1 . Carbanion is a :-

(A) Base (B) Nucleophile (C) Both (A) and (B) (D) None

2 . Electrophile is :

(A) H2O (B) NH

3(C) AlCl

3(D) C

2H

5NH

2

3 . Which of the following species has a pyramidal shape-

(A) CH3

+ (B) BF3

(C) CH3

– (D) 3CH

4 . Increasing order (least basic first) of basic strength is shown by the set

(A) ClNH2, NH

3, CH

3NH

2(B) ClNH

2, CH

3NH

2, NH

3

(C) NH3, ClNH

2, CH

3NH

2(D) CH

3NH

2, ClNH

2, NH

3

5 . The decreasing order of acid strength indicated by the following sequence of reaction is :-

–C–H –C–NaNaNH2 CH2 2

H2OHC CNa+ PhCH3 HC CH + NaOH

(A) NH3

> Ph3CH > C

2H

2 > H

2O (B) H

2O > HC CH > Ph

3CH > NH

3

(C) HC CH > H2O > Ph

3CH > NH

3(D) Ph

3CH > HC CH > H

2O > NH

3

6 . In which of the following compounds is hydroxylic proton the most acidic -

(A) OF

H(B)

OI

H(C)

O

HF

(D)

O

HF

7 . Correct arrangement of the following acids in correct Ka order is :-

(I) H3N—CH2—COOH (II) NC—CH2—COOH (III) H3C—CH2—COOH (IV) OOC

—CH2—COOH

(A) I > II > III > IV (B) II > I > III > IV (C) I > III > II > IV (D) IV > III > II > I

8 . Which of the following orders of acid strength is correct :-

(A) RCOOH > ROH > HOH > HC CH (B) RCOOH > HOH > ROH > HC CH

(C) RCOOH > HOH > HC CH > ROH (D) RCOOH > HC CH > HOH > ROH

9 . Which of them is false for order of – I effect

(A) –F > –Cl > –Br > I (B) –NR > –NH > –NO3 3 2

(C) –OCH3 > –OH > –NH

2(D) > –C CH

> H

1 0 . The order of basicity of halides is :

(A) Cl– < Br– < I

– < F

–(B) F

– < I

– < Br– < Cl

–

(C) I – < Br– < Cl

– < F

–(D) Cl

– < F

– < I

– < Br–

EXERCISE-01 CHECK YOUR GRASP

SELECT THE CORRECT ALTERNATIVE (ONLY ONE CORRECT ANSWER)

1 1 . Which of the following molecule has longest C=C bond length -

(A) CH2=C=CH

2(B) CH

3–CH=CH

2

(C) CH–C–CH=CH3 2

CH3

CH3

(D) CH–C=CH3 2

CH3

1 2 . In the reaction CH3CN 3H O

heat

CH

3COOH

the hybridization state of the functional carbon changes from

(A) sp3 to sp2 (B) sp2 to sp3 (C) sp to sp2 (D) sp2 to sp

1 3 . Most stable carbocation is :-

(A)

CH2

Cl

(B)

CH2

NO2

(C)

CH2

OCH3

(D)

CH2

1 4 . Most stable carbanion is :-

(A) HC C (B) C6H

5 (C) (CH

3)3C—CH

2 (D) (CH

3)2C CH

1 5 . Consider the following carbocations

(a) –CH2CHO3 –

(b) –CH2

(c) –CH2CH3–

(d) CH

3— 2C H

The relative stabilities of these carbocations are such that :-

(A) d < b < c < a (B) b < d < c < a

(C) d < b < a < c (D) b < d < a < c

1 6 . Among the following, the strongest base is :-

(A) C6H

5NH

2(B) p–NO

2–C

6H

4NH

2(C) m–NO

2–C

6H

4NH

2(D) C

6H

5CH

2NH

2

1 7 . The increasing order of base strength of Cl–, CH3COO–, —OH and F— is :

(A) Cl– < F— < CH3COO– < —OH (B) Cl– > F— > CH

3COO– > —OH

(C) CH3COO– < Cl– < F— < —OH (D) None of these

1 8 . Formic acid is considered as a hybrid of the four structures

H–C

O

–OH H–C

O

= OH

H–C–O–H

O

H–C–O–H

O

I II III IV

Which of the following order is correct for the stability of the four contributing structures.

(A) I > II > III > IV (B) I > II > IV > III (C) I > III > II > IV (D) I > IV > III > II

1 9 . Which of the following carbonium ion is most stable

(A) Ph3C+ (B) (CH

3)3 C+ (C) (CH

3)2 CH+ (D) CH

2CH—CH

2+

2 0 . Among the following the aromatic compound is

(A)

(B)

(C) (D)

2 1 . Match List- I with List- II and select the correct answer using the codes given below -

List- I (Stabi l i ty ) List - I I (Reason)

(A)

CH3C CH3

> CH3+ (1) Inductive effect

(B)

Br

CH3

HC–C3

< CH3– (2) Resonance

(C)CH3

HC–C3

CH3

> H3C–CH

2+ (3) Hyperconjugation and resonance

(D)CH2

•

> CH2

•H3C

CH3(4) Hyperconjugation and inductive effect

Codes :

(A) A - 2 ; B - 3 ; C - 4 ; D - 1 (B) A - 3 ; B - 1 ; C - 4 ; D -2

(C) A - 4 ; B - 3 ; C - 1 ; D - 2 (D) A - 3 ; B - 4 ; C - 2 ; D - 1

2 2 . Which of the following compounds is the strongest base -

(A) NH2 (B) NH2 (C) NH2CH3 (D) NHCOCH3

23. In which of the following molecule all the effect namely inductive, mesomeric & hyperconjugation operate:

(A) —Cl (B) —CH3

CH3

(C) —COCH3

CH3

(D)

2 4 . Which of the following reaction is possible :

(A) +

OH ONa

NO2

(B) CH–C–OH + HCOONa 3

O

(C) +

SONa3 COOH

(D) H–CC–Na+H2O

2 5 .

COOH

X

, pKa value of the compound decreases if X is :-

(A) –NO2

(B) –NH2

(C) –OH (D) –OCH3

2 6 . Which one of the following results most stable carbon free radical :

(A) CH3

•

(B) CH3

•

(C) (Ph)2C = C(Ph)

2 CH3

•

(D) CH2 = CH

2 CH3

•

2 7 .

CH – C CH3 2–

H

1,2 shiftA (Major) ; Here A is :

(A) CH – C – CH3 3

(B)

CH– CH 2

CH3

(C)CH – C – HC–3 2

H

(D)

Ph

CH – C = CH3 2

2 8 . –CHOH2 ; On dehydration with conc. H2SO

4 forms predominantly :

(A) =CH2 (B) –CH3 (C) –CH3 (D) –CH3

2 9 . Which of the following is incorrect :

(A)

CHCH2 3 CHCH3

Cl•

•

+ HCl (B)

O

HO – C – H + C – H HO – C– H + H – C – H

H H H

:OO O

(C) CH – C CH – C– CH3 3 2

H

H–CH2

CH3

H shift

H

(D) 3 2 3 2

–HOCH CH CHO CH C HCHO H O

3 0 . The Ka values of alcohols, water and phenol are of order 10–17, 10–14 and 10–10 respectively. Which of the

following reactions is possible :

(I) C6H

5O + H

2O C

6H

5OH + OH (II) C

2H

5O + H

2O C

6H

5OH + OH

(A) Both I and II (B) only II (C) only I (D) neither of two

3 1 . Most stable carbanion is :

(A) 3CH (B) 2 2CH CH – CH

(C)

CH2

(D)

CH2

NO2

3 2 . Stability of :

(I) CH3–CH=CH–CH

3(II) CH– C = C – CH3 3

CH3

CH3

(III) CH– C = CH3 2

CH3

(IV) CH– C = CH – CH3 3

CH3

in the increasing order is :

(A) I < III < IV < II (B) I < II < III < IV (C) I < IV < III < I (D) II < III < IV < I

3 3 .HO2 [A]–MgBr + CH—CH2 2

O

; the product (A) is :

(A) –CHOH2 (B) –CH OH2CH2

(C) —CH—CH2

O

(D) No reaction

3 4 . Spin multiplicity of Triplet nitrene is :

(A) 1 (B) 2 (C) 3 (D) 4

3 5 . The maximum probability of proton loss is in the case of :

(A) 3 2CH – CH

(B) CH C – CH3 3–

CH3

(C) H

H

(D) (CH) C – CH3 2 2

H

3 6 . Select the least stable one :

(A) CH – CH3 2

(B) CH – CH – CH3 2 2

(C) CH– CH 2

HC3

HC3(D) C – CH 2

HC3

HC3

HC3

3 7 . Which of the following will react fastest with conc. HCl :

(A) –CH OH2CH2 (B) –CH H3(OH)C

(C) –OH (D) –CH2OH

3 8 . Consider the following reaction :

+ NaNH2Product

Br

OCH3

The product (P) and reaction (R) are :

(A)

OCH3

NH2

; addition-elimination (B)

OCH3

NH2

; elimination addition

(C)

OCH3

NH2

; elimination addition (D)

OCH3

NH2

; cine substitution

3 9 . Energy of activation is lower for which reaction :

(A) 2 2 2RCH OH R C H

(B) 2 2 2R CH OH R CH

(C) 3 2 3R C OH R C

(D) all have same Eact.

