READ INSTRUCTIONS CAREFULLY - Chandigarh · G:\Obj-Organic Chemistry Test - 1.doc AND BIOMOLECULES...

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Dr. Sangeeta Khanna Ph.D 1 CHEMISTRY COACHING CIRCLE G:\Obj-Organic Chemistry Test - 1.doc

ORGANIC CHEMISTRY AND BIOMOLECULES

READ INSTRUCTIONS CAREFULLY 1. The test is of 1 hour duration.

2. The maximum marks are 150.

3. This test consists of 50 questions. (Negative Marking)

4. For each question you will be awarded 3 marks if you have darkened only the bubble corresponding

to the correct answer and zero mark if no bubbles are darkened. Minus one (-1) mark will be

awarded for wrong answer

1. Which of the following shows the correct decreasing order of acidic nature?

a. RCOOH > H2CO3 > > HOH > ROH > HC CH

b. RCOOH > > H2CO3 > ROH >HOH > HC CH

c. > H2CO3 > RCOOH > ROH > HC CH > HOH

d. H2CO3 > RCOOH > > HC CH > ROH > HOH

2. Which of the following is correct order of Basic strength?

a. (CH3)2NH > (CH3)3N > CH3NH2 b. (CH3CH2)2NH > (CH3CH2)3N > CH3CH2NH2 c. (C2H5)3N > > d.

3. Which of the following will not give Hinsberg test

a. 3

|

|3 CH

CH

NH

CCH

3

2

b. CH3 – CH2 – CH2 – NH – CH3

c. d. both A & B

OH

OH

OH

OH

N

NH2

> NH3 >

N

N

O

N H

Dr. Sangeeta Khanna Ph.D


4. Which will not be formed in the following reaction?

a. b. c. d.

5. What will be the end product a. b. c. d. 6. Which of the following will be formed as a major product by Reduction of nitrobenzene in neutral

medium using Zn + NH4Cl

a. b. c. d.

7. The correct statement about the following disaccharide is:

a. ring I is pyranose with -glycoside link b. ring I is furanose with -glycoside link

c. ring II is pyranose with -glycoside link d. ring II is furanose with -glycoside link

NH2 NHOH NH2

OH

NO

CH2OH

H

O

H

H

OH

OH

H

HO

H

OH HO

CH2OH

O

H

CH2OH

H

OH H

HO

(I) (II)

NO2

OH

E

NO2

OH

E NO2

OH

E

NO2

OH

E

NO2

OH

E

NHCOCH3

Br

NH2

Br

Br

Br

NH2

Br

NH2

Br

NH2

A

NH2

CH3COCl B

Br2 + Fe H

+

C



8. on oxymercuration demercuartion produces:

a. b.

c. d.

9. CH3 – CH2 – OH A2I/P B

Ether

Mg DC

OHHCHO 2 . The compound D is:

a. propanal b. butanal c. n-butyl alcohol d. n-propyl alcohol

10.

The major product is:

a. b. c. d.

11.

The Product is: a. b.

c. d.

12. Which of the following will not give benzene?

a. Hexane

atm 20-10

K /773OCr

Δ

32

b. CaC2 Tube Iron hot Red )ii(

HOH )i(

c. d.

CH2 – CH – CH3

OH

CH2 – CH2 – CH2OH

CH2 – CHOH – CHOH CH – CH2 – CH3

OH

Na/NH3

H2(1 mol)/Ni ,

N = N – Cl

aq. C2H5OH

CH2CH = CH2

OH

(i) H3PO4/673 K

(ii) Heating with Cr2O3/Pt, H2 H



13. In the following reaction:

C7H8 BAFe/Br/Cl3 22

the compound ‘B’ is:

a. b.

c. d.

