classnote-50ea6e07292e7

ORGANIC chemistry

.J .S

IR

IIT-JEE ChEmistry by N.J. sir

CONCEPTUAL

N

IMPROVEMENT OF G.O.C.

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1


ORGANIC chemistry

DPP NO- 1 1.

Time: 15 minutes

Draw Resonance hybrid of the following compounds:-

(1)

OH

(2)

O (3)

(4)

O

O

–

O

(6)

O

IR

(5)

O

H2C = C – NH – CH3

(8)

.J .S

(7)

–

:

CH=CH—NH2

(9)

(10)

O –O

H

H2N

O

O

O

(11)

(12)

(13)

(15)

O

 Me — S — CH2

–

O

N

– O

H—C

+ CH2 (14)

O (16)

CH3 — N O

O

(17)

(18)

.. H2N — C  N :

–


2

(19) (21)

 NO3

Me O

N

(20)

O=C=O

(22)

H2N — C — NH 2 :

NH

O

(23)

(24) +

(25)

+

O (26)

–

O

–

(27)

(28)

IR

O

OH

–

(29)

.J .S

:O:

(30)

– O – CH2

(31)

– O—C=O – O

NH2

(32)

N

NO2


3


ORGANIC chemistry

DPP NO- 2 1.

Time: 15 minutes

Compare relative stability of following resonating strutures

S.No. Resonanting structures (1)

H2C = CH — Cl

Order of stability

Reason

  H2C — CH = Cl

(a)

(b)

O–

O –

(2)

(3)

(4)

(b)

 CH2 — CH = NH

 H2C = CH — NH

(a)

(b)

 CH3 — O — CH2

 CH3 — O = CH2

(a)

(b)

H—N=C=O :

(a) N

: :

O

O+

(c)

Me + N – O O

O

(a) H

(b)

:

Me

(6)

  H — N— C  O

  H— N C— O

.J .S

(5)

IR

(a)

(b)

OH

(7)

+

(a)

+

N

(8)

(b)

(a)

+ (b)

– O

(c)

O–

O

(9)

+

O (a)

(b)

S–

S (10)

H

H

– (a)

(b)


4

S.No. Resonanting structures .. H — .O. — C  N:

– + H — O = C = N: :

(11)

Order of stability Reason

(a)

(b)

O–

O

O –

(12)

C

N (b) O– +

O (13)

C

C

N (a)

N (b)

(14)

– CH2

H

H

C N– (c)

O–

+

C

– CH2

(b)

(c)

:

: :

O

O

+

(15) (a)

+

(b)

– N

N

(16)

–

(a) O

(b) O–

O

N

–

(a)

+ N

:

+ (a)

(b)

O–

O

(19)

O

(b)

N:

(18)

CH2

H

.J .S

(a)

(17)

+

O–

O

N– (c) O

IR

N (a)

O –

–

(a)

(b)

(c)


5

IIT-JEE ChEmistry by N.J. Sir

ORGANIC chemistry

DPP NO- 3 1.

Time: 15 minutes

Compare relative stability of following resonating strutures

S.No.

Resonanting structures

Order of

Reason

stability

+ CH2

O

(a) :

+ H2N — CH = NH 2

(2)

+ CH2 (b)  .. H2N  CH — NH2

(a)

O

+

(3) (a)

(b) O–

.J .S

O

Me — N +

O

–

:

(a) – + H—C = N = N—H (a)

H3C — HC = C = O (a)

– H—C—N—H

O–

– CH3—C—CH2

CH3—C = CH2

N

:

O

H—C = N—H (b) O–

(a)

(8)

  Me — CH — C  O (b)

O (7)

+ H—C—N—N—H – (b)

:

(6)

O (b)

:

Me — N +

(5)

(a)

+ CH2 — C = C — CH3

(9)

(b)

+ CH2 = C — C —CH3 H H (b) O–

H H (a)

O (10)

–

C O

(c)

(b) +O

O

O

(4)

– CH2

O

IR

(1)

– O

O (a)

–

C O

– O

(b)


6

S.No.