CHECK YOUR GRASP EXERCISE -1ANSWER KEYQ u e . 1 2 3 4 5 6 7 8 9 1 0 1 1 1 2 1 3 1 4 1 5

A n s . C C C A B D A B D C D C C A A

Q u e . 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 2 6 2 7 2 8 2 9 3 0

A n s . D A A A A B B C D A C A B C B

Q u e . 3 1 3 2 3 3 3 4 3 5 3 6 3 7 3 8 3 9

A n s . D A B C C D B C C

1 . The correct order of decreasing basic strength is :

N

H

N

H

N

NH2

I II III IV

(A) I > II > III > IV (B) II > III > I > IV (C) II > IV > I > III (D) II > III > IV > I

2 . The correct order of increasing dissociation constant of the following compound is :-

OH

NO2

NO2

OH

NO2

OH

NO2NO2

NO2

OH

NO2

I II III IV

(A) II < IV < I < III (B) IV < III < I < II (C) IV < II < I < III (D) IV < I < II < III

3 . In the following arrange the H (numbered) for their ease of displacement during acid base reaction :

HOOH

2 equivalentH(1)

(3)

NaNH(liquid NH)2 3

(2)

(A) 1 > 2 > 3 (B) 3 > 2 > 1 (C) 3 > 1 > 2 (D) 2 > 3 > 1

4 . Which one of the following is the strongest base in aqueous medium :-

(A) (C2H5)3N (B) C2H5NH2 (C) NH3 (D) (C2H5)2NH

5 . The correct order of acid strength of the following compound is -

(I) CH–C–CH3 3

O

(II) CH–C– CH3 3C–

O O

(III) CH–C– CH3 3CH–C–2

O O

(A) III > II > I (B) III > I > II (C) II > I > III (D) I > II > III

6. Which of the following shows the correct order of decreasing basicity in aqueous medium -

(A) (CH3)3 N > (CH3)2NH > CH3NH2 > NH3 (B) (CH3)2 NH > (CH3)3N > CH3NH2 > NH3

(C) (CH3)2 NH > CH3NH2 > (CH3)3N > NH3 (D) (CH3)2 NH > CH3NH2 > NH3 > (CH3)3N

7 . For the compounds

N N N

O

H HI II III

the order of basicity is -

(A) III > II > I (B) II > III > I (C) I > II > III (D) II > I > III

EXERCISE–02 BRAIN TEASERS

SELECT THE CORRECT ALTERNATIVES (ONE OR MORE THEN ONE CORRECT ANSWERS)

8 . Which of the following shows the correct order of decreasing acidity-

(A) PhCO2H > PhSO3H > PhCH2OH > PhOH

(B) PhSO3H > PhOH > PhCO2H > PhCH2OH

(C) PhCO2H > PhOH > PhCH2OH > PhSO3H

(D) PhSO3H > PhCO2H > PhOH > PhCH2OH

79 . Give the correct order of increasing acidity of the following compounds-

OH OH COOH C CH

I II III IV

(A) II < I < III < IV (B) IV < II < I < III (C) I < II < IV < III (D) IV < I < II < III

1 0 . Which of the following is the most acidic

(A) CH2 = CH2 (B) HC CH

(C) CH2=CHCH2CH=CH2 (D)

1 1 . Which of the following substituents will increase the acidity of phenol -

(A) –NO2 (B) –CN (C) –CHO (D) – CH3

1 2 . (I) (II) (III)

Compare carbon-carbon bond rotation across I, II, III.

(A) I > II > III (B) I > III > II (C) II > I > III (D) II > III > I

1 3 . Which of the following s-bonds participate in hyperconjugation :

I VHCH3H

HII

IIIIV

(A) I and II (B) I and V (C) I and V (D) III and IV

1 4 . NH

(x)

, N–H

O(y)

, N

(z)

The correct order of decreasing basic strengths of x, y and z is :

(A) x > y > z (B) x > z > y (C) y > x > z (D) y > z > x

1 5 . Set the following in increasing order of their aKp values:

(x) CH—S—O—H3

O

O

(y) CH—C—O—H3

O

(z) CH—OH3

(A) y > x > z (B) x < y < z (C) y > z > x (D) x < z < y

1 6 . Rank the following alkenes in order of decreasing heats of hydrogenation (largest first):

(I) (II) (III) (IV)

(A) II > III > IV > I (B) II > IV > III > I (C) I > III > IV > II (D) I > IV > III > II

1 7 . Which of the following molecules has all the effects : inductive, mesomeric and Baker Nathan effect ?

(A) C2H5Cl (B) CH3–CH=CH2

(C) CH2=CH–CH=CH2 (D) CH3–CH=CH –C–

O

CH3

1 8 . Which nitorgen in LSD (Lysergic acid diethylamide) is more basic :

H–NI

NII

–C–N(C H )2 5 2

OIII

CH3

(A) I (B) II (C) III (D) all are equally basic

1 9 . Which of the following substituted carboxylic acids has the highest Ka value :

(A) CH3—CH2—CH—

Cl

COOH (B) CH3 —CH—

Cl

CH2—COOH

(C) CH—2

Cl

CH2—CH2—COOH (D) CH3—CH—

Br

CH2—COOH

SELECT THE CORRECT ALTERNATIVES (ONE OR MORE THEN ONE CORRECT ANSWERS)

2 0 . Which of the following compounds yield most stable carbanion after rupture of (C1–C2) bond :

(A) CH CCl3 3—C—

O

1 2(B) CH CBr3 3—C—

O

1 2

(C) CH—CH CI3 2 3—C—

O

1 2(D) None of these

2 1 .N

Hpyrrole (I)

pyridine (II)

N

aniline (III)NH2

Which is/are correct statements ?

(A) I is more basic than II (B) II is more basic than I and III

(C) III is more basic than II (D) all are aromatic bases

2 2 . Following is true for stability between the two structures :

(A) CH–CH–CH=CH3 2

O

> CH–C=CH–CH3 3

O

(B) CH2=CH–CH=CH–CH2• > CH–C–CH–CH2 3

CH2

•

(C) CH=C–CH2 2

CH3

> CH3–CH=CH–2CH

(D) —O < CH–C–O3

O

2 3 . Which have acidic hydrogen :

(A) CH3COOH (B) —OH (C)

O

CH—C3 —CH—CN2 (D) NaNH2

2 4 . C—C and C=C bond lengths are unequal in :

(A) Benzene (B) 1,3 buta-di-ene

(C) 1, 3 cyclohexa-di-ene (D) None

2 5 . The acid strength of substituted carboxylic acids is known to be dependent on the nature and position of

the substituent. In the following examples, an attempt has been made to arrange the acids in order of acid

strength, the strongest first. One of the series is incorrect-which one :

(A) CH3.CH2CH(Cl).COOH > CH3 .CH(Cl).CH2COOH > CH3.CH2.CH2.COOH

(B) NO2.CH2.COOH > HOCH2. COOH > CH3.COOH

(C) Cl3C.COOH > BrCH2.COOH > FCH2.COOH

(D) CH3.COOH > CH3.CH2.COOH > (CH3)3C.COOH

2 6 . Which species is not aromatic :

(A)

N

(B) (C) NH (D)

N:

2 7 . Select the correct option :

(A) carbonic acid is weaker acid than acetic acid

(B) the boiling points of acids are higher than corresponding alcohols

(C) chloroacetic acid is stronger acid than acetic acid

(D) phenol is more acidic than ethanol

2 8 . Which reacts with AgNO3 to give ppt. :

(A) —Br (B) –CH=CH–CHBr2 (C)

—Br

(D) —Br

2 9 . Which statement is ture :

(A) NH2

– is stronger base than OH–

(B) NH2–OH is less basic than NH3

(C) CH3–NH2 is weaker base than N(CH3)3 in (aq) medium

(D)

NH2

is weaker base than

CH–2 NH2

3 0 . Which is less acidic than phenol :

(A)

OH

—CH 3 (B) CH3–OH (C)

OH

—NH 2(D) H2O

3 1 . The precursor carbocation to the product in the following reaction is :

OH H

CH6 5H

H

CH6 5

(A) CH6 5

(B) CH6 5 (C) either of the two (D) none of the two

3 2 . Which of the following ion is formed in the following reaction :

OH

H

O

(A)

OH

(B)

OH

(C) OH

CH2

(D) All of three

3 3 .