14. Consider the following structures. Which of the following statements is correct? a. I and II are enantiomers b. II and III are enantiomers c. II and IV are diastereomers d. I and III are enantiomers 15. The IUPAC nomenclature of

a. 1-Fluorocyclopentene b. 3-Fluorocyclopent-1-ene c. 1-Fluorocyclo-pent-2-ene d. 5-Fluorocyclopent-1-ene

16. The correct decreasing order of priority for the functional groups of organic compounds in IUPAC system of nomenclature is:

a. –CONH2, –CHO, –SO3H, –COOH , R

O

C||

b. –COOH, –SO3H, –CONH2, –CHO, R

O

C||

c. –SO3H, –COOH, –CONH2, –CHO, R

O

C||

d. –CHO, –COOH, –SO3H, –CONH2, R

O

C||

17. Correct stability order for the following species is:

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

18. Which of the following reaction confirms presence of aldehyde group in glucose?

a. formation of osazone b. Reaction with Red P + HI c. with NH2OH d. with NaHSO3

H3C Br Cl3C

Br

Cl

Cl

CH3

Cl Br

Cl3C Br

Cl H

I

Cl H

II

Cl H Cl H

IV III

O

(I)

(II)

O

(III)

(IV)

F



19. Which of the following is not correct?

a. b. c. d.

20. Which of the following compound does not give Laisaigne test of nitrogen

a. Hydroxylamine b. urea c. pyridine d. aniline

21. NH3 evolved by treatment of 0.3 gm of organic compound for the estimation of nitrogen, was passed in

100 ml of 0.1 M sulphuric acid. The excess of acid require 20 ml of 0.5 M NaOH solution for complete

neutralisation. Percentage of nitrogen in organic compound is:

a. 46.6% b. 60.3% c. 20.3% d. 80%

22. Which of the following is an example of chromoprotein

a. egg albumin b. Haemoglobin c. Nucleoprotein d. Keratin

23. Osazone formed by which of the following is the same substance:

(I) Fructose (II) glucose and (III) surcrose (iv) Mannose (v) Galactose

a. I, II & V b. I, III & IV c. I, II & IV d. I, II, III & IV

24. Isoelectric point of alanine is 6.1. Above 7 pH, the alanine molecule will occur as:

a. COOHH

CH

CNH

3

|2 b.

COOH

CH

CNH

3

|3

c. COOH

CH

CNH

3

|2 d. COOHH

CH

CNH

3

|3

25. Acetaldehyde & acetone can be distinguished by a. Bromoform test b. Solubility in water c. Tollen’s test d. DNP test

H3C CH

CH3

CH3

E

H3C CH CH3

CH3

E

H3C CH2 is more reactive than Benzene in electrophilic substitution & more reactive than alkane in free radical substitution

C – NH

O

E

C – NH

O

E +

C – NH

O

E

O

R O – C

O

Cl2/Fe R O – C

Cl (Major)



26. The conversion:

CH3CH = CHCHO CH3CH = CHCOOH

can be effected by

a. alkaline KMnO4 b. acidic K2Cr2O7 c. ammonical AgNO3 d. selenium dioxide

27. In the Cannizzaro reaction given below,

2 Ph – CHO OH

Ph – CH2OH + PhCO 2 , the slowest step is

a. the attack of – OH at the carbonyl group

b. the transfer of hydride ion to the carbonyl group

c. the abstraction of proton from the carboxylic acid

d. the deprotonation of Ph – CH2OH

28. The second step in the mechanism of imines formation is acid-catalyzed, yet the rate drops below at low pH.

Why does the rate drop below this pH?

a. The carbinolamine intermediate is stable at low pH.

b. The imine product is hydrolyzed at low pH.

c. Protonation of the amine decreases its nucleophilicity.

d. The amine is hydrolysed at low pH.

29. Consider the given reaction: C6H5–CH=CH–CHOC6H5–CH2–CH2– CH2OH

Which one of the following reagents can be used to bring about the transformation given above?

a. LiAlH4 b. NaBH4 c. H2/Pd – BaSO4 – CaCO3 d. Na/NH3()

30. What is the major product of the following reaction?

O3H

O2Et

MgI3CH3 NCCH

a. CH3 – CH2 – NH – CH3 b. 3

| |

3 CH

H/

N

CCH

c. 3

| |

3 CH

O

CCH d. OH

O

CCHCH| |

23

31. Which of the following is most reactive in nucleopilic addition reaction

a. b. c. d.