(11)

Resonanting structures

H

Order of stability

H (a)

(12)

Reason

–

N

O

(b) – O

N

(a)

– N

(b)

O

–

(c)

O–

O

(13) –

(b)

O–

O

(14)

Cl – (b)  Me — CH — C  CH (b)

.J .S

Cl (a)

(15)

 Me — CH = C = CH (a)

(16)

 .. Me — .O. — CH = CH — CH2

(a)

: :

(17)

S

–

(b)

  O—CO (b)

N H2N — C = N: (a) O

Me

: :

(20)

O=C=O (a) :

(19)

 Me — O . . = CH — CH = CH2

S – (b)

(a) (18)

IR

(a)

OH

(a)

– + O=C—O (c) – + H2N = C = N: (b) O–

Me (b)

+ O–H


7


ORGANIC chemistry

DPP NO-4 1.

Time: 15 minutes

Identify no. of -hydrogen in the following compounds No of -hydrogen

No. of -hydrogen

CH3 (2)

(3)

(4)

IR

(1)

(5)

.J .S

CH3

(6)

CH3

H 3C

CH3

(7)

(8)

CH3

CH3

N

CH3

(9)

CH3 (10)

CH3

CH3

CH3

(11)

(12)

CH3


8

No of -hydrogen

No. of -hydrogen

CH3 (13)

(14)

H2C

(16)

H 3C

CH3

CH3

(15)

CH3

H3C

CH3 H 3C

H3C

CH3

(18)

H 3C

CH3

IR

(17)

CH3

CH3 CH3

(20)

H 3C

N

H 3C

CH3

H3C

.J .S

(19)

H3C


9


ORGANIC chemistry

DPP NO- 5 1.

Time: 15 minutes

Identify no. of -hydrogen in the following compounds No of -hydrogen

H2C

No. of -hydrogen

CH3

(1)

(2)

CH3 CH3

(4)

H3C

H3C

(5)

(6)

CH3 CH3

(7)

CH3

.J .S

H 3C

IR

(3)

(8)

H 3C

CH3 (9)

(10)

H3 C

(11)

N

H2C

H 3C

(12)

CH3 (13)

(14)


10

No of -hydrogen

No. of -hydrogen

H 3C

H2C

(15)

(16)

CH3

CH3

(17)

(18)

CH3 CH3

CH3

(20)

H3C H 3C H3C

CH3 CH3 CH3

(20)

H 3C H 3C H3C

N

.J .S

CH3

CH3

IR

(19)

CH3


11


ORGANIC chemistry

DPP NO- 6 Q.1

Time: 15 minutes

Given the relative Stability of the following compound

1. H (i)

ii)

(iii)

(iv)

Me 2.

Me

Me

Ph — CH2 — CH = CH — C — Me

(v)

Me — CH — CH = CH — C — Me

Me

Me

(i)

(ii)

Me

PH — CH = CH — C — Me

Me

IR

Me

Me — C — HC = CH — C — Me

Me

Me

(iii)

Me

(iv)

Me

Me (i)

+ CH3

+ Me — CH2

.J .S

3.

+ Me — CH — CH — CH3

(ii)

Me — C — CH2 + Me (iv)

(iii)

+

+ 4. (i)

+

7.

+

(iii)

(iv)

+

N

5.

6.

(ii)

+

+

+

(i)

(ii)

(iii)

(iv)

(i)

(ii)

(iii)

(iv)

H2C = C = CH2 (i)

Me — CH = CH2 (ii)

(iii)

(iv)


12


ORGANIC chemistry

DPP NO- 7 Q.1

Time: 15 minutes


1. (i)

(ii)

(iii)

(iv)

(i)

(ii)

(iii)

(iv)

(v)

(vi)

(vii)

2.

+ CH2

+ CH2

+ CH2

CH3 (i)

CD3 (ii)

CT3 (iii)

(iv)

+ CH2

+ CH2

+ CH2

IR

+ CH2

+ CH

4.

(i)

5.

Me

(ii)

+ CH2

N

+ CH2

.J .S

3.

(i)

(ii)

– CH2

– CH2

CF3 (i)

CCl3 (ii)

(iii)

+ CH2

(iii) – CH2

(iv)

+ CH2

(iv) – CH2

6.

