dr. sangeeta khanna ph.d 1 · a. position isomerism b. metamerism c. functional isomerism d. all...

Dr. Sangeeta Khanna Ph.D 1 CHEMISTRY COACHING CIRCLE D:\Important Data\2016\+1\Org\Test\GT-5\Grand Test -V (organic Chemistry) Level - 1.docx

Dr. Sangeeta Khanna Ph.D


LEVEL – 1 (21.12.2016)

TOPIC: IUPAC NAMING, GENERAL ORGANIC CHEMISTRY & ISOMERISM

READ INSTRUCTIONS CAREFULLY

1. The test is of 1 hour duration.

2. The maximum marks are 160.

3. This test consists of 40 questions.

SECTION – A (Single Answer Type) Negative Marking [-1]

This Section contains 40 multiple choice questions. Each question has four choices A), B), C) and D) out of which ONLY ONE is correct. (Mark only One choice) 40 × 4 = 160 Marks

1. The IUPAC name of is

a. 3-vinyl-3-ethyl-2-propene b. 3-Ethyl-3-vinylprop-2-ene c. 3-Ethylpenta-1, 3-diene d. none C

2. The IUPAC name of the compound is :

a. Toluene carbonyl chloride b. 3-Methyl benzene carbonyl chloride c. 5-Methyl benzoyl chloride d. 5-Methyl benzene carbonyl chloride B

3. An electrophilic reagent must have

a. a vacant orbital b. an orbital containing one electron c. an orbital containing two electrons d. a positive charge on it A

4. The hybridization states of the carbon atom (1) and carbon atom (2) in the compound

2

321

HCHCCN are respectively

a. sp2 and sp b. sp3 and sp c. sp and sp2 d. sp and sp C

5. The IUPAC name of the compound

a. 3, 3-Diethyl-4-methyl-5-isopropyl octane b. 3, 3-Diethyl-5-isopropyl-4-methyl octane c. 4-Isopropyl-5-methyl-6,6-diethyl octane d. 6,6-Diethyl-4-isopropyl-5-methyl octane B

CH3CH2CH2CH – CH

CH

CH3

C – CH2CH3

CH2CH3

CH2CH3 CH3 CH3

COCl

CH3

C = CH – CH3

H5C2

CH

CH2



6. Among the following carbon radicals, the stability decreases in the order

a. (CH3)3C > CH2 = CH – CH2 > (CH3)2CH > CH3CH2

b. (CH3)3C > (CH3)2CH > CH2 = CH – CH2 > CH3CH2

c. CH2 = CH – CH2 > (CH3)3C > (CH3)2CH > CH3CH2

d. (CH3)3C > (CH3)2CH > CH3CH2 > CH2 = CH – CH2 C

7. Which of the following chemical systems is/are nonaromatic? a. II b. IV c. II and IV d. None of the above A 8. Which of the following is the correct order of decreasing stability?

a. CH ΘC > CH2 = ΘCH > CHΘ3 b. CHΘ

3 > CH2 = ΘCH > CH ΘC

c. Θ2

ΘΘ3 CHCHCCHCH d. CH2 = Θ

3ΘΘ CHCCHCH

A

9. Which of the following statement is CORRECT regarding the inductive effect?

a. it implies the atom’s ability to cause bond polarization b. it implies the transfer of lone pair of electrons from more electronegative atom to the lesser

electronegative atom in a molecule

c. it implies the displacement of –electron from less electronegative atom to the more electronegative atom in a molecule

d. it increases with increase in distance A

10. Which of the following is the correct order of stability of following carbocation?

a. I > II > III > IV b. III > IV > I > II c. III > I > IV > II d. II > III > IV > I B

11. Which of the following is the correct order of increasing +M effect? a. b.

CH2

(I)

;

CH2

C N

(II)

;

CH2

OH

(III)

;

CH2

(IV)

CH3

O

>

NH2

>

OH OH

>

NH2

>

O

I III II

IV

H

B



c. d. A 12. Which of the following carbanion is least stable? a. b. c. d. C

Sol. Carbanion stability M

1

13. Which of the following position is reactive for electrophilic attack a. 1, 3, 8 b. 1, 3, 5 c. 10, 8, 6 d. 1, 3, 6 B 14. Which of the following compound is meta directing due to reverse Hyperconjugation effect. a. b. c. d. B 15. The compound

