Question 1

Are any of the four 1,2-difluorocyclopropane isomers drawn below polar? Indicate the direction of the net molecular dipole,if one is present.

Accepted Answer

The answer of Are any of the four 1,2-difluorocyclopropane isomers...

Question 2

How does the presence of the lone pair affect the geometry of the central atom in the following molecule? 
I The lone pair is attracted to the nuclei of the three substituents,creating larger bond angles.
II The lone pair repels the three sets of covalently bonded electrons.
III The lone pair has no bearing whatsoever on the VSEPR geometry at the central atom.
IVThe bond angles are smaller than a traditional tetrahedral bond angle due to lone pair repulsion.

Accepted Answer

The lone pair in the molecule will repel the three sets of covalently bonded electrons, leading to smaller bond angles than a traditional tetrahedral bond angle. This is known as the "lone pair effect". Therefore, option II is correct. Additionally, this effect will lead to larger bond angles between the substituents, as the lone pair is attracted to the nuclei of the substituents, which is described in option I. Therefore, E is the best choice.

Question 3

Sodium chloride,an ionic compound,is highly water soluble but minimally soluble in the polar aprotic solvent dimethyl sulfoxide (DMSO).Why?

Accepted Answer

The answer of Sodium chloride,an ionic compound,is highly water soluble...

Question 4

What is the strongest intermolecular attractive force possible between an alkyl chloride and an alkane?

Accepted Answer

The strongest intermolecular attractive force possible between an alkyl chloride and an alkane would be a dipole-induced dipole interaction because the alkyl chloride molecule has a permanent dipole due to the electronegativity difference between chlorine and carbon. This dipole can induce a dipole in the nonpolar alkane molecule, leading to an attractive force between the two molecules. Hydrogen bonds and ion-dipole and ion-ion interactions require highly polar species or charged molecules, which are not present in this case. Induced dipole-induced dipole interactions are weaker than dipole-induced dipole interactions.

Question 5

Identify the weakest intermolecular force.

Accepted Answer

Induced dipole-induced dipole forces, also known as London dispersion forces, are the weakest intermolecular forces as they arise from temporary fluctuations in electron distribution in atoms or molecules.

Question 6

Rank the following molecules based on decreasing boiling point.

Accepted Answer

The answer of Rank the following molecules based on decreasing...

Question 7

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 8

How many hydrogen-bond donors and acceptors are present in the following molecule?

Accepted Answer

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Question 9

Dimethyl sulfoxide (DMSO)is a polar aprotic solvent that is frequently used for organic reactions.Rank the following sodium halide salts for decreasing solubility in DMSO.

Accepted Answer

The answer of Dimethyl sulfoxide (DMSO)is a polar aprotic solvent...

Question 10

When mixed,which of the following pairs of compounds will exhibit both ion-dipole and ion-ion intermolecular attractive forces?

Accepted Answer

Ionic compounds exhibit ion-dipole interactions with polar covalent molecules and ion-ion interactions with other ions. Compound V is an ionic compound (NaCl) mixed with a polar covalent compound (water), resulting in both ion-dipole and ion-ion interactions. None of the other compounds have both types of interactions.

Question 11

Which functional group will engage in dipole-dipole interactions,but will not serve as a hydrogen-bond acceptor?

Accepted Answer

Alkyl bromides have a polar C-Br bond that can engage in dipole-dipole interactions, but they do not have lone pairs on electronegative atoms like N or O to act as hydrogen-bond acceptors.

Question 12

Consider the structure of sodium benzoate,NaOC(O)Ph,the sodium salt of benzoic acid.In which of the following solvents would you predict sodium benzoate to be soluble? IWater,H₂O IIPentane,CH₃(CH₂)₃CH₃ IIIDiethyl ether,(CH₃CH₂)₂O IVMethanol,CH₃OH VAcetone,CH₃C(O)CH₃

Accepted Answer

Sodium benzoate is a polar molecule due to the presence of a carboxylate group (-COO-) and is therefore expected to dissolve in polar solvents. Among the given options, water (I) and methanol (IV) are polar solvents and hence, sodium benzoate is expected to be soluble in both of them. Diethyl ether (III) is also a polar solvent and has a dipole moment of 1.15 D. Acetone (V) is a polar aprotic solvent and has a dipole moment of 2.88 D. However, pentane (II) is a nonpolar solvent and hence, sodium benzoate is not expected to be soluble in it. Therefore, the best choice(s) are options I and IV, and the correct answer is C.

Question 13

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

Accepted Answer

Carboxylic acid contains both a hydrogen-bond donor (the -OH group) and a hydrogen-bond acceptor (the carbonyl oxygen).

Question 14

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

Accepted Answer

London dispersion forces, also known as van der Waals forces, are the weakest type of intermolecular force and occur between all molecules, even nonpolar ones. These forces arise from the temporary dipoles that form as electrons move around within a molecule, causing a temporary partial charge imbalance that can induce a dipole in neighboring molecules.

Question 15

Add substituents using dash-wedge notation to achieve the structure specified.
(a) An alkene that has a fluorine atom pointing back on the leftmost carbon and a methyl group coming out on the rightmost carbon.Assume that hydrogen fills the valence of carbon.
(b) A tetrahedral carbon with two chlorine atoms pointing down on the plane of the paper,a bromine atom pointing up,and a hydrogen atom pointing back.

Accepted Answer

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Question 16

What is the strongest intermolecular attractive force between an alcohol and a ketone?

Accepted Answer

The strongest intermolecular attractive force between an alcohol and a ketone is hydrogen bonding. Alcohol and ketone molecules both have dipole moments due to the difference in electronegativity between oxygen and carbon. However, the presence of the -OH group in alcohols and the C=O group in ketones allows for hydrogen bonding between the molecules. The -OH group in alcohol can form a hydrogen bond with the C=O group in ketone, leading to stronger intermolecular attractive forces compared to other options mentioned.