32. Rosenmund Reduction of Benzoylchloride with Pd + BaSO4 will give

a. Benzylalcohol b. Methylbenzene c. Benzaldehyde d. Benzoic Acid

CHO CHO

CH3

O = C – Ph CHO

NO2



33. What will be the product(R) of the given reaction:

RPCHCCHHCl

)Hg(Zn

OH

SOH,Hg3

2

422

a. Propane b. 1-Propanol c. Propanal d. Propanone

34. Which of the following will show tautomerism

a. CCl3CHO b. c. d.

35. :is reaction Cannizaro this of Product ,DCH%)50(

HO||O

a. DODCHCOD 22 b. 22 CODCOH

c. DOHCHCOD 22 d. OHCHDCOD 22

36. Column I (Reaction) Column II (Name) I. COCl CHO (i) DIBAL-H followed by Hydrolysis II. C N CH2 NH2 (ii) Clemmenson Reduction

III. 2

\

/\/ CHOC (iii) Rosenmund reduction

IV. C N CHO (iv) Mendius Reduction I II III IV I II III IV a. (iv) (ii) (iii) (i) b. (iii) (i) (iv) (ii) c. (iii) (iv) (ii) (i) d. (iii) (ii) (iv) (i)

37. Consider the following sequence of reactions.

O + H2NOH BAheat

4SO2Hheat

The product (A) and (B) are respectively a. b. c. d. 38. Which of the following statements is not applicable to enantiomers?

a. They have identical melting and boiling points b. They have identical chemical properties except towards optically active reagents c. They can be separated by fractional crystallization d. They rotate the plane polarized light in opposite directions but to the same extent.

39. sec-Butyl chloride obtained by free radical chlorination of n-butane is always

a. Dextrorotary b. Laevorotatory c. Racemic mixture d. None of the above

CH2 – CHO C

O

O O

OH

NHOH

and N – OH NOH and H

N = O

NOH and

O

N – H

NOH and

N – H

O

C



40. 2, 3-Pentadiene shows enantiomorphism, it

a. contains one chiral carbon atom b. contains two chiral atoms but the molecule as a whole is achiral c. does not contain any chiral carbon atom but the molecule as a whole is chiral d. none of the above

41. The tautomeric form of is

a. b. c. Both (A) and (B) d. None

42. The most stable carbocation among the following

a. b. c. d.

43. The IUPAC name of a secondary optically active alkyl halide having molecular formula, C5H11Br is

a. 1-bromopentane b. 3-bromopentane c. 2-bromopentane d. 1-bromo-2-methylbutane

44. What will be the final product in the given sequence of Reaction: a. b. c. d. none 45. How many optically active stereoisomers are possible for butane-2, 3-diol?

a. 1 b. 2 c. 3 d. 4 46. Which of the following is most stable conformer of 1, 2 dichlorocyclohexane?

a. b. c. d. All have equal stability

O

O O

NH HN

N H

OH

N N

N OH OH

O–

NH HN

N H

O– –

O

NO2

NH2 (i) NaNO2 + HCl

A HBF4

B mild

C

N2Cl 42BFN F

Cl

Cl

Cl

Cl

Cl

Cl



47. 22KOH .alc

|

|

|

|CHCHH

H

X

C

H

H

CH

X = F, Cl, Br, I The Rate of reaction is a. I > Br > Cl > F b. F > Cl > Br > I c. Br > Cl > F > I d. Cl > F > Br > I

48. What will be the product of following reaction a. b. c. d. No reaction

49. R)O(OHCHCHCHK 273

KMnO .dil223

4

Which of the following is not correct for R a. It has one Chiral Centre b. It give idoform test c. It has meso form d. It turns K2Cr2O7 organe to green

50. Linear polymerization of ethyne will give a polymer that conduct electricity. This polymer will have

structure:

a. n CCCHCH b. n CCCC

c. n CHCHCHCH d.

