Q 1 :

Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).

Assertion (A):  undergoes ${\mathrm{S}}_{\mathrm{N}}2$ reaction faster than .

Reason (R): Iodine is a better leaving group because of its large size.

In the light of the above statements, choose the correct answer from the options given below:         [2025]

• A is true but R is false.

   

• A is false but R is true.

   

• Both A and R are true and R is the correct explanation of A.

   

• Both A and R are true but R is not the correct explanation of A.

   

Q 2 :

How many products (including stereoisomers) are expected from monochlorination of the following compound?         [2025]

• 5

   

• 6

   

• 2

   

• 3

   

Q 3 :

The major product C in the below mentioned reaction is           [2024]

${\mathrm{CH}}_3{\mathrm{CH}}_2{\mathrm{CH}}_2\mathrm{Br} \underset{\Delta }{\overset{\text{alc. KOH}}{\to }}A \stackrel{\text{HBr}}{\to }B \underset{\Delta }{\overset{\text{aq. KOH}}{\to }}C$

• propan-1-ol

   

• propan-2-ol

   

• propane

   

• propyne

   

Q 4 :

The compound that will undergo ${\mathrm{S}}_{\mathrm{N}}1$ reaction with the fastest rate is          [2024]

Q 5 :

Major products A and B formed in the following reaction sequence are         [2024]

Q 6 :

Identify ‘X’ in the following reaction.                [2023]

Q 7 :

The correct order for the rate of $\mathrm{\alpha },\mathrm{\beta }$-dehydrohalogenation for the following compounds is _______.         [2023]

• (i) < (ii) < (iii)

   

• (ii) < (i) < (iii)

   

• (iii) < (ii) < (i)

   

• (ii) < (iii) < (i)

   

Q 8 :

Which amongst the following reactions of alkyl halides produces isonitrile as a major product?

A)  $\mathrm{R}-\mathrm{X}+\mathrm{HCN}⟶$ 
B)  $\mathrm{R}-\mathrm{X}+\mathrm{AgCN}⟶$ 
C)  $\mathrm{R}-\mathrm{X}+\mathrm{KCN}⟶$ 
D)  $\mathrm{R}-\mathrm{X}+\mathrm{NaCN}\underset{{\mathrm{C}}_2{\mathrm{H}}_5\mathrm{OH}}{\overset{{\mathrm{H}}_2\mathrm{O}}{\to }}$

Choose the most appropriate answer from the options given below:              [2023]

• (D) only

   

• (C) and (D) only

   

• (B) only

   

• (A) and (B) only

   

Q 9 :

The incorrect statement regarding chirality is             [2022]

• ${\mathrm{S}}_{\mathrm{N}}1$ reaction yields 1 : 1 mixture of both enantiomers

   

• the product obtained by ${\mathrm{S}}_{\mathrm{N}}2$ reaction of haloalkane having chirality at the reactive site shows inversion of configuration

   

• enantiomers are superimposable mirror images of each other

   

• a racemic mixture shows zero optical rotation

   

Q 10 :

The major product formed in dehydrohalogenation reaction of 2-bromopentane is pent-2-ene. This product formation is based on?         [2021]

• Huckel’s Rule

   

• Saytzeff’s Rule

   

• Hund’s Rule

   

• Hofmann Rule

   

Q 11 :

Elimination reaction of 2-bromopentane to form pent-2-ene is

(A)  $\mathrm{\beta }$-Elimination reaction
(B)  follows Zaytsev rule
(C)  dehydrohalogenation reaction
(D)  dehydration reaction                                                         [2020]

• (A), (B), (C)

   

• (A), (C), (D)

   

• (B), (C), (D)

   

• (A), (B), (D)

   

Q 12 :

The hydrolysis reaction that takes place at the slowest rate, among the following is         [2019]

Q 13 :

The compound A on treatment with Na gives B, and with ${\mathrm{PCl}}_5$ gives C. B and C react together to give diethyl ether. A, B and C are in the order       [2018]

• ${\mathrm{C}}_2{\mathrm{H}}_5\mathrm{OH},{\mathrm{C}}_2{\mathrm{H}}_6,{\mathrm{C}}_2{\mathrm{H}}_5\mathrm{Cl}$

   

• ${\mathrm{C}}_2{\mathrm{H}}_5\mathrm{OH},{\mathrm{C}}_2{\mathrm{H}}_5\mathrm{Cl},{\mathrm{C}}_2{\mathrm{H}}_5\mathrm{ONa}$

   

• ${\mathrm{C}}_2{\mathrm{H}}_5\mathrm{Cl},{\mathrm{C}}_2{\mathrm{H}}_6,{\mathrm{C}}_2{\mathrm{H}}_5\mathrm{OH}$

   

• ${\mathrm{C}}_2{\mathrm{H}}_5\mathrm{OH},{\mathrm{C}}_2{\mathrm{H}}_5\mathrm{ONa},{\mathrm{C}}_2{\mathrm{H}}_5\mathrm{Cl}$

   

Q 14 :

The compound ${\mathrm{C}}_7{\mathrm{H}}_8$undergoes the following reactions:

${\mathrm{C}}_7{\mathrm{H}}_8\stackrel{3{\mathrm{Cl}}_2/∆}{\to }\mathrm{A}\stackrel{{\mathrm{Br}}_2/\mathrm{Fe}}{\to }$$\mathrm{B}\stackrel{\mathrm{Zn}/\mathrm{HCl}}{\to }\mathrm{C}$

The product C is                                               [2018]

• $m$-bromotoluene

   

• $o$-bromotoluene

   

• 3-bromo-2,4,6-trichlorotoluene

   

• $p$-bromotoluene

   

Q 15 :

Identify A and predict the type of reaction.              [2017]

Q 16 :

Consider the reaction,

${\mathrm{CH}}_3{\mathrm{CH}}_2{\mathrm{CH}}_2\mathrm{Br}+\mathrm{NaCN}\to {\mathrm{CH}}_3{\mathrm{CH}}_2{\mathrm{CH}}_2\mathrm{CN}+\mathrm{NaBr}$

This reaction will be the fastest in                        [2016]

• ethanol

   

• methanol

   

• N, N′-dimethylformamide (DMF)

   

• water

   

Q 17 :

Which of the following biphenyls is optically active?              [2016]

Q 18 :

For the following reactions:

Which of the following statements is correct?                [2016]

• (A) is elimination, (B) and (C) are substitution reactions.

   

• (A) is substitution, (B) and (C) are addition reactions.

   

• (A) and (B) are elimination reactions and (C) is addition reaction.

   

• (A) is elimination, (B) is substitution and (C) is addition reaction.

   

Q 19 :

Two possible stereo-structures of ${\mathrm{CH}}_3\mathrm{CHOHCOOH}$, which are optically active, are called            [2015]

• atropisomers

   

• enantiomers

   

• mesomers

   

• diastereomers

   

Q 20 :

In an ${\mathrm{S}}_{\mathrm{N}}1$ reaction on chiral centres, there is              [2015]

• inversion more than retention leading to partial racemisation

   

• 100% retention

   

• 100% inversion

   

• 100% racemisation