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Which best describes the reactivity of acyl halides? All of the above
Main idea: Acyl halides are the most reactive carboxylic acid
derivative because the halide is a good leaving group.
A: Correct - but not the best answer. Carboxylic acids are less reactive
than acyl halides due to the poor leaving group (the hydroxyl group).
B: Correct - but not the best answer. Esters are less reactive than acyl
halides because the alkoxy group is a poor leaving group.
C: Correct - but not the best answer. Amides are the least reactive
because the amino group is a very poor leaving group.
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Which two reactants form propanoyl chloride? Propanoic acid and SOCl2
Main idea: SOCl2 is a synthesis reagent used to convert alcohols and
carboxylic acids to acyl chlorides due to its strong
electrophilicity.
A: Incorrect - This reagent oxidizes alcohols
C: Incorrect - This reagent converts carboxylic acids to acyl bromides.
D: Incorrect - Two carboxylic acids would form an acid anhydride.
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What is the primary reason why propanoyl chloride is more reactive than
propanoic acid? the leaving group
Main idea: Halogens are good leaving groups because they act as weak
bases and can stabilize the negative charge after leaving, making
halides highly reactive.
B - Incorrect - The nucleophile is not the reason for high reactivity,
but it is a good electron donor that forms a bond with the
electrophile.
C - Incorrect - The carbonyl carbon is not the reason for high
reactivity, but it is the electrophilic center that reacts with the
nucleophile.
D - Incorrect - The alkyl group is not the reason for high reactivity,
but it can influence the reactivity through inductive effects.
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Which two molecules are most likely to react to form an acid anhydride? A carboxylic acid and an acid chloride or two carboxylic acids
Main idea: Acid anhydrides can be formed from the reaction of two
carboxylic acids or a carboxylic acid and an acyl chloride.
A - Incorrect - Two alcohols would form an ether.
B - Correct but not the best answer - Two carboxylic acids can form an
acid anhydride, but it is less efficient than using an acyl chloride.
D - Incorrect - An amine and a carboxylic acid would form an amide.
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Two molecules, both with three carbons, react to form an acid anhydride.
What is the name of the product? Propanoic anhydride
Main idea: The correct nomenclature for acid anhydrides is to use the
name of the carboxylic acid, remove "acid," and add
"anhydride."
A - Incorrect - The word "acid" is not included in the name of acid
anhydrides.
C - Incorrect - The prefix "di-" is not used in the nomenclature of acid
anhydrides.
D - Incorrect - The term "anhydride" is used without the "acid"
prefix.
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Acetic anhydride would be:
More reactive than esters but less reactive than acid chlorides
Main idea: Acid anhydrides are more reactive than esters but less
reactive than acyl halides because their leaving group is a
carboxylate, which is a weaker base than an alkoxide but a stronger
base than a chloride.
A - Incorrect - This would imply that acetyl chloride is less reactive
than acetic anhydride, which is not true.
B - Incorrect - Acetic anhydride is more reactive than ethyl acetate
because its leaving group (carboxylate) is a weaker base than the
leaving group (alkoxide) in ethyl acetate.
D - Incorrect - Acetic anhydride is less reactive than acetyl chloride
because its leaving group (carboxylate) is a stronger base than the
leaving group (chloride) in acetyl chloride.
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Which acid derivative can form hydrogen bonds with other molecules? amides
Main idea: Amides can form hydrogen bonds because they contain an N-H
bond, which allows them to act as both hydrogen bond donors and
acceptors.
A - Incorrect - Acyl halides cannot form hydrogen bonds because they do
not have N-H or O-H bonds.
B - Incorrect - Acid anhydrides cannot form hydrogen bonds because they
do not have N-H or O-H bonds.
C - Incorrect - Esters cannot form hydrogen bonds because they do not
have N-H or O-H bonds.
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Which of the following is less water-soluble than butyl acetate? pentyl acetate
Main idea: Increasing the length of the carbon chain decreases the
solubility of esters as it makes them less polar.
B - Incorrect - Propyl acetate has a shorter carbon chain than butyl
acetate, making it more polar and thus more water-soluble.