Me (iii)

(iv)


13


ORGANIC chemistry

DPP NO- 8 Q.1

Time: 15 minutes


1.

(i)

(ii)

(iii)

+

+ 2.

+ (ii)

+ CH2

3.

(Et)2 CH



(iv)

(Et)3 C

(ii)



+ CH2—CH2

(iii)

(iv)

.J .S

(i)

(iii)

IR

+ (i)

+

4.

CH (i)

+

+



(ii)

5. (i)

(ii)

N

6.

(iii)

(iii)

(iv)

(iv)

(i)

(ii)

(iii)

(i)

(ii)

(iii)

(iv)

7.


14


ORGANIC chemistry

DPP NO- 9 Q.1

Time: 15 minutes


1. (i)

(ii)

(iii)

2. (i)

(ii)

(iii)

IR

3. (i)

(ii)

.J .S

(iii)

4. (i)

(ii)

5.

6.

(ii)

N

(i)

CH3 — C  C — CH3 (i)

C

(iii)

C

H3C — CH2 — C  CH (ii)



C

C

7. (i)

(ii)

CH3

(iii)

C

C

(iii)

H3C — C  C — CH3 (iv)

H 3C

8. (i)

(ii)


15


ORGANIC chemistry

DPP NO- 10 Q.1

Time: 15 minutes

Given the relative Stability of the following compound H 2C

1.

2.

(ii)

CH3

(i)

CH3

3.

4.

(ii)

IR

(i)

CH3

CH3

(ii)

(i)

(ii)

.J .S

(i)

CH2

CH3

5.

(iii)

CH3

CH3

6.

(i)

(ii)

(ii)

(i)

(ii)

8.

N

7.

(i)

(i) H3O

O

(ii) H3O

O CH2

9.

CH3

10. (i)

Q.2

(ii)

(i)

(ii)

Hyperconjugation involves (A) Delocalization of s-electrons into an adjacent p-bond. (B) Delocalization of n-electrons into an adjacent double bond. (C) Delocalization of -electrons into an adjacent double bond. (D) All are true 


16


ORGANIC chemistry

DPP NO- 11

Q.2 Q.3

Q.4

Hyperconjugation is possible in (A) alkenes (B) alkynes

(C) carbocations

(D) all of these

Hyperconjugation is possible in (A) Free radicals (B) Carbanions

(C) Alcohols

(D) Amines

Hyperconjugation occurs in (A) CH3 — CH = CH2 CH3 (C) CH = CH2 CH3

(B) CH3 — CH2 — CH = CH2 (D) all ot these

Hyperconjugation occurs in CH 3 (A) CH3 — C — CH = CH2

(B) CH3 — CH = CH — CH3

CH3 (C) Ph — CH = CH2 Hyperconjugation occurs in CH3 CH3 CH3 (A)

(B)

CH3

Q.6

(D)



CH3

.J .S

Q.5

IR

Q.1

Time: 15 minutes

(C)

CH3 C (D)

CH3 CH3

Br

CH3

Hyperconjugation occurs in + CH2 (A)

+

(B)

+ CH

Q.7

N

(C)

(D) all of these

Hyperconjugation occurs in  (A) CH3

 (B) CH3  CH2

CH3

(C)

CH3

(D) both (B) and (C)

CH3

CH3 Q.8

CH3 How many hyperconjugable H-atoms does this cation has? (A) 10 (B) 6 (C) 12

(D) 15


17

CH3

Q.9

CH3 CH3 CH3 How many hyperconjugable H-atoms does this cation has? (A) 5 (B) 6 (C) 12

(D) 8

HB Q.10

HA — C — CH = CH 2 HC Canonical structures due to hyperconjugation in this molecules can be written as HB HA HA – – – (A) C = CH — CH2 C = CH — CH2 C = CH — CH2 HC+ HC HA+ HC HB+ HB

HC

+ C = CH — CH2 HA–

HA HC

+ C = CH — CH2 H– B

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

Q.11

CH3

CH3

+ C = CH — CH2 HC–

HB

.J .S

CH3

HA

IR

HB (B)