Question 17

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

Accepted Answer

For the carbon atom highlighted with the arrow, there are three bonded electron groups (one with the hydrogen atom and two with the adjacent carbon atoms). 
For the oxygen atom highlighted with the arrow, there are two bonded electron groups (both with the adjacent carbon atoms).

Question 18

Rank the following molecules based on increasing boiling point.

Accepted Answer

Boiling point depends on intermolecular forces, with stronger forces resulting in higher boiling points.

Iodine (I₂) is a nonpolar molecule that experiences only weak London dispersion forces, so it has the lowest boiling point. Thus, I₂ must be the lowest boiling substance and should be ranked last.

Carbon tetrachloride (CCl₄) is a larger and more polar molecule than I₂, so it experiences stronger London dispersion forces. Thus, it should have a higher boiling point than I₂. So, II should be ranked higher than I.

Acetone (CH₃COCH₃) is a polar molecule that can form dipole-dipole interactions in addition to London dispersion forces, making its intermolecular forces stronger than CCl₄. Thus, it should have a higher boiling point than CCl₄. So, III should be ranked higher than II.

Butanal (CH₃CH₂CH₂CHO) is also a polar molecule but contains an additional -CHO group, enabling it to participate in hydrogen bonding. So, IV should have the highest boiling point, and it should be ranked higher than III.

Question 19

Which of the following intermolecular forces is responsible for the boiling-point trends in alkanes?

Accepted Answer

The boiling-point trends in alkanes can be explained by the strength of the intermolecular forces between the molecules. Alkanes only exhibit London dispersion forces (induced dipole-induced dipole interactions), as they do not contain polar bonds or hydrogen atoms bonded to electronegative atoms. The strength of these forces increases as the size of the molecule increases, due to the greater number of electrons which can form temporary dipoles. As a result, the boiling point increases as the size of the molecule increases. Therefore, option E - induced dipole-induced dipole - is the correct answer.

Question 20

Identify the strongest intermolecular force.

Accepted Answer

Ion-ion interactions are the strongest intermolecular forces because they involve the attraction between two oppositely charged ions.

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

Are any of the four 1,2-difluorocyclopropane isomers drawn below polar? Indicate the direction of the net molecular dipole,if one is present.

Sodium chloride,an ionic compound,is highly water soluble but minimally soluble in the polar aprotic solvent dimethyl sulfoxide (DMSO).Why?

What is the strongest intermolecular attractive force possible between an alkyl chloride and an alkane?

Identify the weakest intermolecular force.

Rank the following molecules based on decreasing boiling point.

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?

How many hydrogen-bond donors and acceptors are present in the following molecule?

Dimethyl sulfoxide (DMSO) is a polar aprotic solvent that is frequently used for organic reactions.Rank the following sodium halide salts for decreasing solubility in DMSO.

When mixed,which of the following pairs of compounds will exhibit both ion-dipole and ion-ion intermolecular attractive forces?

Which functional group will engage in dipole-dipole interactions,but will not serve as a hydrogen-bond acceptor?

Consider the structure of sodium benzoate,NaOC(O) Ph,the sodium salt of benzoic acid.In which of the following solvents would you predict sodium benzoate to be soluble? IWater,H₂O IIPentane,CH₃(CH₂) ₃CH₃ IIIDiethyl ether,(CH₃CH₂) ₂O IVMethanol,CH₃OH VAcetone,CH₃C(O) CH₃

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

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

What is the strongest intermolecular attractive force between an alcohol and a ketone?

Rank the following molecules based on increasing boiling point.

Which of the following intermolecular forces is responsible for the boiling-point trends in alkanes?

Identify the strongest intermolecular force.

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

Are any of the four 1,2-difluorocyclopropane isomers drawn below polar? Indicate the direction of the net molecular dipole,if one is present.

Sodium chloride,an ionic compound,is highly water soluble but minimally soluble in the polar aprotic solvent dimethyl sulfoxide (DMSO).Why?

What is the strongest intermolecular attractive force possible between an alkyl chloride and an alkane?

Identify the weakest intermolecular force.

Rank the following molecules based on decreasing boiling point.

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?

How many hydrogen-bond donors and acceptors are present in the following molecule?

Dimethyl sulfoxide (DMSO) is a polar aprotic solvent that is frequently used for organic reactions.Rank the following sodium halide salts for decreasing solubility in DMSO.

When mixed,which of the following pairs of compounds will exhibit both ion-dipole and ion-ion intermolecular attractive forces?

Which functional group will engage in dipole-dipole interactions,but will not serve as a hydrogen-bond acceptor?

Consider the structure of sodium benzoate,NaOC(O) Ph,the sodium salt of benzoic acid.In which of the following solvents would you predict sodium benzoate to be soluble? IWater,H2O IIPentane,CH3(CH2) 3CH3 IIIDiethyl ether,(CH3CH2) 2O IVMethanol,CH3OH VAcetone,CH3C(O) CH3

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

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

What is the strongest intermolecular attractive force between an alcohol and a ketone?

Rank the following molecules based on increasing boiling point.

Which of the following intermolecular forces is responsible for the boiling-point trends in alkanes?

Identify the strongest intermolecular force.

Consider the structure of sodium benzoate,NaOC(O) Ph,the sodium salt of benzoic acid.In which of the following solvents would you predict sodium benzoate to be soluble? IWater,H₂O IIPentane,CH₃(CH₂) ₃CH₃ IIIDiethyl ether,(CH₃CH₂) ₂O IVMethanol,CH₃OH VAcetone,CH₃C(O) CH₃