3

3

|

3

|3 CHH

CH

CH

CH

CCH have

a. Twelve 1° hydrogen atoms only b. Two 2° and twelve 1° hydrogen atoms c. Two 3° hydrogen atoms only d. Twelve 1°- and Two 3°-hydrogen atoms D

16. Which of the following resonating structures is most unstable? a. b. c. d. B Sol. (b) is most unstable because both parts of cycle are Anti aromatic

CH2 CH2

NO2

CH2

CH3

NH – C

1 2

3

4 5

O 10 9

8

7 6

CN CCl3 CH3 NO2

> >

NH2 O OH

>

OH O NH2

CH2

OCH3



17. The correct order of nucleophilicity is:

a. FOHNHCH 23 b. 23 NHCHOHF

c. 32 CHFNHOH d. 32 CHNHOHF

D 18. Degree of unsaturation in is: a. 2 b. 3 c. 4 d. 5 C 19. Arrange the (C–H) bonds x, y & z in decreasing order of their bond dissociation energies in homolysis.

a. y > x > z b. z > x > y c. z > y > x d. y > z > x B

Sol so bond dissociation energy order is E1 < E2 < E3 20. The functional groups present in Cortisone are: a. Ether, alkene, alcohol b. Alcohol, ketone, alkene, ether c. Alcohol, ketone, ester d. Ether, amine, ketone B 21. Which of the following alkenes is the most stable? a. b. c. d. C Sol. Conjugated dienes are most stable

CH2

CH2

H H x

H H

y

H

z

H x

H y

z

H

Highly unstable

Stable due to hyper conjugation

Stable due to resonance +

hyperconjugation

E3 E2

E1

CH3

HOH2C

O

O

OCH3

Cortisone



22. Which one among the following carbocations has the longest life?

a.

C)CH( 33 b. c. d.

B Sol. Maximum resonance 23. The type of isomerism exhibited by the component with formula C4H10O is/are

a. chain and position b. functional and position c. metamerism d. chain, position, functional and metamerism D

Sol. Alcohol & ether are functional isomer 24. Compound C4H11N can exhibit

a. Position isomerism b. Metamerism c. Functional isomerism d. All the three

D

25. Which among the following is likely to show geometrical isomerism?

a. CH3CH = CH2 b. CH3 – CH2 – CH = CH – CH3

c. CH3C(Cl) = C(CH3)2 d. CH2 = CH – CH = CCl2 B

26. The lowest Hydrocarbon which can exhibit geometrical isomerism is

a. Ethene b. Propane c. 1-Butene d. Dimethyl cyclobutane D

Sol.

27. The Z-isomer from the following is

(i)

5237

3

HCCCH||

HCCH

(ii)

7325

3

HCCCH||

HCCH

(iii) FCH

||BrCCl

(iv)

HCF||

BrCCl

a. only (i) b. only (iii) c. only (i) & (iii) d. both (i) & (iv) C 28. The possible number of alkynes with the formula C5H8 is

a. 2 b. 3 c. 4 d. 5 B

Sol. CHCH

CH

CCH

3|

3 ; CH3 – C C – CH2CH3; CH C – CH2 – CH2 – CH3

29. Which of the following exhibit geometrical isomerism?

a. CH2 = CClBr b. CH3CH = CCIBr c. CH3CH = CCl2 d. (CH3)2C = CClBr B

C

C

CH2 = CH – CH2

CH3

CH3

CH3

CH3



30. The most stable conformation of n-butane is

a. Skew boat b. Eclipsed c. Gauche d. Staggered D

31. The order of stability of the following carbocations is

P. 3HC

Q. 23 HCCF

R. 3

|

|3 CH

CH

CH

CCH

2

3

S. 2

|

|3 HC

CHCH

CHCH

CCH

32

32

a. P > Q > R > S b. S > R > P > Q c. Q > P > R > S d. S > R > Q > P B

Sol. The groups in the options given exert only inductive effect except in R, S exert +I effect. Q exerts –I effect. +I effect decreases the positive charge of carbocation. It becomes strong as size of alkyl groups increases. –I effect increases the positive charge of carbocation and destabilizes it so the

order of stability is S > R > P > Q. 32. Which of the following pair of structures represent the same compound?

a. b.

c. d.