CH3 CH3 CH3 I II III Among these compounds, which of the following orders is correct for their nobond-resonance energy? (A) III > II > I (B) I > II > III (C) I > III > II (D) II > III > I Q.12

Compound

Homolytic bond dissociation energy

N

  104 Kcal/mol CH4  CH3  H CH3 CH3  CH3 — CH CH 3 — C H 92 Kcal/mol CH3 CH3 Notice the hemolytic bond-dissociation energy of the alkanes. Now, ignoring the contribution of inductive effect, no-bond-resonance energy of tert-butyl radical can be calculated to be (A) 6 Kcal/mol (B) 10 Kcal/mol (C) 12 Kcal/mol (D) 14 Kcal/mol

Q.13 I II III Among these cycloalkenes, which of the following orders of stability is correct? (A) I > II > III (B) III > II > I (C) II > I > III (D) II > III > I


18

Q.14 I II III Among these dienes, which of the following orders of stability is correct? (A) I > II > III (B) III > II > I (C) II > III > I (D) II > I > III

CH3 Q.15

CH3

IR

I II III IV Which of the following statements is correct, about these cycloalkenes? (A) Stability difference between I and II is more than that between III and IV (B) Stability difference between I and II is less than that between III and IV (C) Overall, stability order is I > II > III > IV (D) None of these

CH3 Q.16

C = CH2

I

CH3 II

CH3

CH3 C=C

H

CH3 III

.J .S

H

H

C=C

H CH3 Which of the following orders is correct for heat of combustion of these isomeric alkenes? (A) I > II > III (B) III > II > I (C) III > I > II (D) II > III > I

Q.17

CH2 = CH — C  C — CH = CH2

Q.18

N

I II Which of the following orders is correct for heat of combustion of these isomers? (A) I > II (B) II > I (C) I = II (D) Not predictable

I II III Which of the following order is correct for heat of combustion of these isomers? (A) I > II > III (B) III > II > I (C) II > III > I (D) I > III > II

CH2 — CH2 — CH3

CH3

CH3

Q.19

CH3 CH2CH3 CH3 I II III Which of the following orders is correct for heat of hydrogenation of these compounds? (A) I > II > III (B) III > II > I (C) II > I > III (D) I > III > II


19

Q.20 I II III Which of the following orders is correct for heat of hydrogenation of these compounds? (A) I > II > III (B) III > II > I (C) III > I > II (D) II > III > I

Q.21 I II III Which of the following orders is correct for heat of hydrogenation of these compounds? (A) I > II > III (B) III > II > I (C) II > I > III (D) I > III > II

IR

Q.22

I II III Which of the following orders is correct for heat of hydrogenation of these compounds? (A) I > II > III (B) III > II > I (C) II > I > III (D) III > I > II

.J .S

CH3

Q.23

CH3

CH2

I II III Which of the following orders is correct for heat of hydrogenation of these compounds? (A) I > II > III (B) III > II > I (C) III > I > II (D) II > I > III

CH3 Q.24

CH2

CH3

CH3 CH3 CH3 I II III Which of the following order is correct for heat of hydrogenation of these compounds? (A) I > II > III (B) III > II > I (C) II > III > I (D) III > I > II

Q.25

N

CH3

a

b

CH3 a and b are the length of these two C = C bonds. Now, which of the following orders is correct? (A) a = b (B) a < b (C) b > a (D) Not predictable CH3

Q.26

a

b

c

CH3 a, b and c are the length of these C = C bonds. Now, which of the following orders is correct? (A) a = b = c (B) a > b > c (C) c > b > a (D) b > c > a


20

Q.27

Inductive effect of – NO2 group operates in NO2 NO2 (A)

Q.28

(B)

NO2 (C)

Inductive effect of – CH3 group operates in CH3 CH3 (A)

(B)

(D) all of these

CH3 (C)

(D) both (B) and (C)

O –  —C—O — CH3 —O I II III Which of these groups has + I effect? (A) I (B) II (C) III

– Q.30

(D) unhybridized

N

.J .S

Hybridization of the negatively charged C-atom of this anion is (A) sp3 (B) sp2 (C) sp



(D) all of these

IR

Q.29


21


ORGANIC chemistry

DPP NO- 12

Time: 15 minutes +

Q.1 Empty orbital of this carbocation is (A) 2p (B) sp3 Q.2

(C) sp2

(D) sp

Negative charge of which the following carbanions is not resonance – stabilized?