OD

D NaOH

CO2 D[Intermediate] P. Product is :

(A)

OD

DHOOC(B)

OD

DDOOC

(C)

OH

DDOOC(D) Reaction not possible

3 4 . Predict the nature of A in the following reaction :

+ ClCHCOOCH2 2 5Base

O

(A)

(A)CHCOOCH2 2 5

O

(B) CCOOCH2 5

Cl

(C) CHCOOCH2 5

O(D) CHCOOCH2 5

O

3 5 . Which of the following intermediate is most likely to be formed during addition of HBr on crotonic acid :

CH3CH = CHCOOH + HBr(g) CH3CH

Br

–CH2COOH :

(A)3 2CH CH – C HCOOH

(B) 3 2CH CH – CH COOH

(C) CHCH=CH–C–OH3

OH

(D) none of these

3 6 . Which will give most stable cation upon strong heating :

(A)

CH – Cl2

(B) (Ph)3C–Cl (C)

Cl

(D) CH

CH2

CH–Cl2

3 7 .

H

—Cl

Cl

(A); Here (A) is :

(A)

(B)

(C)

(D)

3 8 . Cl – C – C – F

F

Cl F

–F [X] ; Here [X] is :

(A) Cl – C = C – F

Cl F

(B) Cl – C = C – Cl

FF

(C) Cl – C = C – F

F

Cl F

F

(D) C l – C = C – F

3 9 .

HC3 CH3

H H

C CH

CH3

H

HC3 CHCl3KOH the reaction proceeds via :

(A) carbene (B) Carbon free radical (C) Carbocation (D) Carbanion

4 0 .:C

NH

• •

Cl

Cl (A) ; Here A is :

(A) N

(B) N

H

Cl

(C)

N

Cl

(D) N

Cl

4 1 . Which of the following can give benzyne :

(A) Cl

HNaNH2

(B) N2

(C) Cl

BrNaNH2

(D) All

4 2 . Dehydration of the following in increasing order is :

(I) –OH (II) –OH (III) –OH (IV) –OH

(A) I < II < III < IV (B) II < III < IV < I (C) I < III < IV < II (D) I < IV < II < III

4 3 . Increasing tendency for SN1 and SN2 reaction is :

(I) CH3CH2CH2CH2Cl (II) CHCHCH – CH3 2 3

Cl

(III)CHCHCH – Cl3 2

CH3

(IV) CH C – Cl3–

CH3

CH3

(A) SN1 ; I < I I I < I I < IV (B) SN2 ; IV < II < II I < I

(C) (A) and (B) both are correct (D) Both incorrect

4 4 . Cyclopentyl ethyl ether can be obtained by :

(A) –ONa+CHCHBr3 2 (B) –Br+CHCHONa3 2

(C) –OH+CHCHCl3 2 (D) none is correct

4 5 . Major product in the following reaction is :

–Br + KOCHCH2 3 Product

(A) –OCHCH2 3 (B) (C) —Br

OCHCH2 3

(D)

4 6 . Mechanism of insertion reaction is of :

(A) One step for triplet carbene (B) Two step for singlet carbene

(C) One step for singlet carbene (D) Two step for both

4 7 .

HC31

2

35

6

–Cl

NH2 (P)

4

. The most probable structure of intermediate P is :

(A)

OCH31

2

35

6

4

(B)

12

35

6

4

OCH3

(C)

OCH31

2

35

6

4

(D)

12

35

6

4

OCH3

4 8 .

CH31

2

35

6

–Cl

NH2 (A)

4

. The most probable structure of intermediate A is :

(A)

CH31

2

35

6

4

(B)

CH31

2

35

6

4

(C)

CH31

2

35

6

4

(D)

CH31

2

35

6

4

4 9 . Hybridisation of arrow headed 'C' is

(A) sp2 sp3 (B) sp3 sp3 (C) sp2 sp2 (D) sp3 sp3d

5 0 . Which of the following is most strongest electrophile :

(A) singlet H – N• •

•• (B) triplet H – N

• •

•• (C) singlet – C (D) triplet – C –

5 1 . In benzyne two external unshared electronic orbital :

(A) do not overlap to form a bond (B) can overlap to form a complete bond

(C) poorly overlap to form a very weak bond (D) contribute in benzene ring

5 2 . Which of the following is aromatic intermediate :

(A) carbene (B)

•

(C) Benzyne (D) •

•

5 3 . In which of the following case 'H' shift is more preferable than 'CH3' shift :

(A)

CH3

CH – C – CH3 2

H

(B)

CH3

CH – C – 3 CH – C – H

H

H

CH3

(C)

CH3

CH – C – 3 CH – CH3

Ph

(D) all

5 4 . Which of the following will not give 1, 2, shift :

(A) 3 3 2(CH ) C — CH

(B) (CH) C CH—CH3 3 2

Hg2

(C)

OH

(D) all

5 5 . Which of the following reactions is wrong :

(A) CHCHCHO3 2

OH

CH – CH – CHO3

(B)

CHCH2 3 CHCH3 + HClCl

•

•

(C)

O

HO – C – H + H – C – H HO – C– H + H – C – H

H H

O O O

(D) CH – C CH – CH – CH3 3 2

CH3

CH3

Hydrideshifting

CH3

5 6 . Methyl benzylic carbonium ion is the most stable one, hence it will react fastest consider the following

reaction :

CH3

HH

Br SN2+ OH (P) ; product (P) will be :

(A)CH3

HHO

H(B)

CH3

H

HO

H

(C)

CH3

H

OH

H

H(D)

CH3

H

OH

H

H

5 7 . Consider the following reaction -

R – CH = CH2+ IN3A , A is :

(A) R – CH – CHN2 3

I

(B) R – CH – CHI2

N3

(C) R – CH – CH2

N

I

(D) R – CH – CH

N

5 8 .1 BuOK+ CHBr3 product ; product will be :

(A) Br

Br (B) Br

BrBr

Br

(C)

Br

(D) Br

5 9 . HBr

CH2

major product will be :

(A)

Me

Br(B)

CHBr2

(C)

CHBr2

(D)

CH3

Br

6 0 .OO

CH3

CH3

OH

Product ; major product of the reaction can be :

(A)

O

(B)

O

(C)

O

(D)

O

6 1 . CH3COCH3 + BrCH2COOEt 2

( i ) Zn

( ii ) H O / H (A) ; the product (A) is :

(A) CH3

COCH3

Br

CH3(B)

OH

CH3

CH–C–CHCOOEt3 2

(C) CH3

COH

COOEt

CH3(D)

CH3

CBr

OCHCOOEt2CH3

6 2 . Which carbocation is more likely to be formed in the dehydration of

OH

H :

(A)

(B)

(C)

(D)

6 3 . The most probable structure for (P) in the following reaction is :

2 conc HSO2 4 (P)

(A) (B) (C) (D)

6 4 . Which of the following alcohols is dehydrated most readily with conc. H2SO4 ?

(A)

CHOHCH3

(B)

CHOHCH3

OCH3

(C)

CHOHCH3

NO2

(D)

CHOHCH3

Cl

6 5 . Dehydration of alcohols by conc. H2SO4 takes palce according to following steps :

CH–C–CHOH3 2 CH–C–CHOH3 2 2

CH–C–CH3 3 CH=C–CH2 3

CH3 CH3

CH3 CH3

H H

H• •

• • step -I

–HO2step -II CH–C–CH3 2

CH3

H

1,2–H shift –H

step -III step -IV

the slowest and fastest steps in the above reaction are :

(A) step I is slowest, while III is fastest

(B) step II is slowest, while III is fastest

(C) step II is slowest, while IV is fastest

(D) all step proceed at equal rate

6 6 . Pyrrole is treated with alkaline chloroform to form two products A and B ?

KOH

N NH H

+ CHCl3CHO

+Cl

(A) (B)

N

Which of the following intermediate is likely to be formed ?

(I) N

H

CCl2 (II)

N

H

(III) N• •

CCl

Cl (IV) N

(A) I and IV (B) I and III (C) III and IV (D) I, III and IV

6 7 .conc. HSO2 4

OH

Major product is :

(A) (B) (C) (D)

BRAIN TEASERS EXERCISE -2ANSWER KEYQ u e . 1 2 3 4 5 6 7 8 9 1 0 1 1 1 2 1 3 1 4 1 5

An s . D C B D A C D D B D A,B,C C B B B

Q u e . 16 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 2 6 2 7 2 8 2 9 3 0

An s . D D B A A B,D A ,C A,B,C C C B A,B,C ,D B,D A,D A ,B,D

Q u e . 31 3 2 3 3 3 4 3 5 3 6 3 7 3 8 3 9 4 0 4 1 4 2 4 3 4 4 4 5

An s . A B C D C C C A A D D A A A B

Q u e . 46 4 7 4 8 4 9 5 0 5 1 5 2 5 3 5 4 5 5 5 6 5 7 5 8 5 9 6 0

An s . C A B C B C C A B D A B C A B

Q u e . 61 6 2 6 3 6 4 6 5 6 6 6 7

An s . B C C B C B C

TRUE OR FALSE :

1 . In benzene, carbon uses all the three p-orbitals for hybridization.

