Amines MCQ Class 12 Chapter 13 Question 1.

CH₃CONH₂ on reaction with NaOH and Br₂ in alcoholic medium gives:

(A) CH₃CH₂NH₂
(B) CH₃CH₂Br
(C) CH₃NH₂
(D) CH₃COONa
Answer:
(C) CH₃NH₂

Explanation:

Amines Class 12 MCQ Chapter 13 Question 2.

Propanamide on reaction with bromine in aqueous NaOH gives:

(A) Propanamine
(B) Ethanamine
(C) N-Methyl ethanamine
(D) Propanenitrile

OR

IUPAC name of product formed by reaction of methyl amine with two moles of ethyl chloride

(A) N,N-Dimethylethanamine
(B) N,N-Diethylmethanamine
(C) N-Methyl ethanamine
(D) N-Ethyl – N-methylethanamine
Answer:
(B) N,N-Diethylmethanamine

Explanation:

properties, uses, identification of primary, secondary and tertiary amines.

OR

Answer:
(D) N-Ethyl – N-methylethanamine

Explanation:
By reaction of methyl amine with two moles of ethyl chloride, N-Ethyl – N-methylethanamine is formed.

MCQ On Amines Class 12 Chapter 13 Question 3.

Which of the following reagents would not be a good choice for reducing an aryl nitro compound to an amine?

(A) H₂(excess)/Pt
(B) LiAIH₄ in ether
(C) Fe and HCI
(D)SnandHCl
Answer:
(B) LiAIH₄ in ether

Explanation:

MCQ On Amines Class 12 Chapter 13 Question 4.

The correct increasing order of basic strength for the following compounds is ………..

(A) II < III< I
(B) III < I < II
(C) III < II< I
(Ð) III < I < I
Answer:
(Ð) III < I < I

Explanation:

Electron withdrawing group decreases the basic strength while electron releasing groups increases the basic strength of aniline.

Amines Class 12 MCQ Pdf Chapter 13 Question 5.

The best reagent for converting2-Phenylpr0Pam1de into 2-phenyipropananhirie as …………

(A) excess H₂
(B) Br₂ in aqueous NaOH
(C) Iodine in the presence of red phosphorus
(D) LIAIH₄ in ether
Answer:
(D) LIAIH₄ in ether

Explanation:

MCQ Of Amines Class 12 Chapter 13 Question 6.

Hinsberg’s reagent which is used to test amines is

(A) Benzene suiphonamide
(B) Benzene diazonium chloride
(C) Benzene sulphonyl chloride
(D) Acetanilide
Answer:
(C) Benzene sulphonyl chloride

Explanation:
Hinsberg’s reagent which is used to test amines is benzene suiphonyl chloride.

MCQs On Amines Class 12 Chapter 13 Question 7.

The best method for preparing primary amines from alkyl halides without changing the number of carbon atoms in the chain is:

(A) Hoffmann Bromamide reaction
(B) Gabriel phthalimide synthesis
(C) Sandmeyer reaction
(D) Reaction with NH₃ CRI
Answer:
(B) Gabriel phthalimide synthesis

explanation:
Gabriel phthalimide synthesis is used to get primary amines from alkyl halides without changing the number of carbon atoms.

Amines MCQs Class 12 Chapter 13 Question 8.

Write IUPAC name of the following compound:

(A) N,N-Dimethylpropanamifle
(B) I ,l-Dimethylbutanamifle
(C) N-Methylpentan-1-amifle
(D) N,N.Dimethylbutafl-1-amine
Answer:
(D) N,N.Dimethylbutafl-1-amine

Explanation:

IUPAC name: N, N – Dimethyl butan-1-aniine

Amines MCQ Pdf Class 12 Chapter 13 Question 9.

Thecorrect IUPAC name for CH₂=CHCH₂NHCH₃ is:

(A) Aflylmethylamine
(B) 2-ariiino-4-pentene .
(C) 4-aminopent-1-ene
(D) N-methylprop-2-en-1-amifle
Answer:
(D) N-methylprop-2-en-1-amifle

Explanation:
CH₂ = C₂HC₁H₂NIICH₃
IUPAC naine: N-methylprop-2-en-1-amifle

Class 12 Chemistry Chapter 13 MCQ Question 10.

