Question 1

The carbon atoms in the molecule below are labeled 1-8.Which CF1F1F1S1F1F1F10CF1F1F1S1F1F1F10F1F1F1S1F1F1F10C bond angle in the molecule would be approximately 120°?

Accepted Answer

A)  C1-C2-C3
B)  C2-C3-C4
C)  C4-C5-C6
D)  C5-C6-C7
E)  C6-C7-C8 B

Question 2

What are the approximate HF1F1F1S1F1F1F10CF1F1F1S1F1F1F10H bond angles expected for the carbanion whose structure is given in the ball-and-stick representation below?

Accepted Answer

A)  180°
B)  150°
C)  109.5°
D)  107°
E)  90° D

Question 3

Why do polar aprotic solvents solvate cations more strongly than anions? Using sodium chloride as the representative ionic compound,diagram the intermolecular interactions with tetrahydrofuran (THF).

Accepted Answer

Polar aprotic solvents often have a partially negative oxygen atom,or another heteroatom,that is attracted to the cation's positive charge.The anion-in this case,chloride-is not solvated as strongly due to either steric repulsions of hydrocarbon groups or the weaker induced dipole polarization of hydrocarbons.An example of THF interacting with NaCl is given here.

Question 4

Winter gasoline mixes for cold climates require 10% ethanol,or 1 gallon of ethanol for every
9 gallons of gasoline,in part to help prevent water in the gas from freezing and causing engine trouble.Diagram the intermolecular forces between water and ethanol,and between ethanol and octane.Why are the intermolecular forces relevant in winter mix gasoline?

Accepted Answer

The answer of Winter gasoline mixes for cold climates require...

Question 5

Explain why polar protic solvents (like butanol)solvate anions (like chloride)better than polar aprotic solvents (like N,N-dimethylformamide,DMF)do.

Accepted Answer

The answer of Explain why polar protic solvents (like butanol)solvate...

Question 6

A reverse micelle can form when a polar substance dissolves in a nonpolar substance.Create a conceptual diagram of a reverse micelle.What intermolecular forces are driving the formation of the reverse micelle?

Accepted Answer

The answer of A reverse micelle can form when a...

Question 7

(a) Group I cations are common ions found in organic salts.Write the electron configuration for the Group I cations below.In the fourth column,use circles to represent the relative size of each cation conceptually.Define the term ionic radius and label the ionic radius of each cation.
  
(b) Organic molecules called crown ethers (refer to the box titled "Phase Transfer Catalysts" in Chapter 2 of your text)can sequester a cation of specific size to make the organic anion more reactive.Charles Pedersen,in fact,shared the 1987 Nobel Prize in Chemistry for contributions to the synthesis of crown ethers.Suppose you wanted to use a crown ether to selectively remove each individual cation from a solution of sodium,lithium,and potassium.For each cation,which crown ether might you add?

Accepted Answer

The answer of (a) Group I cations are common ions...

Question 8

Select a phrase to complete this sentence: "___________________ are induced dipole-induced dipole interactions common to nonpolar molecules such as hydrocarbons."

Accepted Answer

A)  Electromotive forces
B)  Hydrogen bonds
C)  Ionic attractions
D)  London dispersion forces
E)  Mechanical forces

Question 9

Explain the chemical difference between a detergent and a soap.Provide one example of each in your answer.

Accepted Answer

The answer of Explain the chemical difference between a detergent...

Question 10

The carbon atoms in the molecule below are labeled 1-8.Which CF1F1F1S1F1F1F10CF1F1F1S1F1F1F10F1F1F1S1F1F1F10C bond angle in the molecule would be approximately 180°?

Accepted Answer

A)  C1-C2-C3
B)  C2-C3-C4
C)  C4-C5-C6
D)  C5-C6-C7
E)  C6-C7-C8

Question 11

Rank the following molecules based on decreasing boiling point.

Accepted Answer

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

Question 12

Which of the following cycloalkanes contains a CF1F1F1S1F1F1F10CF1F1F1S1F1F1F10F1F1F1S1F1F1F10C bond angle of approximately 90°?

Accepted Answer

A)  A seven-membered cycloalkane
B)  A six-membered cycloalkane
C)  A five-membered cycloalkane
D)  A four-membered cycloalkane

Question 13

Rotate the molecule below 180°,in the same way you would flip a pancake or an egg during cooking.Which choice represents the product of the manipulation?