2 . All the carbon atoms in bicyclbutane are sp2-hybridized.

3 . Allene (CH2=C=CH

2) is a planar molecule.

4 . The greater stability of trans-but-2-ene over cis-but-2-ene can be explained on the basis of hyperconjugation

effect.

5 . In a two step reaction, the rate determining step has the lowest energy of activation.

FILL IN THE BLANKS :

1 . Out of benzene, ethylene and acetylene, the carbon-carbon bond is longest in ...................... .

2 . The cyclopentadienyl cation is ...................... while cyclopentadienyl anion is ............... .

3 . The type of delocalization involving sigma bond orbitals with bond or vacant orbital is called ..............

4 . Hydroperoxide ion is a stronger ...................... but weaker ................... than hydroxide ion.

5 . Catalytic hydrogenation of cis-2, 3-diphenyl-2-butene gives..................... .

MATCH THE COLUMN

1 . Match the column I with column II.

Co l umn - I Co l umn - I I

( A ) — N O2

( p ) – m effect

( B ) — O – ( q ) + m effect

( C ) — O — C H3

( r ) + I effect

( D ) —C N ( s ) – I effect

2 . Match the column I with column II.

Co l umn - I Co l umn - I I

( A ) ( p ) Aromatic

( B ) ( q ) Non-aromatic

( C ) + ( r ) Anti-aromatic

( D ) ( s ) Aliphatic

EXERCISE–03 MISCELLANEOUS TYPE QUESTIONS

3 . Observe the following compound P and match the column I with column II.

HOOC

HO

SOH3

C CH

Co lumn - I Co l umn - I I

( A ) Strongest acidic group in P ( p ) 1

( B ) Weakest acidic group in P ( q ) 2

( C ) Number of Intra molecular ( r ) 3

H-Bonding in P

( D ) Number of mole of hydrogen ( s ) 4

gas that is liberated on reaction

of 'P' with excess of sodium metal if

one mole of P is used

ASSERTION & REASON QUESTION :

These questions contains, Statement-I (assertion) and Statement-II (reason).

(A) Statement-I is True, Statement-II is True ; Statement-II is a correct explanation for Statement-I

(B) Statement-I is True, Statement-II is True ; Statement-II is NOT a correct explanation for Statement-I

(C) Statement-I is True, Statement-II is False.

(D) Statement-I is False, Statement-II is True.

1 . Statement-I : Greater the s-character of the hybrid orbital, the smaller is its size.

B e c au s e

Statement-II : Bond formed by the overlap of sp3-sp3 hybrid orbital is the longest while the bond formed

by the overlap of sp-sp hybrid orbital is shortest.

2 . Statement-I : 3Me C

is more stable than 2Me C H

and 2Me C H

is more stable than the 2Me C H

.

B e c au s e

Statement-II : Greater the number of hyperconjugative structures, more is the stability of carbocation.

3 . Statement-I : Cyclopentadienyl anion is much more stable than allyl anion.

B e c au s e

Statement-II : Cyclopentadienyl anion is aromatic in nature.

4 . Statement-I : CH3OCH3 and C2H5OH have comparable molecular masses but boiling point of C2H5OH

is higher than dimethyl ether.

B e c au s e

Statement-II : C2H5OH forms intermolecular H-bonding while CH3OCH3 forms intramolecular H-bonding.

5 . Statement-I : In the compound, IV III II I

23C H — C H — C N , the most electroegative carbon is II.

B e c au s e

Statement- II : Carbon atom II has more s-character.

6 . Statement-I : pka1 of fumaric acid is more than maleic acid.

B e c au s e

Statement-II : Conjugate base of fumaric acid is stabilised by intramolecular H-bonding.

7 . Statement-I : Carbocation (II) is more stable than carbocation (I)

CH2

CH3

(I)

CH2

CD3

(II)

B e c au s e

Statement-II : Carbocation (II) has more positive inductive effect of –CD3 group as compared to –CH3

group.

8 . Statement-I : Carbon-oxygen bonds are of equal length in acetate ion.

B e c au s e

Statement-II : Bond length decreases with the multiplicity of bond between two atoms.

9 . Statement-I : The potential energy barrier for rotation about C=C bond in 2-butene is much higher than

that in ethylene.

B e c au s e

Statement-II : Hyperconjugat ion effect decreases the double bond character.

1 0 . Statement-I : Pyrrolidine (II) is more basic than pyrrole (I).

N

H

• •

(I)

N

H

• •

(II)

B e c au s e

Statement-II : Protonated pyrrole has resonance stabilization of posit ive charge in aromatic ring.

COMPREHENSION BASED QUESTIONS :

Comprehension # 1

The intramolecular delocalisation of and /non-bonding electrons without any change in the position of

atoms is called resonance. Delocalisation may occur in conjugated system involving carbon atom and atom

other than the carbon. Delocalisation makes system stable. More is the number of resonating structures,

more is the stability of the system. A conjugated structure is least stable when a higher electronegative atom

has positive charge and when identical charges are present on adjacent atoms.

1 . The decreasing order of stability of the following resonating structures :

CH=CH—Cl CH—CH=Cl CH—CH= Cl 2 2 2 • • • •+– + –

(I) (II) (III)

is -

(A) I > II > III (B) II > III > I (C) III > II > I (D) I > III > II

2 . If A is Ph 2CH

and B is CH2=CH— 2CH

, the greater number of resonating structure is of -

(A) A (B) B (C) both A and B (D) None of these

3 . Which of the following pairs represent resonance ?

(A) CH2=CHOH ; CH3CHO (B) –

2C H –CHO ; H2C=CH–OH

(C) CH—C—CH3 3

O

; CH—C—CH3 2

OH

(D) CH—C—CH3 3

OH

; CH—C—CH3 3

OH+

H

4 . Examine the structures I and II for nitromethane and choose the statement correctly :

CH—N3 CH—N3

— ——

• • • • –O O

• • • •– –O O

(I) (II)

+ +2

• •

(A) II is less important because electrons have shifted to oxygen

(B) II is less important because nitrogen has sextet of electrons

(C) II is acceptable and important structure

(D) none of these

5 . Examine the following two structures for pyrrole and choose the correct statement given below :

• •N

O

• •N

O(II)(I)

–

+

(A) II is not an acceptable resonating structure because carbonium ions is less stable than nitride ion

(B) II is not an acceptable resonating structure because there is charge separation

(C) II is not an acceptable resonating structure because nitrogen has ten valance electrons

(D) II is an acceptable resonating structure

6 . Delocalization of electrons increases molecular stability because :

(A) Potential energy of the molecule decreases

(B) Electron-nuclei attraction decreases

(C) Both (A) and (B)

(D) Electron-electron repulsion increases

Comprehension # 2

Carbocation is a group of atoms with positively charged carbon atom having six electrons in the valence

shell after sharing. Carbocations are formed in the heterolysis of a bond and are planar species. Stability of

carbocation is determined by inductive effect, hyperconjugation and resonance effect. Greater the number

of contributing structures, more is the stability of a Carbocation. Electron releasing groups (+I effect) increases

the stability of a carbocation whereas the electron withdrawing groups (–I effect) have an opposite effect.

1 . Which of the following is most stable carbocation ?

(A) 3C H

(B) 3 3CH — C H — CH

(C) 3 2CH — C H

(D) CH—C—CH3 3

+

CH3

2 . The most stable carbocation among the following :

(A) (B)

(C)

(D)

NO2

3 . In which of the following cases, the carbocation (I) is less stable than the carbocation (II) ?

(A) C6H5— 2C H

(I ), CH2= CH— 2C H

( II) (B)

CH2

+

(I),

CH2

+

(II)

(C) CH2= C H

(I), CH3— 2C H

(II) (D) H3C— 2C H

(I), CH—2 CH2

F

(II)

4 . The most stable and the least stable carbocation among

(I), CH2=CH— 2C H

(II), C6H5— 2C H

(III)

and 3 3CH — C H — CH

(IV) are respectively :

(A) II, I (B) III, IV (C) I, II (D) I, IV

5 . Most stable carbocation is formed by the heterolysis of :

(A) (CH3)3CBr (B) (C6H5)3CBr (C) (C6H5)2CHBr (D) C6H5CH2Br

Comprehension # 3

The most important condition for resonance to occur is that the involved atoms in resonating structure must

be coplanar or nearly coplanar for maximum delocalisation. If this condition does not fulfil, involved orbitals

cannot be parallel to each other and as a consequence delocalisation cannot occcur. Bulky groups present

on adjacent atoms inhibit the of orbitats. This phenomenon is known as steric inhibition of resonance.