Which of the following is a 3° amine?

(A) 1-methylcydohexylamine
(B) Triethylaniine
(C) tert-butylamirie
(D) N-methylaniline
Answer:
(B) Triethylaniine

Explanation:
Triethylamine [(CHN] is a 30 or tertiary amine as nitrogen atom contains three ethyl groups

Amines MCQ Questions Class 12 Chapter 13 Question 11.

Methylamine reacts with HNO2 to form

(A) CH₃-O-N=O
(B) CH₃-O-CH₃
(C) CH₃OH
(D) CH₃CHO

OR

The gas evolved when methylamine reacts with nitrous acid is:

(A) NH₃
(B) N₂
(C) H₂
(D) C₂H₆
Answer:
(C) H₂

Explanation:
Methylamine reacts with HNO₂ to form CH₃OH

Answer:
(B) N₂

Explanation:
Nitrogen gas is evolved.

Class 12 Chemistry Amines MCQ Chapter 13 Question 12.

Arrange the following in increasing order of basic strength:

Aniline, p-nitroaniline and p-toludine.
(A) Aniline < p-Nitroaniline < p-Toluidine
(B) Aniline < p-Toluidine < p-Nitroaniline
(C) p-Toluidine < p-Nitroaniline < Aniline
(D) p-Nitroaniline < Aniline < p-Toluidine
Answer:
(D) p-Nitroaniline < Aniline < p-Toluidine

Explanation:

MCQ On Aromatic Amines Class 12 Chapter 13 Question 13.

Which of the following species are involved in the carbylamine test ?

(A) R-NC
(B) COCl₂
(C) NaNO₂ + HCl
(D) All of the above
Answer:
(A) R-NC

Explanation:
In the carbylamine test, a primary amine reacts with chloroform and KOH to form alkyl isocyanide (i.e. R-NC) having unpleasant smell.

Question 14.

Which of the following amines can be prepared by Gabriel synthesis ?

(A) Isobutyl amine
(B) Toluene
(C) N-methylbenzylamine
(D) Aniline
Answer:
(A) Isobutyl amine

Explanation:
Gabriel phthalamide synthesis cannot be used for preparation of aromatic amines, as aromatic halides do not undergo nucleophilic substitution by salt formed by phthalamide

Question 15.

Which of the following should be most volatile ?

(A) (ii)
(B) (iv)
(C) (i)
(D) (iii)
Answer:
(B) (iv)

Explanation:
Primary and secondary amines form hydrogen bonds and hence are less volatile than corresponding alkanes.

Assertion And Reason Based MCQs

Directions: In the following questions, A statement of Assertion (A) is followed by a statement of Reason (R). Mark the correct choice as.
(A) Both A and R are true and R is the correct explanation of A
(B) Both A and R are true but R is NOT the correct explanation of A
(C) A is true but R is false
(D) A is false and R is True

Question 1.

Assertion (A): Acylation of amines gives a monosubstituted product whereas alkylation of amines gives poly substituted product.
Reason (R): Acyl group sterically hinders the approach of further acyl groups.

Answer:
(C) A is true but R is false

Explanation:
In alleviation, an amine can react with alkyl halide to form next higher class of amine caused by the presence of electron pair on nitrogen which makes amine to behave as nucleophile and alkyl halide thus undergo nucleophilic substitution reaction. When primary and secondary amines react with acid chlorides, anhydrides and esters to give monosubstituted amides as products. Acylation is carried out in the presence of a base stronger than the amine like pyridine which causes the shift of the equilibrium to the right side.

Question 2.

Assertion (A): Acetanilide is less basic than aniline.
Reason (R): Acetylation of aniline results in decrease of electron density on nitrogen.

Answer:
(A) Both A and R are true and R is the correct explanation of A

Explanation:
Acetanilide is less basic than aniline as in amides the carbonyl group (C=0) is a stronger dipole than N-C dipole. Therefore, the ability of N-C group to act as H-bond acceptor (as a base) is restricted in the presence of a C=0 dipole.