A

33. An alkane (molecular weight 72) upon chlorination gives one monochlorination product. The alkane is

a. 2-Methylbutane b. n-Pentane

c. 2, 2-Dimethylpropane d. Cyclohexane

C

Sol. ClCH

CH

CH

CCHCH

CH

CH

CCH 2

|

|3

Cl3

|

|3

3

3

2

3

3

34. Which of the following alkene is most reactive in reaction with HBr.

a. (CH3)2C = C(CH3)2 b. CH2 = CH2

c. (CH3)2C = CH2 d. CH3CH = CHCH3

C

C = C

CH2 = CH

H H

CH3

, C = C CH2 = CH

H

H

CH3

H

H C = C

Cl

CH2Cl ,

H

H C = C

Cl

CH2Cl

C = C CH3CH2

H H

, CH3CH2

C = C

CH3

H CH2CH2CH3

H

CH3 – CH = CH – CH3 and

CH3



Sol. 3

|

3H

2

|

3 CH

CH

CCHCH

CH

CCH

33

3

3

333

CH

CHCH

CH

CCHCH

CH

C

CH

CCH /\

|

3H

3

||

3

35. In which of the following reactions Markownikov’s rule is not observed

i. peroxide Organic

23 HClCHCHCH

ii. peroxide Organic

23 HBrCHCHCH

iii. 223 BrCHCHCH

iv. HBr

322 CHCHCHCH a. i, ii b. ii, iii c. iii, iv d. i, iv

B Sol. Product is CH3 – CH2 – CH2 – Br (opposite to Markownikov’s Rule); Markovnikoff’s Rule is not obeyed

for symmetrical Reagent

36. Which of the following will show Tautomerism

(v) 522

||

3 HCOOCCH

O

CCH

a. i, ii, iii b. i, ii, v c. i, ii, iii, iv d. i, iv, v B Sol. 37. The order of activity of the various o- and p- director is

a. – O– > – OH > – OCOCH3 > Cl b. – OH > – O– > – OCOCH3 > – Cl c. – OH > – O– > – Cl > – OCOCH3 d. – O– > – Cl > – OCOCH3 > –OH A

(iii) (CH3)3C – CHO

(iv) O O

(i)

O = C – CH3

(ii)

O

O

OH

; CH3 C

O H

CH

C – OC2H5

O

(H-bond)

O = C – CH3 HO – C = CH2

;



38. Identify the correct order of reactivity in electrophilic substitution reactions of the following compounds a. 1 > 2 > 3 > 4 b. 4 > 3 > 2 > 1 c. 2 > 1 > 3 > 4 d. 2 > 3 > 1 > 4 C 39. In which of the following alkene intermediate carbocation rearrange on addition of HBr.

a. 2CHC\/

CH

CH

3

3

b. 2

|

3 CHCHH

CH

CCH

3

c. 2

||

3 CH

CH

CH

CH

CCH

33

d.

B

Sol. 32

|

3shif tH

3

|

3H

2

|

3 CHCH

CH

CCHCHHCH

CH

CCHCHCHH

CH

CCH

333

40. Which among the following statement is not correct?

a. 2CF

is more stable than 2CCl

b. 2CCl

is more stable than 2CH [triplet]

c. Singlet Carbene 2(CH )

is less stable than triplet carbene 2( CH )

d. Triplet carbene is biradical

B

Sol. 2FC

is more stable than 2ClC

due to stable back bonding 2ClC

is less stable due to –I effect of

Cl. 2HC

is less stable than 2( CH )

according to Hund’s Rule.

1 2

CH3

3

Cl

4

NO2

dr. sangeeta khanna ph.d 1 · a. position isomerism b. metamerism c. functional isomerism d. all...

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