Steric inhibition of resonance has profound effect on

(1) Physical properties (2) Acidity and basicity (3) Reactivity of organic compounds

1 . Arrange the following in the increasing order of basicity :

(I)

NH2

(II)

NH2

(III)

NH2

NO2

(IV)

NH2

NO2

(A) I > II > III > IV (B) IV > III > II > I (C) II > I > IV > III (D) I > IV > III > II

2 . Which of the following is most acidic :

(A)

COOH

CH3

(B)

COOH

NO2

(C)

COOH

CH3

(D)

COOH

3 . Consider the following two structures and choose the correct statements -

NOO

:

+

(I)

NOO

:

+

(II)

(A) carbon-nitrogen bond length structure I is greater than that in structure II

(B) carbon-nitrogen bond length in structure I is less than in structure II

(C) carbon-nitorogen bond length in both structure is same

(D) It can not be compared

4 . Arrange the following carbocation in the increasing order of stability :

CH2

CH3

(I)

CH2

(II)NO2

CH2

(III)

NO2

CH–CH3

CH3

CH–CH3

CH3

(A) I < II < III (B) II < III < I (C) III < II < I (D) III < I < II

Comprehension # 4

1-Butene (A) and 1,3-Butadiene (B) differ not only in the number of bonds, but (B) also has and bonds

at alternate positions. This type of the system is called conjugate system. Following are some of the conjugate

system.

CH=CH–C–H2 CH=CH–C–OH2

O O

acrolein acrylic acid benzene

in such systems, electron shifting takes place consecutively giving permanent polarity on the chain. This

type of -electron shift in the conjugate systems is called mesomeric effect or resonance.

Rule s for re sonance forms :

(i) Individual resonance forms are imaginary, not real

(ii) Resonance forms differ only in the placement of their electrons or nonbonding electrons.

(iii) Different resonance forms of a substance don't have to be equivalent.

(iv) Resonance forms must be valid Lewis structures and obey normal rules of valencey.

(v) The resonace hybrid is more stable than any individual resonance.

Rules for stabi l i ty :

(i) Structures with more covalent bonds are more stable than other structures.

(ii) Structures in which all of the atoms have a complete valence shell of electrons (i.e. the noble gas

structure) are especially stable and make large contribution to the hybrid.

(iii) Stability is decreased by an increase in charge separation.

(iv) Structure that carry negat ive charge on a more electronegat ive atom and posit ive charge on less

electronegative atom are comparatively more stable.

1 . In which of the following compound, resonance is not possible :

(A) 2 3CH CH – NMe

(B)

OH2

(C)

N:

(D)

O

2 . Which of the following statement is incorrect -

(A) In a resonance hybrid all the molecules are the same. A resonance hybrid cannot be expressed by any

single structure.

(B) The value of the resonance energy of any resonance hybrid is not an absolute value

(C) The energy of hybrid structures is always less than that of any resonating structure

(D) Only one individual resonating structure explains all characteristics of the molecule

3 . Choose the correct option about stability of resonating structure :

(A) Cl

:: :

> Cl

(B)

N

O

<

O

N

(C)

O

<

COO

(D) H–C–O

O

> CH–C–O3

O

Tr ue / Fa l se1. F 2. F 3. T 4. F 5. F

Fi l l i n the B lanks

1. benzene 2. antiaromatic, aromatic 3. hyperconjucation 4. nucleophile, base5. 2,3-diphenylbutane (optically inactive, meso)

Match the Co lumn

1. (A) p,s ; B q,r ; (C) q,s ; (D) p,s 2. (A) q ; (B) p ; (C) p ; (D) r3. (A) p ; (B) q ; (C) p ; (D) q

Asser t i on - Reason Ques t ions

1. B 2. A 3. A 4. C 5. A6. C 7. D 8. B 9. D 10. C

Comprehens ion Based Que st ions

Comprehens ion #1 : 1. (A) 2. (A) 3. (B) 4. (B) 5. (C) 6. (C)Comprehens ion #2 : 1. (D) 2. (C) 3. (C) 4. (D) 5. (B)Comprehens ion #3 : 1. (C) 2. (B) 3. (B) 4. (B)Comprehens ion #4 : 1. (A) 2. (D) 3. (C,D)

MISCELLANEOUS TYPE QUESTION EXERCISE -3ANSWER KEY

EXERCISE–04 [A] CONCEPTUAL SUBJECTIVE EXERCISE

1 . Rank the following amines in increasing basic nature :

(a)

N

H(I)

N

(II)

(III)

NH2NH2

(IV)

(b)

(I)

NH2

(II)

NH2

CH3

(III)

NH2

CH3

(IV)

NH2

CH3

CH2

(c)

(I)

NH2

(II)

N

(III)

N

H

2 . Rank the following intermediates according to the stability (most stable first).

(a) 3 2 2 2CH CH CH C H

, 3 2 3CH C HCH CH

, 3 2 2 3(CH ) C CH CH

, 3 3(CH ) C

(b)•

3 2 2 2CH CH CH C H , •

3 2 3CH C HCH CH , •

3 2 2 3(CH ) C CH CH , •

3 3(CH ) C

3 . Rank the following intermediates according to the stability (most stable first).

(a) —

3 2 2 2CH CH CH C H , —

3 2 3CH C HCH CH , —

3 2 2 3(CH ) C CH CH , —

3 3(CH ) C

(b) ••2CH , •

•3CH CH , ••6 5C H CH , •

•6 5 2C H C

4 . Show why the phenolate ion, C6H

5O–, has a greater resonance stabilization than phenol, C

6H

5OH.

5 . Is phenol a stronger acid than acetic acid. Explain your answer with proper reasoning.

6 . Arrange all these numbered H in order of their decreasing acidic strength.

OO

H

OH

H

H

2

4

3

1

H

7 . Between –C=C–F••

and –C=C-Cl••

which lone pair- p conjugation will be more preffered.

8 . Which is more acidic and why ?

OH OH

9 . Arrange the following compound in the correct order of acidity :

COOH

(I)

SOH3

(II)

OH

(III)

OH

(IV)

CH2

1 0 . Why a cation like

is not possible.

1 1 .H

O

O OH

(A) Product.

1 2 . CH2=CHCHO + C2H5MgBr 3H O

P ; Here P is :

1 3 . Within each set, select the compound which is more reactive in nucleophilic addition at carbonyl carbon :

(I) CH3COCH2CH2Br or CH3COCH2Br (II) CH3CHO or CH3COCH3

(III) CH3COCH3 or CH3–CO–CF3 (IV) PhCHO or CH3CHO

1 4 . Rank of the following compounds in increasing order of electrophilicity :

(I) H

O

FC3 (II) H

CH2

CH3(III)

NH

CH3 OH

1 5 . Arrange the followings in increasing order of reactivity towards nucleophile :

(A) HC – C – NH3 2

O

(I); C – C – ClH3

O

(II); C – C – OAcH3

O

(III); HC3 – C – OCH3

O

(IV)

(B) HC – C – Cl3

O

(I)

; CHCH3 2 – C – Cl

O

(II)

; (CH) CH3 2 – C – Cl

O

(III)

; (CH) C3 3 – C – Cl

O

(IV)

(C) CH3 – C – OCH3

O

(I); CH CH3 3 – C – OCH2

O

(II)

; HC3 – C – OCH3

O

(III)

1 6 . Suggest the product of the reactions :

(A) AlCl /3

CH – CH3 2

Cl

(B) AlCl3

CH – C = O3

Cl

(C) CH – C – Cl3

CH3

CH3

KOH/Alc.(D) CH=CH–CH=CH2 2

HBr

40°C

–80°C

A

B

(E)

O – C –CH3

AlCl3

O

E (F)

OH

+ CO + HClAlCl3 G

(G) CH – CH – CH – CH3 2 3

N (CH)3 3

OH

H (H)

O

C ClO

AlCl3

1 7 . Arrange the following in increasing order of basic character :

(A) Cl, H2O, Br, H2S

(B)

NH2

,

NH2

CH3 CH3

,

CH–3 N–CH3

CH3 CH3

,

CH–N CH3 3–

(C)

NH2

F

,

NH2

F

,

NH2

Cl

,

NH2

Cl

(D)

C–O

O

;

C=O

O

OH

;

O–H

CO

O

O–H

;

CO

NO2OH

O

1 8 . Heat of hydrogenation of CH2=CH2 is greater than CH3–CH=CH2. Why ?

1 9 . In the case of CH – CH – CH – CH3 2 3

N(CH)3 3

OH, less stable 1-Butene is obtained. Why ?