Question 3.

Assertion (A): N, N-Diethylbenzene sulphonamide is insoluble in alkali.
Reason (R): Suiphonyl group attached to nitrogen atom is strong electron withdrawing group.

Answer:
(A) Both A and R are true and R is the correct explanation of A

Explanation:
N,N-Diethylbenzenesulphonamide is insoluble in alkali because it has no acidic hydrogen. Sulphonyl group attached to nitrogen atom is electron withdrawing group

Question 4.

Assertion (A): Aromatic 1° amines can be prepared by Gabriel Phthalimide synthesis.
Reason (R): Aryl halides do not undergo nucleophilic substitution with anion formed by phthalimide.

Answer:
(D) A is false and R is True

Explanation:
Aromatic 1° amines cannot be prepared by Gabriel Phthalimide synthesis because aryl halides do not undergo nucleophilic substitution with anion formed by phthalimide.

Case-Based MCQs

I. Read the passage given below and answer the following questions:

Greater is the stability of the substituted ammonium cation, stronger should be the corresponding amine as a base. Thus, the order of basicity of aliphatic amines should be: primary > secondary > tertiary, which is opposite to the inductive effect based order. Secondly, when the alkyl group is small, like -CH₃ group, there is no steric hindrance to H-bonding. In case the alkyl group is bigger than CH3 group, there will be steric hinderance to H-bonding. Therefore, the change of nature of the alkyl group, e.g., from -CH₃ to -C₂H₅ results in change of the order of basic strength.

In the following questions a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices.
(A) Assertion and reason both are correct statements and reason is correct explanation for assertion.
(B) Assertion and reason both are correct statements but reason is not correct explanation for assertion.
(C) Assertion is correct statement but reason is wrong statement.
(D) Assertion is wrong statement but reason is correct statement.

Question 1.

Assertion (A): (CH₃)₂NH > CH₃NH₂ > (CH₃)₃N > NH₃ is the order of basic strength in case of methyl substituted amines.
Reason (R): The inductive effect, solvation effect and steric hindrance of the alkyl group decides the basic strength of alkyl amines in the aqueous state.

Answer:
(A) Assertion and reason both are correct statements and reason is correct explanation for assertion.

Explanation:
(CH₃)₂NH > CH₃NH₂ > (CH₃)₃N > NH₃ is the order of basic strength in case of methyl substituted amines as the inductive effect, solvation effect and steric hinderance of the alkyl group decides the basic strength of alkyl amines in the aqueous state.

Question 2.

Assertion (A): (C₂H₅)₂NH > (C₂H₅)₃N > C₂H₅NH₂ > NH₃ is the order of basic strength in case of ethyl substituted amines.
Reason (R): The change of nature of the alkyl group, does not result in change of the order of basic strength.

Answer:
(C) Assertion is correct statement but reason is wrong statement.

Explanation:
(C₂H₅)₂NH > (C₂H₅)₃N > C₂H₅NH₂ > NH₃ is the order of basic strength in case of ethyl substituted amines. The change of nature of the alkyl group, results in change of the order of basic strength.

Question 3.

Assertion (A): Greater is the stability of the substituted ammonium cation, stronger is the corresponding amine as a base.
Reason (R): The order of basicity of aliphatic amines is: primary > secondary > tertiary.

Answer:
(C) Assertion is correct statement but reason is wrong statement.

Explanation:
Greater is the stability of the substituted ammonium cation, stronger is the corresponding amine as a base but the inductive effect, solvation effect and steric hinderance of the alkyl group decides the basic strength of alkyl amines in the aqueous state.

Question 4.

Assertion (A): Amines behave as a Lewis base.
Reason (R): Amines have an unshared pair of electrons on nitrogen atom.

Answer:
(A) Assertion and reason both are correct statements and reason is correct explanation for assertion.

Explanation:
Amines behave as a Lewis base as they have an unshared pair of eleolrons on nitrogen atom.

OR

Assertion (A): Solubility of amines in water decreases with increase in molar mass.
Reason (R): Intermolecular H bonds formed by the higher amines are weaker.

Answer:
(C) Assertion is correct statement but reason is wrong statement.

