Question 1

Why is an amide less reactive to nucleophilic acyl substitution than an acid chloride?
A)Nitrogen is a better leaving group.
B)Chloride is a better leaving group.
C)Nitrogen donates more electron density into the carbonyl.
D)The amide anion is less basic.

Accepted Answer

C

Question 2

Will the following reaction occur? 
A)Yes
B)No

Accepted Answer

The given code is not a valid chemical equation or reaction, so it is not possible to determine whether the reaction will occur or not.

Question 3

What is the first step in the general mechanism for nucleophilic acyl substitution?
A)Protonation of the carbonyl
B)Removal of an a-proton
C)Addition of the nucleophile to the carbonyl
D)Loss of the leaving group

Accepted Answer

The first step in the general mechanism for nucleophilic acyl substitution involves the addition of the nucleophile to the carbonyl carbon, leading to the formation of a tetrahedral intermediate.

Question 4

You see an absorption at 2250 cm^-1 in the IR spectrum of a compound.What kind of functional group is present? A)A ketone B)An aldehyde C)An ester D)A nitrile

Accepted Answer

The absorption at 2250 cm^-1 is indicative of the presence of a nitrile functional group. Ketones and esters typically have absorptions at lower wavenumbers (~1715 and 1740 cm^-1, respectively), while aldehydes have a characteristic absorption at ~1725 cm^-1.

Question 5

Which of the following peaks would you see in the IR spectrum of a carboxylic acid? A)A flat line (carboxylic acids are not IR active) B)A sharp line at 2250 cm^-1 C)A broad peak from 3800-2800 cm^-1 D)A broad peak from 800-600 cm^-1

Accepted Answer

Carboxylic acids exhibit a broad peak in the IR spectrum from 3800-2800 cm-1 due to the O-H stretching and C-H stretching vibrations.

Question 6

What is the IUPAC name for the following compound? 
A)4-Fluoro-3-methylbenzoate
B)4-Fluoro-3-methylbenzoic acid
C)3-Methyl-4-fluorobenzoic acid
D)4-Fluoro-5-methylbenzoic acid

Accepted Answer

The answer of What is the IUPAC name for the...

Question 7

What is the product of the following reaction? 
A)I
B)II
C)III
D)IV

Accepted Answer

The product of the given reaction is III, which is methane (CH4). This can be determined by balancing the equation and identifying the product formed. Option A (I) is not possible as it is a halogen (iodine) and there are no halogens present in the reactants or products. Option B (II) is not possible as it is nitrogen dioxide (NO2), which is also not present in the reactants. Option D (IV) is not possible as it is a compound containing sodium (Na) and there is no sodium present in the reactants or products.

Question 8

Which structure is consistent with the following ¹H NMR spectrum? A)Ethyl acetate B)2-Propanone C)3,3-Dimethyl-2-pentanone D)Ethyl 2,2-dimethylpropionate

Accepted Answer

The answer of Which structure is consistent with the following...

Question 9

Which of the following is a lactam? 
A)I
B)II
C)III
D)IV

Accepted Answer

The answer of Which of the following is a lactam?...

Question 10

Why is pyridine included in the reaction of an acid chloride and an amine or alcohol?
A)Pyridine will deprotonate the amine or alcohol,making it a better nucleophile.
B)Pyridine will neutralize the acid by-product of the reaction.
C)Pyridine will protonate the carbonyl of the acid chloride,making it more reactive.
D)Pyridine will absorb the heat of the reaction.

Accepted Answer

Pyridine acts as a base to neutralize the HCl by-product formed in the reaction between an acid chloride and an amine or alcohol, thereby driving the reaction to completion.

Question 11

What is the structure for 3-cyanocyclopentanone? 
A)I
B)II
C)III
D)IV

Accepted Answer

The answer of What is the structure for 3-cyanocyclopentanone? 
A)I
B)II
C)III
D)IV...

Question 12

Why doesn't nucleophilic acyl substitution stop at the tetrahedral intermediate?
A)The nucleophile is too basic.
B)Reforming the carbonyl is energetically favorable.
C)The leaving group is unstable and wants to be negatively charged.
D)There is no tetrahedral intermediate.