2 0 . When carbene attacks cis 2-butene singlet gives cis product while triplet gives trans product. Why ?

1 . (a) I > III > II > IV (b) IV > III > II > I (c) II > I > III

2 . (a) 3 3(CH ) C

> 3 2 2 3(CH ) C CH CH

> 3 2 3CH C HCH CH

> 3 2 2 2CH CH CH C H

(b) •

3 3(CH ) C > •

3 2 2 3(CH ) C CH CH >•

3 2 3CH C HCH CH > •

3 2 2 2CH CH CH C H

3 . (a) —

3 2 2 2CH CH CH C H > —

3 2 3CH C HCH CH > —

3 2 2 3(CH ) C CH CH > —

3 3(CH ) C

(b) ••6 5 2

C H C > ••6 5C H CH > •

•3CH CH > ••2CH

4 . Free charge has move reactivity than bound charge.

5 . No

Anion of acetic acid is more stabilised by resonance than phenoxide ion.

6 . 4 > 3 > 2 >1

7 . In –C=C–F••

, lone pair - p conjugation will be more due to more overlaping of orbitals involved in conjugation.

8 . Phenol is more acidic as after loss of H+, phenoxide ion is Resonance stabilised. No such resonance is seen

in conjugate base of cyclohexanol.

9 . II > I > III > IV

1 0 . Due to the non-planar structure.

1 1 .

O

12. CH=CH– C – CH2 2 5

H

OH

CONCEPTUAL SUBJECTIVE EXERCISE EXERCISE -4 (A)ANSWER KEY

EXERCISE–04 [B] BRAIN STORMING SUBJECTIVE EXERCISE

1 . Rank the following sets of intermediates in increasing order of their stability giving appropriate reasons

for your choice.

(a) CH , C(C H ) , 2 56 2 3CHCH , ••

••

•• C HCH 56

••, •

•O2 2NCHCH

(b)

+

O +

O

+

O

+O

+

OO

(c)

O

CH—C2 —CH3,

O

CH—C2 —H,

O

CH—C2 —NH2 ,

O

CH—C2 —CH—OCH2 3

2 . For the following compounds, arrange the labelled proton in increasing order of their ease of

deprotonation :

(i)

C C—H3

H2

CH2

H1

(ii)

H3

O

OH

1

CCH2

OH

2

3 . Benzene sulphonic acid is a stronger acid than benzoic acid, explain.

4 . Which is a stronger acid, A or B and why ?

(I)

COOH

NO2

(A)

COOH

NO2

(B)

(II)

HH

ClCl

C–OH

O

(A)

HH

Cl

Cl

C–OH

O

(B)

5 . Descuss the following observations :

(a) C—Cl bond in vinyl chloride is stronger than in chloroethane.

(b) Carbon-carbon bond length in ethene is shorter than in CH2= CHOCH

3.

(c) CH3SH is stronger acid than CH

3OH.

(d) CH3CH

2NH

2 is stronger base than CH

2=CHNH

2.

6 . Discuss the basic strength of two nitrogens in benzimidazole.

N

N

HBenzimidazole

7 . In each of the following pair of compounds, which is more basic in aqueous solution ? Give an explaination

for your choice :

(i) CH3NH

2 or CF

3NH

2(ii) CH

3CONH

2 or H2N NH2

NH

(iii ) PhNH2 or CH

3CN

8 . Answer the following questions :

(i) Which of the indicated H is abstracted rapidly by bromine radical and why ?

Ph Hc

Hb

Ha

(ii) One of the indicated proton Ha or H

b, is approximately 1030 times more acidic than other, which is

more acidic and why ?

Ha

H

Hb

H

9 . Explain the following

(i) NC—CH2—CN is a stronger acid than CH

3—CO—C

2H

5.

(ii) CH3—CO—C

2H

5 is more acidic than CH

3—CH=CH

2.

(iii) CH3—CH=CH—OH is more acidic than CH

2=CH—CH

2—OH.

1 0 . Compare the bond dissociation energies of C—H bonds in the following

(i) H—CH2—CH

2—CH

2—CH

3 (ii )

HC3

H

CH3 (i i i ) (CH3)3C—H

1 1 . The most stable intermediatry carbocation and major product in following reactions :

(i)H

OH

[C ] Product

(ii) H

OH

[C ] Product

(iii)HBr

OH

[C ]O Product

1 2 . Which one of the following is more basic and why ?

(a)

(I)

N

(II)

–N• • CH3

CH3(b)

N

N

• •

CH3

1

2

• •

1 3 . Find the product in following reaction :

(a)

BrH

Ag

A

(b) + CHCl2 2

Bu O K

B

(c)NH

• •

KOH + CHCl3 C + D (d)

O

Et Et

H

[E]

(e) NaOH (i) CO2

OD

[Intermediate](ii) D F

D

1 4 . Write the mechanism of following reaction :

(a) H

O+

HO CH5 5

dil H

OH

[A]

(b) –O–O–HH

3-Hydroperoxycyclohexene

[B] (c) H–Cl

[A]

Me

Me

CH2 5

O–H

NO2

MeO

(d)

Me

O BF3 [B] (e) OTs KI A + B

1 5 . Find the major product in the reaction the following :

(i)

HO NH2

HNO2

(ii)

HO

P–Ts–OH

H

(iii)

OH

(iv) HMe

HClO4

THF

OAc

1 6 . Decreasing order of E.S.R.

O O

(A)

NHH–N

O

(B)

NHO NH

(C)

O NH ON

H

1 7 . Complete the following equations :

(A) HO3NaOH

OO

+H

O

(B) HO3NaOH

2-equivalent 1-equivalent

+CHO

O

(C) CHONaOH

1 8 . Suggest the mechanism of the following reaction :

(i) CH – CH – CH – CH3 2 3

HSO2 4 C CCH3

H

H

CH3

OH

trans

(ii) CH – C – Br3

CH3

NaOH

alc.CH – C3

CH2

CH3CH3

(iii) CH – CH– CH – CH3 3

C CCH3

H H

CH3

OAC

cis

H

(iv) – CH – CH 2 – CH= CH 2

Br H

NaOHalc.

(v)– CH – CH – CH2 3

Br HNaOHalc. C= C

Ph

H

H

CH3

1 9 .CHOH3CHOH3 XY HC—CHCH2 3

OHCHONa3

; Here X and Y respectively are.

2 0 . COOCH2 5

COOC H2 5

CHONa2 5 Z ; the product Z is.

2 1 .

OHCH3

HC3CH=CHCHCl2 2 200°C P

14

; Here P is.

2 2 .

RR

O

H

[X] ; most likely the compound [X] is.

2 3 .

O

OH OH

O

; the above intermediatory involves.

2 4 . Suggest the product of the reactions :

(A)/H

CH – CH = CH3 2

(B)

HN N C

H CHCl3NaOH

(C) AlCl3

CH3

CH – C– O – C – CH + 3 3

O O

(B) (D) + H – CCl3

O – H

NaOH C

(E) – C – H

O

NaOHD (F)

NCl2

F

(G) OHOH

H

P (H) NaOH

—— C – CH 3

NClOH

O2N

1 . (a) ••O2 2NCHCH <CH < CH CH < 2 3 C HCH < (C H) C6 5 6 5 2

••

••

••

••

(b)

+

+

++ +

O O O O O

< <

+O

(c)

O

CH—C2 —NH2 <

O

CH—C2 —CH—OCH2 3<

O

CH—C2 —CH3 <

O

CH—C2 —H

2 . (i ) 2 < 1 < 3 (ii ) 3 < 1 < 2

3 . Conjugate base of benzene sulphonic acid has greater resonance stabilization than benzoate ion, hence benzene

sulphonic acid is stronger acid than benzoic acid. PhSO3

– has three equivalent resonance structure, so more

stable.but PhCOO– has only two equivalent resonance structure, so less stable.

4 . B is stronger base than A. Here basic strength is controlled by –R effect of —NO2. In B, due to steric inhibition

to resonance of —NO2 by two bulky tertiary butyl group, it is not decreasing basic strenght by —R effect,

hence B is stronger base than Al.

5. (a) Due to resonance in vinyl chloride, C—Cl bond acquire some double bond character while in chloroethane,

C—Cl bond is pure, single sigma covalent bond.

(b) Due to resonance in methyl vinyl ether, bond order of C—C is slightly reduced from two while in ethene

C—C bond order is exactly 2.

(c) Larger size of sulphur compared to oxygen gives greater acidity to CH3SH.

(d) Lone-pair of electron in vinyl amine is involved partly in resonance delocalization and less avaiable for donation

to a lewis acid, hence a weaker Lewis base.

6 . Lone pair of the basic nitorgen is fully avai lable withN

N

HBenzimidazole

::

Basic

Non-basicnitrogen, i.e. not involved in delocalization while lone pair

of non-basic nitrogen is part of aromatic delocalization.