CH = N – C – NHNH2

O

CH = N – C – NH2

O

NH2

CH = CH

CH CH

CH CH

CH = CH

C = O + NH2 – C – NH – NH2

H O

CH = N – NH – C – NH2

O



ORGANIC CHEMISTRY & BIOMOLECULES (ANSWERS) +2

1. A 2. B 3. C 4. A Sol. The o/p-directing group ‘OH’ dominates over the m-directing group ‘NO2’. 5. C 6. B 7. A 8. A Sol. Oxymercuration demercuration is Markovnikov addition of water 9. D

Sol. CH3 – CH2 – OH )A(

23I/P

ICHCH2 HCHO

)B(23

Ether

MgIMgCHCH

)C(

|

|23 OMgI

H

H

CCHCH

H/OH2

)D(223 OHCHCHCH

10. C Sol. Na/NH3 is Birch reagent. The product is trans-product 11. A Sol. 12. C Sol. The product, here, is sodium phenate 13. B

Sol.

14. D 15. B 16. B 17. D Sol. (I) has 6 hyperconjugation structures and one resonance structure due to +M effect of O-atom.

(II) has 3 hypercojugation structures and one resonance structure. (III) has 5 hyperconjugation structures. (IV) has 2 hyperconjugation structures. 18. C 19. D Sol. In choice (a), dominance of hyperconjugation is responsible.

In choice (b) there are two Kekule structures and 9 ionic structure (3 ionic structure and per -H of CH3 group). In choice (c) NH group activates benzene ring

20. A 21. A Sol. meq. of NH3 = meq of acid taken – meq. of Base used = 0.1 × 2 ×100 – 20 × 0.5 mole of NH3 = meq of NH3 = 20 – 10

mole of NH3 = 2101000

10 mole

Percentage N = 1003.0

1410 2

= 46.6%

22. B 23. C

7 - H

4 - H

H2(1 mol)/Ni

CH3

3Cl2/

Sunlight

CCl3

Br2/Fe

CCl3

Br



24. C Sol. pH of solution is above 7, i.e., medium is alkaline. The – COOH group will forms its salt. The alanine

molecule at pH > 7, will exist as COOH

CH

CNH

3

|2

25. C 26. C 27. B 28. C 29. A 30. C

Sol. 3

| |

333

Θ

CH

MgBrN

CCH NCCH MgBrCH

31. D 32. C 33. A 34. B 35. C 36. C 37. D 38. C Sol. They cannot be separated by fractional crystallization because, they have the same solubility in any

particular solvent. 39. C Sol. sec-Butyl chloride obtained by free-radical chlorination is a

racemic mixture. Free radicals are planar species. Therefore, the attack of the Cl2 molecule on the intermediate sec-butyl free radical can occur from top or the bottom face with equal ease giving a 50 : 50 mixture of the two enantiomers i.e., racemic mixture.

40. C Sol. 2, 3-Pentadiene does not contain any chiral carbon atoms but the molecule as a whole is chiral. 41. C 42. C Sol. Both C and D are tertiary carbocations but D is less stable than C due to the presence of an electron

withdrawing group. 43. C

Sol.

activ e)optically ,2(etanBromopen2

3|

223 CHH

Br

CCHCHCH

44. C 45. B

Sol. Butane-2, 3-diol (CH3 - 3CHHOHCHOHC

) has two similar chiral carbon atoms. Therefore, like

tartaric acid it has three stereisomeric forms (d-, - and meso). Out of these only two (d- and ) are

optically active 46. B Sol. No repulsion at equatorial position. 47. A 48. B 49. C

Sol. R is 2

|

|3 CH

H

OH

CCH

It has only one chiral carbon, so it can’t have meso form. 50. C

CH3

C – CH2CH3

H

Cl2

Cl2

READ INSTRUCTIONS CAREFULLY - Chandigarh · G:\Obj-Organic Chemistry Test - 1.doc AND BIOMOLECULES...

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