C - Incorrect - Propyl propanoate has a similar carbon chain length to
butyl acetate, making their polarities and water solubilities
comparable.
D - Incorrect - Ethyl acetate has a shorter carbon chain than butyl
acetate, making it more polar and thus more water-soluble.
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Which two reactants are most likely to form propyl butanoate? propanol and butanoic acid
Main idea: The reaction between an alcohol and a carboxylic acid
forms an ester.
B - Incorrect - Butanol and propanoic acid would form butyl propanoate,
not propyl butanoate.
C - Incorrect - Propanol and acetic acid would form propyl acetate, not
propyl butanoate.
D - Incorrect - Butanol and acetic acid would form butyl acetate, not
propyl butanoate.
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Which best describes the boiling points of amides? higher than esters
Main idea: Amides have higher boiling points than all other
carboxylic acid derivatives due to their ability to form stronger
hydrogen bonds.
A - Incorrect - Amides have higher boiling points than esters due to
stronger hydrogen bonding.
B - Incorrect - Amides have higher boiling points than alkanes due to
stronger intermolecular forces.
D - Incorrect - Amides have higher boiling points than acyl halides due
to their ability to form stronger hydrogen bonds.
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N-methyl-butanamide is most likely formed from which two reactants? butanamide and methylamine
Main idea: Amides are formed from the reaction of carboxylic acids
and amines.
A - Incorrect - Butanamide and methylamine would not react to form
N-methyl-butanamide. Amides are much less reactive than carboxylic
acids.
C - Incorrect - Butanamine and methanol would not form
N-methyl-butanamide.
D - Incorrect - Butanamide and methanol would not react to form
N-methyl-butanamide.
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Which increases the reactivity of acid derivatives? induction
Main idea: Induction increases the electrophilicity of the carbonyl
carbon due to the electronegativity of the carbonyl oxygen, making it
more susceptible to nucleophilic attack, while resonance stabilizes
the molecule and decreases its reactivity.
B - Incorrect - Resonance decreases the reactivity of acid derivatives
by delocalizing the positive charge on the carbonyl carbon.
C - Incorrect - While induction increases reactivity, resonance
decreases it, so they do not both increase reactivity.
D - Incorrect - Induction does increase reactivity, so this option is
incorrect.
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Which reaction would ethyl acetate undergo when treated with H2O
/ HCl? hydrolysis to form ethanol and acetic acid
Main idea: Esters undergo hydrolysis in the presence of water and an
acid catalyst to form a carboxylic acid and an alcohol.
The water acts as a nucleophile, attacking the electrophilic carbonyl,
while the acid catalyst protonates the carbonyl oxygen, increasing its
electrophilicity. This leads to the breakdown of the ester into its
constituent alcohol and carboxylic acid.
A - Incorrect - Nucleophilic substitution typically involves the
replacement of the ester group with another nucleophile such as a
halide, which would not result from the reagents above.
B - Incorrect - Electrophilic addition is not a typical reaction for
esters.
D - Incorrect - Elimination reactions are not typical for esters. While
elimination reactions utilize an H2O reagent, they typically
involve the removal of a strong leaving group such as a halogen, not the
formation of a carboxylic acid.
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Which of the following reagents can be used to convert an amide to a
carboxylic acid? aqueous acid or base
Main idea: Amides can be hydrolyzed to carboxylic acids in the
presence of aqueous acid or base.
B - Incorrect - LiAlH4 is a strong reducing agent that converts amides
to amines, not carboxylic acids.
C - Incorrect - NaBH4 is a milder reducing agent that typically does not
reduce amides.
D - Incorrect - Only aqueous acid or base can convert an amide to a
carboxylic acid; LiAlH4 cannot.
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Which reagent can be used to convert an amide to an amine? LiAlH4
Main idea: LiAlH4 is a strong reducing agent that can convert amides
to amines by reducing the carbonyl group to a methylene group.
A - Incorrect - Aqueous acid or base would hydrolyze the amide to a
carboxylic acid and an amine, not reduce it to an amine.
C - Incorrect - NaBH4 is a milder reducing agent that typically does not
reduce amides.