7. (i) CH3NH

2,

(ii) H2N—C—NH2

NH

(iii) PhNH2

8. (i) Hc > H

a > H

b(ii) H

a : Conjugate base is aromatic

9. Acidic strength stabi lity of anion formed after removal of H+ number of e– withdrawing groups.

10. III > II > I

B.D.E. 1

stability of intermediate formed

1 9 . X : HOCH – CHCH2 3

OCH3

and Y : CH – CHCH2 3

OCH3OH

BRAIN STORMING SUBJECTIVE EXERCISE EXERCISE -4 (B)ANSWER KEY

2 0 .

O

COOCH2 5

21.

OHHC3 CH3

CHCH=CH2 2

14

2 2 .

OH

RR

23.

O

OH

1 . In the following benzyl/allyl system

R–CH=CH2 or R [AIEEE 2002]

(R is alkyl group)

decreasing order of inductive effect is-

(1) (CH3)3C– > (CH

3)2CH– > CH

3CH

2–

(2) CH3–CH

2– > (CH

3)2CH– > (CH

3)3C–

(3) (CH3)2CH– > CH

3CH

2– > (CH

3)3CH–

(4) None of these

2 . In the anion HCOO– the two carbon-oxygen bonds are found to be of equal length. What is the reason

for it- [AIEEE 2003]

(1) Electronic orbits of carbon atoms are hybridised

(2) The C=O bond is weaker than the C–O bond

(3) The anion HCOO– has two resonating structure

(4) The anion is obtained by removal of a proton form the acid molecule

3 . The correct order of increasing basic nature for the bases NH3, CH

3NH

2 and (CH

3)2NH is-[AIEEE 2003]

(1) CH3NH

2 < NH

3 < (CH

3)2NH

(2) (CH3)2NH < NH

3 < CH

3NH

2

(3) NH3 < CH

3NH

2 < (CH

3)2NH

(4) CH3NH

2 < (CH

3)2NH < NH

4 . Consider the acidity of the carboxylic acids- [AIEEE 2004]

(i) PhCOOH (ii) o–NO2C

6H

4COOH

(iii) p-NO2C

6H

4COOH (iv) m-NO

2C

6H

4COOH

which of the following order is correct for acidic strength-

(1) i > ii > iii > iv (2) ii > iv > iii > i

(3) ii > iv > i > iii (4) ii > iii > iv > i

5 . Which of the following is the strongest base- [AIEEE 2004]

(1) NH2 (2) NHCH3 (3) NH2

CH3

(4) CHNH2 2

6 . Rate of the reaction R–C + Nu R–C + ZZ Nu

O O is fastest when Z is [AIEEE 2004]

(1) OCOCH3

(2) NH2

(3) OC2H

5(4) Cl

7 . Which one of the following does not have sp2 hybridised carbon [AIEEE 2004]

(1) Acetamide (2) Acetic acid

(3) Acetonitrile (4) Acetone

8 . Due to the presence of an unpaired electron, free radicals are [A IEEE-2005 ]

(1) Chemically inactive (2) Chemically reactive

(3) Cations (4) Anions

EXERCISE–05(A) PREVIOUS YEARS QUESTIONS

9 . The decreasing order of nucleophilicity among the nucleophiles [AIEEE-2005]

(a) CH–C–O3

—

O

(b) CH3O– (c) CN– (d) H

3C

O

S

O

O–is

(1) (d) , (c), (b), (a) (2) (a), (b), (c), (d)

(3) (c), (b), (a), (d) (4) (b), (c), (a), (d)

1 0 . Ter tiary alkyl halides are practically inert to substitution by 2SN mechanism because of [A IEEE-2005 ]

(1) unstability (2) insolubility

(3) steric hinderance (4) inductive effect

1 1 . Among the following acids which has the lowest pka value- [A IEEE-2005 ]

(1) CH3CH

2COOH (2) (CH

3)2CHCOOH

(3) HCOOH (4) CH3COOH

1 2 . Amongest the following the most basic compound is- [AIEEE-2005]

(1) p-nitro aniline (2) Acetanilide

(3) Aniline (4) Benzylamine

1 3 . The increasing order of the rate of HCN addition to compounds A–D is [AIEEE-2006]

(A) HCHO (B) CH3COCH3

(C) PhCOCH3 (D) PhCOPh

(1) D < B < C < A (2) D < C < B < A

(3) C < D < B < A (4) A < B < C < D

1 4 . The increasing order of stability of the following free radicals is [AIEEE-2006]

(1) 6 5 3 6 5 2 3 3 3 2(C H ) C (C H ) C H (CH ) C (CH ) C H

(2) 6 5 2 6 5 3 3 3 3 2(C H ) C H (C H ) C (CH ) C (CH ) C H

(3) 3 2 3 3 6 5 3 6 5 2(CH ) C H (CH ) C (C H ) C (C H ) C H

(4) 3 2 3 3 6 5 2 6 5 3(CH ) C H (CH ) C (C H ) C H (C H ) C

1 5 . CH3Br + Nu– CH3 – Nu + Br–

The decreasing order of the rate of the above reaction with nucleophiles (Nu–) A to D is [A IEEE-2006 ]

[Nu– = (A) PhO–, (B) AcO–, (C) HO–, (D) CH3O–]

(1) D > C > B > A (2) A > B > C > D

(3) B > D > C > A (4) D > C > A > B

1 6 . The correct order of increasing acid strength of the compounds is [AIEEE-2006]

(a) CH3CO2H (b) MeOCH2CO2H

(c) CF3CO2H (d) Me

CO H2 Me

(1) d < a < c < b (2) d < a < b < c

(3) a < d < c < b (4) b < d < a < c

1 7 .

OH

+ CHCl3 + NaOH

O Na — +

CHO

The electrophile involved in the above reaction is [AIEEE-2006]

(1) dichlorocarbene ( :CCl2)

(2) trichloromethyl anion 3(C Cl )

(3) formyl cation (C HO)

(4) dichloromethyl cation 2(C HCl )

1 8 . Which one of the following is the strongest base in aqueous solution ? [AIEEE-2007]

(1) Trimethylamine (2) Aniline

(3) Dimethylamine (4) Methylamine

1 9 . The electrophi le, E at tacks the benzene ring to generate the intermediate –complex. Of thee

following, which –complex is of lowest energy? [A I EEE -20 08 ]

(1)

NO2

+

H E

(2)

H

E+ (3)

NO2

+

H

E(4)

NO2

+ H

E

2 0 . Arrange the carbanions, (CH3)3 C , 3CCl , (CH3)2 CH , C6H5 2CH , in order of their decreasing stability :-

(1) 3 6 5 2 3 2 3 3CCl C H CH (CH ) CH (CH ) C [AIEEE-2009]

(2) 3 3 3 2 6 5 2 3(CH ) C (CH ) CH C H CH CCl

(3) 6 5 2 3 3 3 23C H CH CCl CH C (CH ) CH

(4) 3 3 6 5 2 32 3CH CH CCl C H CH CH C

2 1 . The correct order of increasing basicity of the given conjugate base (R=CH3) is :- [AIEEE-2010]

(1) RCOO < HC C < 2NH < R

(2) RCOO < HC C < R < 2NH

(3) R < HC C < RCOO < 2NH

(4) RCOO < 2NH < HC C < R

2 2 . The strongest acid amongst the following compounds is ? [AIEEE-2011]

(1) CH3CH2CH(Cl)CO2H

(2) ClCH2CH2CH2COOH

(3) CH3COOH

(4) HCOOH

2 3 . Ortho-Nitrophenol is less soluble in water than p– and m– Nitrophenols because :- [AIEEE-2012]

(1) Melting point of o–Nitrophenol is lower than those of m– and p– isomers

(2) o–Nitrophenol is more volatile in steam than those of m– and p– isomers

(3) o–Nitrophenol shows Intramolecular H–bonding

(4) o–Nitrophenol shows Intermolecular H–bonding

2 4 . Which of the following compounds are antiaromatic :- [AIEEE-2012(Online) ]

(I) O....