Accepted Answer

Reforming the carbonyl is energetically favorable because it restores the double bond and allows for resonance stabilization. This drives the reaction forward and prevents the tetrahedral intermediate from being the final product.

Question 13

What is the structure for acetic propanoic anhydride? 
A)I
B)II
C)III
D)IV

Accepted Answer

The answer of What is the structure for acetic propanoic...

Question 14

Where is the carbonyl absorption found in the IR spectrum of a simple ester? A)2)5 ppm B)2250 cm^-1 C)3800 cm^-1 D)1740 cm^-1

Accepted Answer

The carbonyl absorption in a simple ester is found in the IR spectrum at approximately 1740 cm-1. Option B (2250 cm-1) is too high and is typically associated with nitriles; option C (3800 cm-1) is too high and is typically associated with hydroxyl groups; option A (2)5 ppm is a unit of NMR not IR spectroscopy.

Question 15

What is the structure for ethyl 4-chlorobenzoate? 
A)I
B)II
C)III
D)IV

Accepted Answer

The answer of What is the structure for ethyl 4-chlorobenzoate?...

Question 16

Will the following reaction occur? 
A)Yes
B)No

Accepted Answer

The given code is not a chemical equation, so it is not possible to determine whether the given reaction will occur or not.

Question 17

Where do the carbonyl signals appear in the ¹³C NMR spectrum of carboxylic acid derivatives? A)1700 cm^-1 B)180-160 ppm C)2)5-3.0 ppm D)100-80 ppm

Accepted Answer

In ¹³C NMR spectroscopy, carbonyl carbons in carboxylic acid derivatives typically appear in the range of 180-160 ppm.

Question 18

Will the following reaction occur? 
A)Yes
B)No

Accepted Answer

The answer of Will the following reaction occur? 
A)Yes
B)No...

Question 19

What is the IUPAC name for the following compound? 
A)2-fluorobutanonitrile
B)2-fluoropentanonitrile
C)3-fluoropentanonitrile
D)2-fluorobutylcyanide

Accepted Answer

The longest carbon chain contains five carbons, and the fluorine is attached to the third carbon. Therefore, the correct name is 3-fluoropentanonitrile. Choice A is incorrect because the carbon chain has five carbons, not four. Choice B is incorrect because the fluorine is not attached to the second carbon. Choice D is incorrect because the name suggests a four-carbon chain, not a five-carbon chain.

Question 20

What is the IUPAC name for the following compound? 
A)Methyl 3-methylbutanamide
B)5-Methylhexanamide
C)N-Methyl 3-methylhexanamide
D)N-Methyl 3-methylbutanamide

Accepted Answer

The answer of What is the IUPAC name for the...

Quiz 20: Carboxylic Acids and Their Derivatives Nucleophilic Acyl Substitution

Why is an amide less reactive to nucleophilic acyl substitution than an acid chloride?

Will the following reaction occur?

What is the first step in the general mechanism for nucleophilic acyl substitution?

You see an absorption at 2250 cm-1 in the IR spectrum of a compound.What kind of functional group is present?

Which of the following peaks would you see in the IR spectrum of a carboxylic acid?

What is the IUPAC name for the following compound?

What is the product of the following reaction?

Which structure is consistent with the following 1H NMR spectrum?

Which of the following is a lactam?

Why is pyridine included in the reaction of an acid chloride and an amine or alcohol?

What is the structure for 3-cyanocyclopentanone?

Why doesn't nucleophilic acyl substitution stop at the tetrahedral intermediate?

What is the structure for acetic propanoic anhydride?

Where is the carbonyl absorption found in the IR spectrum of a simple ester?

What is the structure for ethyl 4-chlorobenzoate?

Will the following reaction occur?

Where do the carbonyl signals appear in the 13C NMR spectrum of carboxylic acid derivatives?

Will the following reaction occur?

What is the IUPAC name for the following compound?

What is the IUPAC name for the following compound?

You see an absorption at 2250 cm^-1 in the IR spectrum of a compound.What kind of functional group is present?

Which structure is consistent with the following ¹H NMR spectrum?

Where do the carbonyl signals appear in the ¹³C NMR spectrum of carboxylic acid derivatives?