D - Incorrect - Only LiAlH4 can convert an amide to an amine; aqueous
acid or base cannot.
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Which alkyl group would be LEAST likely to lead to a reaction seen in acid
derivatives? a tert-butyl group
Main idea: Tert-butyl groups are bulky and create steric hindrance,
making it difficult for nucleophiles to approach the electrophilic
carbonyl carbon in acid derivatives.
A - Incorrect - Methyl groups are small and do not create significant
steric hindrance, allowing nucleophiles to easily approach the carbonyl
carbon.
B - Incorrect - Primary alkyl groups are less bulky than tert-butyl
groups, allowing nucleophiles to approach the carbonyl carbon more
easily.
C - Incorrect - Secondary alkyl groups are bulkier than primary groups
but still less bulky than tert-butyl groups, allowing some nucleophilic
access to the carbonyl carbon.
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Which example is best representative of transesterification? Methyl butanoate + propanol ⇌ propyl butanoate + methanol
Main idea: Transesterification is the process of converting one ester
into another ester by reacting it with an alcohol, typically in the
presence of an acid or base catalyst such as sulfuric acid.
B - Incorrect - The product "butyl butanoate" is incorrect; it should be
"propyl butanoate", because the alcohol oxygen replaces alkoxy in the
starting ester, it does not add to it.
C - Incorrect - The product "butyl butanoate" is incorrect because the
alcohol oxygen replaces alkoxy in the starting ester, it does not add to
it. Additionally, there is an extra methanol produced in this
hypothetical reaction.
D - Incorrect - The products would be an expected result if butyl
methanoate reacted with ethanol.
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The beta-lactam ring is classified as a: cyclic amide
The ring (highlighted in red) contains a nitrogen atom bonded to the
carbonyl carbon, characteristic of an amide functional
group.
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The beta-lactam ring is effective against bacteria because: The strain in the beta-lactam ring makes it susceptible to hydrolysis by
bacterial enzymes
Main idea: The beta-lactam ring is a four-membered cyclic amide that
is highly strained, making it more reactive and susceptible to
hydrolysis by bacterial enzymes such as beta-lactamases.
A - Incorrect - Polarity does not play a significant role in the
effectiveness against bacteria. Its effectiveness is primarily due to
its reactivity and susceptibility to enzymatic hydrolysis, not its
ability to cross cell membranes.
B - Incorrect - The beta-lactam ring does not form strong hydrogen bonds
with bacterial proteins; its effectiveness is due to its reactivity and
susceptibility to enzymatic hydrolysis.
C - Incorrect - The beta-lactam ring does not contain an acyl chloride
group; it is a cyclic amide. Its effectiveness is due to its strain and
susceptibility to enzymatic hydrolysis.
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Acid chlorides are polar, so why can't they be dissolved in water? They react violently with water
Main idea: Acid chlorides are highly reactive with water due to the
electrophilic nature of the carbonyl carbon, which is further
activated by the electron-withdrawing chlorine atom. This leads to
rapid hydrolysis, producing carboxylic acids and hydrochloric acid,
making them unsuitable for dissolution in water.
A - Incorrect - Acid chlorides are polar due to the presence of the
carbonyl group and the electronegative chlorine atom.
B - Incorrect - Molecular weight does not determine solubility; rather,
it is the chemical reactivity and interactions with the solvent.
D - Incorrect - While acid chlorides are polar, their reactivity with
water is the primary reason they cannot be dissolved in it.
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Which of the following cannot act as a good leaving group? NH2-
Main idea: A good leaving group is typically a weak base that can
stabilize the negative charge after leaving.
A - Incorrect - Cl- is a good leaving group because it is the conjugate
base of a strong acid (HCl) and can stabilize the negative charge
well.
C - Correct but not optimal - OR- (alkoxide) can be a good leaving group
in certain contexts, especially when the reaction conditions favor its
departure, such as in acidic conditions where it can be protonated to
form an alcohol.
D - Correct but not optimal - OH- is generally a poor leaving group in
neutral or basic conditions, but it can be a good leaving group in
acidic conditions where it can be protonated to form water, which is a
very good leaving group.