–

–

(A)

(B)

(C)

(D)

– OCH3

OCH3 +

Q.3

+

OCH3

+

IR

OCH3

–

OCH3

Q.4

.J .S

OCH3 I II III Which of the following orders is correct for the stability of these carbocations? (A) I > II > III (B) III > II > I (C) I > III > II (D) II > III > I +

I

O

+

II

N CH3

Q.5

N

+ O II Which of the following orders is correct for the stability of these carbocations? (A) I > II > III (B) III > II > I (C) II > I > III (D) II > III > I +

+

+

I II III Which of the following orders is correct for the stability of these carbocations? (A) I > II > III (B) III > II > I (C) II > I > III (D) II > III > I

+ Q.6

+

+

I II III Which of the following orders is correct for the stability of these carbocations? (A) I > II > III (B) III > II > I (C) I > III > II (D) II > I > III


22

Q.7

I

+ C

II

+ CH2

+ CH2 III

+

IR

Which of the following orders is correct for the stability of these carbocations? (A) I > II > III (B) III > II > I (C) II > I > III (D) III > I > II

+

+

Q.8

Q.9

.J .S

I II III Which of the following orders is correct for the stability of these carbocations? (A) I > II > III (B) III > II > I (C) II > I > III (D) II > III > I Which of the following reactions is not possible? + – ClO4 HClO4 (A) + H2O OH  +

(B)

HClO4 OH 

– ClO4

+ H2O


Which of the following reactions is not possible?

N

Q.10

(A)

(B)

AgClO4  Cl  HO

OH

AgClO4  Cl  H2O

OH

2



23

Q.11

– CH3 — CH — CH 3

– CH3 — CH2

– CH3 — C — CH 3

CH3 I II III Which of the following orders is correct for the stability of these carbanions? (A) I > II > III (B) III > II > I (C) II > I > III (D) I > II > III

Q.12

– CH2

– CH2 = CH — CH 2

– CH3 — CH2

I II III Which of the following orders is correct for the stability of these carbanions? (A) I > II > III (B) III > II > I (C) II > III > I (D) II > I > III –

–

IR

– Q.13

–

Cl

Q.14

.J .S

CH3 Cl I II III Which of the following orders is correct for the stability of these carbanions? (A) I > II > III (B) III > II > I (C) III > I > II (D) II > III > II

–

–

Cl

Cl I II III Which of the following orders is correct for the stability of these carbanions? (A) I > II > III (B) III > II > I (C) II > I > III (D) II > I > III

NO2

N

Q.15

–

–

–

NO2

NO2 I II III Which of the following orders is correct for the stability of these carbanions? (A) I > II > III (B) III > II > I (C) II > I > III (D) II > III > I

Q.16

–

 CH2 = CH — CH2

– I II III Which of the following orders is correct for the stability of these carbanions? (A) I > II > III (B) III > II > I (C) I > III > II (D) II > III > I


24

Q.17

 CH2 — CH = CH2  II CH2 — CH = O  III CH2 — CH2 — CH3 Which of the following orders is correct for the stability of these carbanions? (A) I > II > III (B) III > II > I (C) II > I > III (D) II > III > I

I

– Q.18

–

O

O

–

–

O

O

O

Q.19

IR

O O O I II III Which of the following orders is correct for the stability of these carbanions? (A) I > II > III (B) III > II > I (C) II > III > I (D) II > I > III –

O

O – I II III Which of these carbanions is sp3 hybridized? (A) I (B) II (C) III

Q.20

.J .S

O

 CH2 = CH — CH2

 CH3 — CH2

(D) nonw of these

CH3

CH3 — C

CH3 I II III Which of the following orders is correct for the stability of these radicals? (A) I > II > III (B) III > II > I (C) I > III > II (D) III > I > II CH2