Explanation:
Lower aliphatic amines are soluble in water because thcv can form hydrogen bonds with water molecules. 1 lowever, solubility decreases with increase in molar mass of amines due to increase in size of the hydrophobic alkvl part.

II. Read the passage given below and answer the following questions: (1 x 4 = 4)
Benzene ring in aniline is highly activated. This is due to the sharing of lone pair of nitrogen with the ring which results in increase in the electron density on the ring and hence facilitates the electrophilic attack. The substitution mainly takes place at ortho and para positions because electron density is more at ortho and para positions. On reaction with aqueous bromine all the ortho and para positions get substituted resulting in the formation of 2,4,6-tribromoaniline. To get a monobromo compound, the amino group is acetylated before bromination. After bromination, the bromoacetanilide is acid hydrolysed to give the desired halogenated amine.

In the following questions, a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices :
(A) Assertion and reason both are correct statements and reason is correct explanation for assertion.
(B) Assertion and reason both are correct statements but reason is not correct explanation for assertion.
(C) Assertion is correct statement but reason is wrong statement.
(D) Assertion is wrong statement but reason is correct statement.

Question 1.

Assertion (A): Benzene ring is aniline is highly deactivated.
Reason (R): In aniline, the sharing of lone pair of nitrogen with the ring increases the electron density on the ring.

Answer:
(D) Assertion is wrong statement but reason is correct statement.

Explanation:
Benzene ring in aniline is highly activated.

Question 2.

Assertion (A): In aniline -NH₂ group facilitates the electrophilic attack.
Reason (R): It is due to decrease in electron density on the ring.

Answer:
(C) Assertion is correct statement but reason is wrong statement.

Explanation:
In aniline, -NHL group facilitates the electrophilic attack because the sharing of, lone pair of nitrogen with the ring increases the electron density on the ring.

Question 3.

Assertion (A): In aniline, the substitution mainly takes place at ortho and para positions.
Reason (R): The electron density is more at ortho and para positions.

Answer:
(C) Assertion is correct statement but reason is wrong statement.

Explanation:
In aniline, the electron density is more at ortho and para positions than meta position, so, the substitution mainly takes place at ortho and para positions. The above resonating structures of aniline show more electron density at the ortho and para positions.

Question 4.

Assertion (A): The amino group of aniline is acetylated before bromination.
Reason (R): It is due to the strong deactivating effect of -NH₂ group.

Answer:
(C) Assertion is correct statement but reason is wrong statement.

Explanation:
-NHL group of aniline is acetylated before bromination due to the strong activating effect of -NIL group.

III. Read the passage given below and answer the following questions:

The main problem encountered during electrophilic substitution reactions of aromatic amines is that of their very high reactivity. Substitution tends to occur at ortho and para- positions. If we have to prepare monosubstituted aniline derivative, how can the activating affect of -NH2 group be controlled? This can be done by protecting the -NH₂ group By acetylation with acetic anhydride, then carrying out the desired substitution followed by hydrolysis of the substituted amide to the substituted amine.

Question 1.

Give the major product of the following reaction:

Answer:
(C)

Explanation:

Question 2.

What is the major product A of the following reaction:

Answer:
(B)

Explanation:

Question 3.

Why is the activating effect of -NHCOCH3 group in the above reaction less than the activating effect of amino group?

(A) Due to mesomeric effect of benzene ring.
(B) Due to inductive effect of alkyl group.
(C) Due to resonance effect of acetanilide.
(D) All of the above.
Answer:
(C) Due to resonance effect of acetanilide.

Explanation:
The lone pair of electrons on nitrogen of acetanilide interacts with oxygen atom due to resonance as shown below:

Hence, the lone pair of electrons on nitrogen is less available for donation to benzene ring by resonance. Therefore, activating effect of – NHCOCH3 group is less than that of amino group.

Question 4.

Aniline is a resonance hybrid of

(A) 3 structures
(B) 6 structures
(C) 2 structures
(D) 5 structures
Answer:
Option (D) is correct.

Explanation:
Aniline is a resonance hybrid of 5 structures.

MCQ Questions for Class 12 Chemistry with Answers