

Accepted Answer

A) N2O 
B) PCl5 
C) BeF2 
D) AsF3 
E) NO2 
A) N2O 
B) PCl5 
C) BeF2 
D) AsF3 
E) NO2

Question 10

How many valence electrons are there in BrOF1F1F1S1F1F1F10?

Accepted Answer

A) 7 
B) 6 
C) 13 
D) 14 
E) 18 
A) 7 
B) 6 
C) 13 
D) 14 
E) 18

Question 11

How many total equivalent Lewis structures are needed to describe the carbonate anion, CO32F1F1F1S1F1F1F10?

Accepted Answer

A) 1 
B) 2 
C) 3 
D) 4 
E) 5 
A) 1 
B) 2 
C) 3 
D) 4 
E) 5

Question 12

How many lone pairs are there in ClOF1F1F1S1F1F1F10?

Accepted Answer

A) 1 
B) 2 
C) 3 
D) 4 
E) 6 
A) 1 
B) 2 
C) 3 
D) 4 
E) 6

Question 13

Electronegativity increases from left to right across a period because of ________

Accepted Answer

A) increased shielding of valence electrons by the core electrons. 
B) an increase in the number of protons in the nucleus. 
C) a decrease in the effective nuclear charge (Zeff). 
D) an increase in the shielding of core electrons by the valence electrons. 
E) a decrease in the ionization potential. 
A) increased shielding of valence electrons by the core electrons. 
B) an increase in the number of protons in the nucleus. 
C) a decrease in the effective nuclear charge (Zeff). 
D) an increase in the shielding of core electrons by the valence electrons. 
E) a decrease in the ionization potential.

Question 14

The following Lewis symbol corresponds to which element?

Accepted Answer

A) Be 
B) B 
C) C 
D) N 
E) O 
A) Be 
B) B 
C) C 
D) N 
E) O

Question 15

Which one of the molecules below has 10 electrons around the central atom in a Lewis structure that has all atoms with a formal charge of zero?
I.POCl3
II. PF3
III. SO3
IV. SOF2

Accepted Answer

A) I only 
B) II only 
C) III only 
D) IV only 
E) both I and IV 
A) I only 
B) II only 
C) III only 
D) IV only 
E) both I and IV

Question 16

Based on electronegativities, which bond of the following bonds is the most polar and which is the least polar? HF1F1F1S1F1F1F10F, HF1F1F1S1F1F1F10N, HF1F1F1S1F1F1F10C, HF1F1F1S1F1F1F10H, and HF1F1F1S1F1F1F10O

Accepted Answer

HF1F1F1S1F1F1F10F i

Question 17

How many bonding electrons are assigned to the nitrogen in the Lewis structure of ammonia (NH3)?

Accepted Answer

A) 3 
B) 6 
C) 5 
D) 8 
E) 4 
A) 3 
B) 6 
C) 5 
D) 8 
E) 4

Question 18

Which of the following elements has 6 valence electrons?

Accepted Answer

A) C 
B) S 
C) N 
D) Br 
E) Be 
A) C 
B) S 
C) N 
D) Br 
E) Be

Question 19

Which of the following is most likely a polar covalent bond?

Accepted Answer

A) Na F1F1F1S1F1F1F10F1F1F1S1F1F1F10Cl 
B) H F1F1F1S1F1F1F10F1F1F1S1F1F1F10H 
C) C F1F1F1S1F1F1F10F1F1F1S1F1F1F10N 
D) K F1F1F1S1F1F1F10F1F1F1S1F1F1F10F 
E) Ca F1F1F1S1F1F1F10F1F1F1S1F1F1F10O 
A) Na F1F1F1S1F1F1F10F1F1F1S1F1F1F10Cl 
B) H F1F1F1S1F1F1F10F1F1F1S1F1F1F10H 
C) C F1F1F1S1F1F1F10F1F1F1S1F1F1F10N 
D) K F1F1F1S1F1F1F10F1F1F1S1F1F1F10F 
E) Ca F1F1F1S1F1F1F10F1F1F1S1F1F1F10O

Question 20

Which of the following represents the best Lewis structure for dinitrogen oxide?