Accepted Answer

A)  Structure a
B)  Structure b
C)  Structure c
D)  Structure d
E)  Structure e

Question 14

Which of the following molecules contain(s)a nitrogen atom that has trigonal pyramidal molecular geometry?

Accepted Answer

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

Question 15

Which of the following statements is true about carbon tetrachloride,CCl4?

Accepted Answer

A)  It is polar protic with tetrahedral geometry.
B)  The carbon has trigonal planar geometry.
C)  None of the CCl bonds has a dipole.
D)  It is miscible in water with 109.5° bond angles.
E)  It is polar aprotic with tetrahedral geometry at C.

Question 16

Rank the following molecules based on increasing boiling point.

Accepted Answer

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

Question 17

A micelle is formed when soap dissolves in water.What intermolecular forces govern the formation of the micelle? Explain.

Accepted Answer

The answer of A micelle is formed when soap dissolves...

Question 18

Which of the following functional groups contains both a hydrogen-bond donor and a hydrogen-bond acceptor?

Accepted Answer

A)  Alkyl fluoride
B)  Epoxide
C)  Carboxylic acid
D)  Nitrile
E)  Ketone

Question 19

The carbon atoms in the molecule below are labeled 1-8.Which CF1F1F1S1F1F1F10CF1F1F1S1F1F1F10F1F1F1S1F1F1F10C bond angle in the molecule would be approximately 109.5°?

Accepted Answer

A)  C1-C2-C3
B)  C2-C3-C4
C)  C4-C5-C6
D)  C5-C6-C7
E)  C6-C7-C8

Question 20

When applying VSEPR theory to determine the geometry about a central atom,it is important to count the number of electron groups.Separately consider the two atoms highlighted with an arrow in the molecule shown below.How many electron groups must be considered for each of these central atoms?

Accepted Answer

A)  C1 has two groups; C2 has two groups.
B)  C1 has three groups; C2 has four groups.
C)  C1 has four groups; C2 has two groups.
D)  C1 has four groups; C2 has three groups.
E)  C1 has four groups; C2 has four groups.

Exam 4: Three-Dimensional Geometry,intermolecular Interactions,and Physical Properties

The carbon atoms in the molecule below are labeled 1-8.Which CCC bond angle in the molecule would be approximately 120°?

What are the approximate HCH bond angles expected for the carbanion whose structure is given in the ball-and-stick representation below?

Why do polar aprotic solvents solvate cations more strongly than anions? Using sodium chloride as the representative ionic compound,diagram the intermolecular interactions with tetrahydrofuran (THF).

Explain why polar protic solvents (like butanol)solvate anions (like chloride)better than polar aprotic solvents (like N,N-dimethylformamide,DMF)do.

A reverse micelle can form when a polar substance dissolves in a nonpolar substance.Create a conceptual diagram of a reverse micelle.What intermolecular forces are driving the formation of the reverse micelle?

Select a phrase to complete this sentence: "___________________ are induced dipole-induced dipole interactions common to nonpolar molecules such as hydrocarbons."

Explain the chemical difference between a detergent and a soap.Provide one example of each in your answer.

The carbon atoms in the molecule below are labeled 1-8.Which CCC bond angle in the molecule would be approximately 180°?

Rank the following molecules based on decreasing boiling point.

Which of the following cycloalkanes contains a CCC bond angle of approximately 90°?

Rotate the molecule below 180°,in the same way you would flip a pancake or an egg during cooking.Which choice represents the product of the manipulation?

Which of the following molecules contain(s) a nitrogen atom that has trigonal pyramidal molecular geometry?

Which of the following statements is true about carbon tetrachloride,CCl₄?

Rank the following molecules based on increasing boiling point.

A micelle is formed when soap dissolves in water.What intermolecular forces govern the formation of the micelle? Explain.

Which of the following functional groups contains both a hydrogen-bond donor and a hydrogen-bond acceptor?

The carbon atoms in the molecule below are labeled 1-8.Which CCC bond angle in the molecule would be approximately 109.5°?

When applying VSEPR theory to determine the geometry about a central atom,it is important to count the number of electron groups.Separately consider the two atoms highlighted with an arrow in the molecule shown below.How many electron groups must be considered for each of these central atoms?