N

Q.21

CH2

CH2

CH3

CH3

CH3 I II III Which of the following orders is correct for the stability of these radicals? (A) I > II > III (B) III > II > I (C) II > I > III (D) II > III > I

CH3 Q.22

CH3 — H

CH3CH 2 — H

CH3 — H H

I II III Which of the following orders is correct for the energy required for homolytic cleavage of indicated C – H bonds? (A) I > II > III (B) III > II > I (C) III > I > II (D) II > III > I


25

Q.23

I

II

III

CH2 — H

CH2 — H

CH2 — H Which of the following orders is correct for energy required for homolytic cleavage of indicated C – H bonds? (A) I > II > III (B) III > II > I (C) II > I > III (D) III > I > II Q.24

I

Cl — CH2 — COOH

II

Br — CH2 — COOH

III

I — CH2 — COOH

I

Cl — CH2 — COOH

II

O2N — CH2 — COOH

III

CH3 — COOH

.J .S

Q.25

IR

Which of the following order is correct for the acidic strength of these carboxylic acids? (A) I > II > III (B) III > II > I (C) II > I > III (D) II > III > I

Which of the following order is correct for the acidic strength of these carboxylic acids? (A) I > II > III (B) III > II > I (C) II > I > III (D) II > III > I Q.26

COOH

COOH

HCOOH COOH COOH I II III Which of the following order is correct for the acidic strength of these carboxylic acids? (A) I > II > III (B) III > II > I (C) II > I > III (D) II > III > I

H2C

CH3

CH3 — Si —— CH2 — COOH

N

Q.27

CH3

In this molecule, the effect of trimethylsilyl group (encircled) on the acidity of – COOH group is of (A) strong electron donating nature (B) strong electron withdrawing nature (C) weak electron withdrawing nature (D) both (A) and (C) OH

OH

OH

Q.28 O

O

O

O

O I II III Which of the following order is correct for the acidic strength of these compounds? (A) I > II > III (B) III > II > I (C) II > I > III (D) III > I > II


26

2 OH

1 OH

Q.29

OH 3

O

O

4 OH Which of these – OH groups is most acidic? (A) 1 (B) 2 (C) 3

(D) 4

H 3 H 2

Q.30 O

N



.J .S

IR

O H1 Which of the following orders is correct for the acidity of these indicated H-atoms? (A) 1 > 2 > 3 (B) 3 > 2 > 1 (C) 2 > 1 > 3 (D) 1 > 3 > 2


27


ORGANIC chemistry

DPP NO- 13 1.

Time: 15 minutes

Identify the Nature of compound

S.No. Compound

Aromatic

Anti-aromatic

Non-aromatic

(1) –

(2) +

(3)

IR

+ (4)

+ – (5)

–

.J .S

(6) (7)

O (8) –

(9)

(10)

(11)

N

+

B H

(12)

(13)

O

+

O

O

O B H


28


ORGANIC chemistry

DPP NO- 14

Time: 15 minutes

S.No. Compound

Aromatic

Anti-aromatic

Non-aromatic

(1)

(2) O

(3)

IR

S

(4) N H

O + (6)

O (7)

O – (8)

N

O +

.J .S

(5)

(9)

(10)

(11)

O O


29


ORGANIC chemistry

DPP NO- 15

Time: 15 minutes

S.No. Compound

Aromatic

Anti-aromatic

Non-aromatic

O

(1) O

(2)

O

IR

N H O

N H

N (4)

N

N (5)

N

(6)

(7)

N

N H

.J .S

(3)

+ N H

(8)

(9)

N

+ M—N

N—H

N—H


30


ORGANIC chemistry

DPP NO- 16 1.

