Q 1 :

The correct stability order of carbocation is                         [2024]

• ${\left({\mathrm{CH}}_3\right)}_3{\mathrm{C}}^{+}>{\mathrm{CH}}_3-\stackrel{+}{\mathrm{C}}{\mathrm{H}}_2>{\left({\mathrm{CH}}_3\right)}_2\stackrel{+}{\mathrm{C}}\mathrm{H}>\stackrel{+}{\mathrm{C}}{\mathrm{H}}_3$

   

• $\stackrel{+}{\mathrm{C}}{\mathrm{H}}_3>{\left({\mathrm{CH}}_3\right)}_2\stackrel{+}{\mathrm{C}}\mathrm{H}>{\mathrm{CH}}_3-\stackrel{+}{\mathrm{C}}{\mathrm{H}}_2>{\left({\mathrm{CH}}_3\right)}_3\stackrel{+}{\mathrm{C}}$

   

• ${\left({\mathrm{CH}}_3\right)}_3\stackrel{+}{\mathrm{C}}>{\left({\mathrm{CH}}_3\right)}_2\stackrel{+}{\mathrm{C}}\mathrm{H}>{\mathrm{CH}}_3-\stackrel{+}{\mathrm{C}}{\mathrm{H}}_2>\stackrel{+}{\mathrm{C}}{\mathrm{H}}_3$

   

• $\stackrel{+}{\mathrm{C}}{\mathrm{H}}_3>{\mathrm{CH}}_3-\stackrel{+}{\mathrm{C}}{\mathrm{H}}_2>{\mathrm{CH}}_3-\underset{\stackrel{|}{{\mathrm{CH}}_3}}{\overset{+}{\mathrm{CH}}}>{\left({\mathrm{CH}}_3\right)}_3{\mathrm{C}}^{+}$

   

Q 2 :

A species having carbon with sextet of electrons and can act as electrophile is called                 [2024]

• pentavalent carbon

   

• carbon free radical

   

• carbocation  

   

• carbanion

   

Q 3 :

Correct order of stability of carbanion is                          [2024]

• d > a > c > b

   

• d > c > b > a

   

• a > b > c > d

   

• c > b > d > a

   

Q 4 :

The shape of carbocation is:                         [2024]

• tetrahedral

   

• trigonal planar

   

• diagonal pyramidal

   

• diagonal

   

Q 5 :

Number of carbocation from the following that are not stabilized by hyperconjugation is……….                 [2024]

Q 6 :

Which one of the carbocations from the following is most stable?                       [2025]

Q 7 :

The correct order of stability of following carbocations is:                      [2025]

• C > A > B > D

   

• B > C > A > D

   

• C > B > A > D

   

• A > B > C > D

   

Q 8 :

Which among the following halides will generate the most stable carbocation in the nucleophilic substitution reaction?            [2025]

Q 9 :

The most stable carbocation from the following is:                         [2025]

Q 10 :

The correct stability order of the following species/molecules is:                   [2025]

• $p>q>r$

   

• $q>p>r$

   

• $q>r>p$

   

• $r>q>d$

   

Q 11 :

Consider the following compound (X)

The most stable and least stable carbon radicals, respectively, produced by homolytic cleavage of corresponding C–H bond are:          [2025]

• II, IV

   

• III, II

   

• I, IV

   

• II, I

   

Q 12 :

In which pairs, the first ion is more stable than the second?                  [2025]

• (B) and (D) only

   

• (A) and (B) only

   

• (B) and (C) only

   

• (A) and (C) only

   

Q 13 :

Match the LIST-I with LIST-II                          [2025]

	List-I		List-II
A.	Carbocation	I.	Species that can supply a pair of electrons
B.	C-Free radical	II.	Species that can receive a pair of electrons.
C.	Nucleophile	III.	$s{p}^2$ hybridized carbon with empty $p$-orbital.
D.	Electrophile	IV.	$s{p}^2/s{p}^3$ hybridized carbon with one unpaired electron.

 

Choose the correct answer from the options given below:

• A-IV, B-II, C-III, D-I

   

• A-II, B-III, C-I, D-IV

   

• A-III, B-IV, C-II, D-I

   

• A-III, B-IV, C-I, D-II

   

Q 14 :

Designate whether each of the following compounds is aromatic or not aromatic.              [2025]

• e, g aromatic and a, b, c, d, f, h not aromatic

   

• b, e, f, g aromatic and a, c, d, h not aromatic

   

• a, b, c, d aromatic and e, f, g, h not aromatic

   

• a, c, d, e, h aromatic and b, f, g not aromatic

   

Q 15 :

The most stable carbocation for the following is:                        [2023]

• c

   

• d

   

• b

   

• a

   

Q 16 :

The decreasing order of hydride affinity for following carbocations is:            [2023]

Choose the correct answer from the options given below:

• A, C, D, B

   

• A, C, B, D

   

• C, A, D, B

   

• C, A, B, D

   

Q 17 :

Given below are two statements:

Statement I: ‘C–Cl’ bond is stronger in ${\mathrm{CH}}_2$ = CH–Cl than ${\mathrm{CH}}_3$–${\mathrm{CH}}_2$–Cl.

Statement II: The given optically active molecule,  on hydrolysis gives a solution that can rotate the plane polarized light.

In the light of the above statements, choose the correct answer from the options given below:                [2026]

• Both Statement I and Statement II are false

   

• Statement I is true but Statement II is false

   

• Statement I is false but Statement II is true

   

• Both Statement I and Statement II are true

   

Q 18 :

Arrange the following carbanions in the decreasing order of stability.

Choose the correct answer from the options given below:                   [2026]

• IV > I > II > V > III

   

• I > IV > II > V > III

   

• IV > II > I > III > V

   

• I > II > IV > V > III

   

Q 19 :

From the following, the least stable structure is:   [2026]

Q 20 :

The correct order of the rate of reaction of the following reactants with nucleophile by ${\mathrm{S}}_{\mathrm{N}}1$ mechanism is:

(Given: Structures I and II are rigid)                               [2026]

• IV < III < II < I

   

• II < I < III < IV

   

• I < II < III < IV

   

• III < I < II < IV

   

Q 21 :

Correct order of stability for the following is
${\mathrm{CH}}_2={\mathrm{CH}}^{-},{\mathrm{CH}}_3-{\mathrm{CH}}_2^{-},\mathrm{CH}\equiv {\mathrm{C}}^{-}$       [2026]

• $\mathrm{CH}\equiv {\mathrm{C}}^{-}>{\mathrm{CH}}_2={\mathrm{CH}}^{-}>{\mathrm{CH}}_3-\mathrm{C}{{\mathrm{H}}_2}^{-}$

   

• $\mathrm{CH}\equiv {\mathrm{C}}^{-}>{\mathrm{CH}}_3-{\mathrm{CH}}_2^{-}>{\mathrm{CH}}_2={\mathrm{CH}}^{-}$

   

• ${\mathrm{CH}}_2={\mathrm{CH}}^{-}>\mathrm{CH}\equiv {\mathrm{C}}^{-}>{\mathrm{CH}}_3-{\mathrm{CH}}_2^{-}$

   

• ${\mathrm{CH}}_3-\mathrm{C}{{\mathrm{H}}_2}^{-}>{\mathrm{CH}}_2={\mathrm{CH}}^{-}>\mathrm{CH}\equiv {\mathrm{C}}^{-}$