(II) (III)

(IV) –

(V) +

(VI)

(1) (III) and (VI) (2) (II) and (V)

(3) (I) and (V) (4) (V) and (VI)

2 5 . In the following compounds : [AIEEE-2012(Online) ]

(I) N

H

(II) N

(III) N

H

O(IV)

N

H

the order of basicity is as follows :

(1) IV > III > II > I (2) II > III > I > IV

(3) I > III > II > IV (4) III > I > II > IV

2 6 . Dipole moment is shown by :- [A IEEE -2012 (On l i ne ) ]

(1) trans-2, 3-dichloro- 2-butene (2) 1, 2-dichlorobenzene

(3) 1, 4-dichlorobenzene (4) trans-1, 2-dinitroethene

2 7 . Among the following chloro-compound having the lowest dipole moment is :- [AIEEE-2012(Online) ]

(1) CH2Cl2 (2) CH3Cl (3) C=CH

Cl

H C3

Cl

(4) C=CHCl

H C3 Cl

2 8 . In the below mentioned compounds the decreasing order of reactivity towards electrophilic substitution

is : [A IEEE -2012 (On l i ne ) ]

OCH3 CH3 CF3

(i) (ii) (iii) (iv)

(1) (iii) > (i) > (iv) > (ii) (2) (iv) > (i) > (ii) > (iii)

(3) (ii) > (iii ) > (i) > (iv) (4) (i) > (ii) > (iii) > (iv)

2 9 . Among the following the molecule with the lowest dipole moment is :- [A IEEE -2012 (On l i ne ) ]

(1) CHCl3 (2) CH2Cl2

(3) CCl4 (4) CH3Cl

3 0 . The most basic compound among the following is :- [A IEEE -2012 (On l i ne ) ]

(1) Acetanilide (2) Benzylamine

(3) p-Nitro aniline (4) Aniline

3 1 . Among the following the order of reactivity toward nucleophilic addition is :-[A IEEE -2012 (On l i ne ) ]

(1) HCHO > CH3CHO > CH3COCH3

(2) CH3CHO > HCHO > CH3COCH3

(3) CH3CHO > CH3COCH3 > HCHO

(4) CH3COCH3 > CH3CHO > HCHO

3 2 . The order of stability of the following carbocations:

CH =CH–CH ; CH –CH –CH ;2 2 3 2 2

+

I II

CH2

+

III

+ is :- [ JEE (MA I N ) - 20 13 ]

(1) III > II > I (2) II > III > I (3) I > II > III (4) III > I > II

3 3 . Arrange the following compounds in order of decreasing acidity : [ JEE (MA I N ) - 20 13 ]

(I) (II) (III) (IV)

OH OH

Cl CH3

OH

NO2

OH

OCH3

; ; ;

(1) II > IV > I > III (2) I > II > III > IV

(3) III > I > II > IV (4) IV > III > I > II

PREVIOUS YEAR QUESTIONS ANSWER KEY EXERCISE-05(A)

Q u e. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

A n s 1 3 3 4 4 4 3 2 4 3 3 4 2 4 4

Q u e . 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

A n s 2 1 3 2 1 1 1 3 4 3 2 1 4 3 2

Q u e . 31 32 33

A n s 1 4 3

1 . Which one of the following has the smallest heat of hydrogenation per mole ? [ I IT -93 ]

(A) 1–Butene (B) trans–2–Butene

(C) cis–2–Butene (D) 1, 3–Butadiene

2 . What is the decreasing order of strength of bases OH, NH, HC C, CH–CH2 3 2 [ I IT -93 ]

(A) CH–CH > > OH 3 2 NH HC C > 2 (B) 3 2 2 CH–CH > NH > OH HC C >

(C) 2 3 2OH > NH > HC C > CH–CH (D) 2 3 2NH > HC C > OH > CH–CH

3 . In the following compounds [ I IT -96 ]

OH OH OH OH

I II III IV

CH3

NO2

NO2

The order of acidity is -

(A) III > IV > I > II (B) I > IV > III > II

(C) II > I > III > IV (D) IV > III > I > II

4 . The formation of cyanohydrin from a ketone is an examples of - [ I IT -98 ]

(A) Electrophilic addition (B) Nucleophilic addition

(C) Nucleophilic substitution (D) Electrophilic substitution

5 . The most unlikely representation of resonance structure of p-nitrophenoxide ion is - [ I IT -99 ]

(A)

O–N=O

O

(B)

O–N–O

O

(C)

O=N=O

O

(D)

O–N=O

O

6 . An aromatic molecule will not [ I IT -99 ]

(A) have 4n electrons (B) have (4n + 2) electrons

(C) be planar (D) be cyclic

7 . Amongst the following, the most basic compound is - [ I IT-2000]

(A) C6H5NH2 (B) p–NO2–C6H4NH2

(C) m–NO2–C6H4NH2 (D) C6H5CH2NH2

EXERCISE–05(B) PREVIOUS YEARS QUESTIONS

8 . Which of the following alkenes will react fastest with H2 under catalytic hydrogenation conditions

[ I IT-2001]

(A)

R R

H H

(B)

R H

R H

(C)

R R

R H

(D)

R R

R R

9 . The correct order of basicities of the following compounds is : [ I IT-2001]

CH–C3

NH

NH2

1

,

2

CHCHNH3 2 2

,

3

(CH) NH3 2

,

4

CHCNH3 2

O

(A) 2 > 1 > 3 > 4 (B) 1 > 3 > 2 > 4 (C) 3 > 1 > 2 > 4 (D) 1 > 2 > 3 > 4

1 0 . Which of the following is least stable : [ I IT-2005]

(A) CH–O=CH–CH–HC=CH3 2

(B) CH–O=CH–CH HC CH3 2= –

(C) CH–O–CH–CH–HC=CH3 2

(D) CH–O–CH=CH–HC–CH3 2

1 1 . Among the following, the least stable resonance structure is - [ I IT-2007]

(A)

N O

O

(B) N O

O

(C) N O

O

(D) N O

O

1 2 . The major product of the following reaction is : [ I I T - 2008 ]

BrMe

F

NO2

PhS Na

dimethylformamide

(A)

SPhMe

F

NO2

(B)

SPhMe

F

NO2

(C)

BrMe

SPh

NO2

(D)

Me

SPh

NO2

SPh

1 3 . The correct stability order for the following species is : [ I I T - 2008 ]

O

(I)

(II) O

(III)

(IV)

(A) II > IV > I > III (B) I > II > III > IV (C) II > I > IV > III (D) I > III > II > IV

1 4 . Statement-I : p-Hydroxybenzoic acid has a lower boiling point that o-hydroxybenzoic acid.

B e c au s e

Statement-II : o-Hydroxybenzoic acid has intramolecular hydrogen bonding. [IIT 2003]

(A) Statement-I is True, Statement-II is True ; Statement-II is a correct explanation for Statement-I

(B) Statement-I is True, Statement-II is True ; Statement-II is NOT a correct explanation for Statement-I

(C) Statement-I is True, Statement-II is False.

(D) Statement-I is False, Statement-II is True.

1 5 . Statement-I : Bromobenzene upon reaction with Br2/Fe gives 1, 4-dibromobenzene as the major product.

B e c au s e

Statement-II : In bromobenzene, the inductive effect of the bromo group is more dominant than the mesomeric

effect in directing the incoming electrophile. [I IT 2008]

(A) Statement-I is True, Statement-II is True ; Statement-II is a correct explanation for Statement-I

(B) Statement-I is True, Statement-II is True ; Statement-II is NOT a correct explanation for Statement-I

(C) Statement-I is True, Statement-II is False.

(D) Statement-I is False, Statement-II is True.

1 6 . Out of anhydrous AlCl3 and hydrous AlCl3 which is more suluble in diethyl ether ? Explain with reason.

[I IT 2003]

1 7 . Match Ka values with suitable acid : [I IT 2003]

Ka Acid

(A) 3.3 × 105 (p) —COOH

(B) 4.2 × 10–5 (q) —COOH Me—

(C) 6.3 × 10–5 (r) —COOH Cl—

(D) 6.4 × 10–5 (s) —COOH MeO—

(E) 30.6 × 10–5 (t) —COOH ON—2

1 8 . Give resonating structures of following compound. [I IT 2003]

OH

1 9 . Which of the following is more acidic and why ? [I IT 2004]

NH3

F(II)

NH3

(I)

2 0 . The compound that does NOT liberate CO2, on treatment with aqueous sodium bicarbonate

solution, is - [JEE ADVANCED 2013]

(A) Benzoic acid (B) Benzenesulphonic acid

(C) Salicylic acid (D) Carbolic acid (phenol)

2 1 . The hyperconjugative stbilities of tert-butyl cation and 2-butene, respectively, are due to

(A) p (empty) and * electron delocalisations [JEE ADVANCED 2013]

(B) * and electron delocalisations

(C) p (filled) and electron delocalisations

(D) p (filled)* and * electron delocalisations

2 2 . The total number of lone-pairs of electrons in melamine is [JEE ADVANCED 2013]

1. (D) 2. (A) 3. (D) 4. (B) 5. (C) 6. (A) 7. (D) 8. (A)

9. (B) 10. (D) 11. (A) 12. (A) 13. (D) 14. (D) 15. (C)

16. Anhydrous AlCl3 is more soluble.

17. A-(s) ; B-(q) ; C-(p) ; D-(r) ; E-(t) ;

19. II is more acidic. 20. (D) 21. (A) 22. (6)

ANSWER KEYPREVIOUS YEARS QUESTIONS EXERCISE -5 (B)