Time: 15 minutes

Identify the Nature of compound

S.No. Compound

Aromatic

Anti-aromatic

Non-aromatic

– (1)

IR

(2)

.J .S

(3)

CH3 B

(4)

(5)

+ N

(6)

(7)

N

N H

:S:

N

(8)

N O

N (9)

N

N H

N N


31


ORGANIC chemistry

DPP NO- 17

Time: 15 minutes

S.No. Compound

Aromatic

Anti-aromatic

Non-aromatic

IR

(1)

(2)

(4) –

(5)

.J .S

(3)

+ CH2

N

(6)

– CH2

(7)

(8) N O

(9)


32


ORGANIC chemistry

DPP NO- 18

Time: 15 minutes

S.No. Compound O

Aromatic

Anti-aromatic

Non-aromatic

(1)

(2)

IR

O (3)

N

H

CH2

(6)

(7)

(8)

–

N

(5)

.J .S

(4)

(9)


33


ORGANIC chemistry

DPP NO- 19

Time: 15 minutes

S.No. Compound

Aromatic

Anti-aromatic

Non-aromatic

(1)

(2)

H—N H—B

IR

H B N—H N H

B—H

Borazole

(3) (4)

* (2)

.J .S

I

(C* = C14)

KH  

(A) + gas (Identify A, B, C, D) + H

B+C+D

Determine the number of  electrons for each compound below, then indicate whether they are aromatic, antiaromatic, or neither. Assume the molecules are neutral and planar unless otherwise indicated. NH2 Et O N N S N B N H H

N

(3)

Number of  electrons:_____ Aromatic, Antiaromatic, or Neither ?





34


ORGANIC chemistry

DPP NO- 20

Time: 15 minutes

1. Compare Acidic Strength S.No. Compound

COOH

Compare Ka value a

b

Compare pKa value a

b

COOH CH3

(1) (b) COOH

CH3 (2) (b)

(3)

.J .S

(a)

(a)

(a)

CH2

(b)

N

O

(5)

(b)

CH

(4)

IR

(a) COOH

O

O

O

(a) O

(b) O

O OMe

(6) O

(a)

O

(b)


35

S.No. Compound

Compare Ka value b

a

b

:

a

Compare pKa value

NH2

OH (7)

(b)

:

(a)

NH2

:OH (8)

(b)

OH

OCH3

CN

(a) (10)

(b)

Cl—CH2—CH2—COOH (a)

(11)

OH (a)

(12)

Cl (b)

OH

HF

NH3

HC  CH (a) CH4

N

(14)

(a)

(15)

CH3— CH—COOH

(b)

(a) (13)

.J .S

(9)

IR

(a) OH

(b) .. NH3 (b)

NH3

HC  N

(b) .. NH3

(a)

(b)

OH

OH (16)

O (a)

O (b)


36


ORGANIC chemistry

DPP NO-21

Time: 15 minutes

1. Compare Acidic Strength S.No. Compound

O

Compare Ka value a

b

Compare pKa value a

b

OH

O Ph — S — OH

(1)

(2)

R — OH (a) O OH

IR

O (b) O

(a)

R — C — OH (b) O OH

Me

(a) O OH

(4)

Me (a)

.J .S

(3)

Me (b)

OH

(b)

OH

F

N

(5)

OH

F (b)

(a)

(6) (7) (8) (9)

OH

+ R 3N

OH N

(a) CH4 (a) HF (a) H2S (a)

C (b) HF (b) HI (b) H2O (b)


37

S.No. Compound

Compare Ka value a

Compare pKa value b

a

b

(10) (a)

N

N

O2N

(a) (12)

N

(b)

O2N

N

N (a) O

N (b)

O OEt

H

OEt

H

IR

(11)

(b)

(13)

O

O (a)

(b)

N (a)

(15)

F

.J .S

(14)

(b)

CCl3OH

CF3OH

(a)

(b)

(16)

(a)

(b)

OH

OH

(17)

Cl (a)

(18)

N

O

Br (b)

O

OH

(a)

OH (b)

O

(19)

O

OH

OH

(a) (20)

(b)

CHCl3

HCF3

(a)

(b)


38


ORGANIC chemistry

DPP NO- 22

+O H Q.2

+ N

:

Rank the following in order of decreasing acidity.