Accepted Answer

A)    
B)    
C)    
D)    
E)    
A)    
B)    
C)    
D)    
E)

Exam 8: Chemical Bonds: What Makes a Gas a Greenhouse Gas

How many valence electrons surround the xenon atom in xenon tetrafluoride (XeF4)?

Indicate which one of the following does not contain a polar covalent bond.

Draw two reasonable Lewis structures for sulfurous acid, H2SO3. Identify the most stable form by using the concept of formal charges. Explain the reason for your choice.

Acetonitrile (CH3CN) is an important industrial chemical. Among other things, it is used to make plastic moldings, which have multiple uses, from car parts to Lego bricks. Which one of the following statements about acetonitrile is not correct?

Chlorofluorocarbons (CFCs or freon) are linked to the depletion of atmospheric ozone. Draw the Lewis structure of Freon-1113, C2ClF3.

Which of the following has the strongest bond? The number in parentheses is the bond length.

Which carbon-halogen bond is the most polar?

Resonance structures indicate that ________

In which of the following molecules does the central atom have an expanded octet?

How many valence electrons are there in BrO?

How many total equivalent Lewis structures are needed to describe the carbonate anion, CO32?

How many lone pairs are there in ClO?

Electronegativity increases from left to right across a period because of ________

The following Lewis symbol corresponds to which element?

Which one of the molecules below has 10 electrons around the central atom in a Lewis structure that has all atoms with a formal charge of zero? I.POCl3 II. PF3 III. SO3 IV. SOF2

Based on electronegativities, which bond of the following bonds is the most polar and which is the least polar? HF, HN, HC, HH, and HO

How many bonding electrons are assigned to the nitrogen in the Lewis structure of ammonia (NH3)?

Which of the following elements has 6 valence electrons?

Which of the following is most likely a polar covalent bond?

Which of the following represents the best Lewis structure for dinitrogen oxide?

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

Molecular Geometry: Shape Determines Function

Intermolecular Forces: The Uniqueness of Water

Solutions: Properties and Behavior

Solids: Crystals, Alloys, and Polymers

Chemical Kinetics: Reactions in the Atmosphere

Chemical Equilibrium: How Much Product Does a Reaction Really Make

Acidbase Equilibria: Proton Transfer in Biological Systems

Additional Aqueous Equilibria: Chemistry and the Oceans

Thermodynamics: Spontaneous and Nonspontaneous Reactions and Processes

Electrochemistry: The Quest for Clean Energy

Nuclear Chemistry: Applications to Energy and Medicine

Organic and Biological Molecules: the Compounds of Life

The Main Group Elements: Life and the Periodic Table

Transition Metals: Biological and Medical Applications

Filters

How many valence electrons surround the xenon atom in xenon tetrafluoride (XeF₄)?

Draw two reasonable Lewis structures for sulfurous acid, H₂SO₃. Identify the most stable form by using the concept of formal charges. Explain the reason for your choice.

Acetonitrile (CH₃CN) is an important industrial chemical. Among other things, it is used to make plastic moldings, which have multiple uses, from car parts to Lego bricks. Which one of the following statements about acetonitrile is not correct?

Chlorofluorocarbons (CFCs or freon) are linked to the depletion of atmospheric ozone. Draw the Lewis structure of Freon-1113, C₂ClF₃.

How many valence electrons are there in BrO^?

How many total equivalent Lewis structures are needed to describe the carbonate anion, CO₃²^?

How many lone pairs are there in ClO^?

Which one of the molecules below has 10 electrons around the central atom in a Lewis structure that has all atoms with a formal charge of zero? I.POCl₃ II. PF₃ III. SO₃ IV. SOF₂

How many bonding electrons are assigned to the nitrogen in the Lewis structure of ammonia (NH₃)?