:

Q.1

Time: 15 minutes

N

H

HO

CH3

H

CH3

Consider the following compound. Rank the labeled proton in increasing order of acidity x

COOH

O OH c

HO

(b)

F

a

F COOH y

SH

COOH

b

Q.3

Write the stepwise ionization of acid z

IR

(a)

Write correct order of acidic strength as a to d. (a) H O H N N

(b)

(c)

H

.J .S

H

H

H

O

(d)

OH I

Q.4

Among

OH

Me

&

which is more acidic & why? Explain through canonical

I

Me

NO2

forms.

NO2

Questions No. 5 to 7 (3 questions)

N

O

(b) HOH2C H (c) CH3

O OH (a)

H (d) CH3

Cortisone O

Q.5

Q.6

Q.7

H Cortisone contains which functional groups? (A) Ether, alkene, alcohol (B) Alcohol, ketone, amine (C) Alcohol, ketone, alkene (D) Ether, amine, ketone

Total stereoisomer of the compound Cortisone is (A) 32 (B) 64 (C) 66

(D) 128

Total number of chiral center in Cortisone: (A) 4 (B) 5 (C) 6

(D) 7


39

Q.8

Which order of acid strength is wrong COOH COOH

NO2

COOH

CH3 (A)

>

(B)

SO3H

COOH

COOH

(C)

Cl

COOH >

(D)

OCH3

>

COOH

IR

Q.10

COOH

Which is the order of acidity of the following compounds? EtCO2H CH3CO2H CH3SO3H a b c (A) b > a > d > c (B) d > c > a > b (C) d > c > b > a

CF3SO3H d (D) d > a > b > c

Which of the following carbon will be deprotonatated first on treatment with base. 4 2 1 3 5

.J .S

Q.9

>

O

N

(B) 5

(C) 2

(D) 3

N

(A) 4


40


ORGANIC chemistry

DPP NO-23 1.

Time: 15 minutes

Compare which is more basic in nature

S.No. Compounds

Compare Kb value a

NH2

b

Compare pKb value a

b

NH2 CH3

(1) (a) NH2

(b)

CH3 (2) (a)

(b)

N H (b)

N

(a) (4)

N H (b)

O (a)

N—H

(5)

(7)

N

O (a)

(6)

.J .S

(3)

IR

NH2

N:

(b)

H N

H N

(a)

(b)

N (a)

N N (b)


41


ORGANIC chemistry

DPP NO- 24

Time: 15 minutes

1. Compare which is more basic in nature S.No. Compounds

(1)

Compare Kb value a

b

Compare pKb value a

b

N

N

N

(a)

(b) H N

N (a)

IR

(2)

:

:

(b) NH2

NH2

.J .S

(3)

CH3

(a)

(b) NH2

CH3

(4)

Ph — NH — Me

(5)

(a) Ph — NH — Me

(b) Ph — N — Me

Me

(a)

(b)

(6)

(7)

N

NH2

Me

NH2

(a) H2N — C

= NH

(b) H2N — C = NH

NH2

CH3 (b)

(a) NH2

NH2 Me

Me

(8) (a)

(b)


42

S.No. Compounds

Compare Kb value a

b

Compare pKb value a

b

N

(9)

N (b) O

(a) (10)

N H (b)

N (a) S

N H (a) –

IR

(11)

N H (b) –

(a) – O

(b)

– CH2

(13) (a)

(b)

NH

HN

.J .S

(12)

N

(14)

(a)

HN

NH2

NH2

HN

NH2 (b) NH2 HN

(15) NO2 (a)

Cl (b)


43


ORGANIC chemistry

DPP NO- 25 Q.1

Time: 15 minutes

Which Nitrogen is most basic a NH2

b N

Me

(i)

(ii) N b

N a

b NH2

O

(iv)

C

: :

a H 2N

a N O

N: b

IR

(iii)

N c H

a N—H

NH a

(vi)

CH3 — C

.J .S

(v)

c H—N

N—H b

NH2 b

a NH2

O

(vii)

2.

(viii)

NH2 — C — CH 2 — CH 2 — NH b a

N b H

Which is more basic & why?

O

H

OMe

N

C

CH3

NH

C

C

NH

H2N (i)

NH

H2N (ii)


44

classnote-50ea6e07292e7

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