Bansal Classes Organic Chemistry Study Material for IIT JEE (1)

ORGANIC CHEMISTRY XII (ALL)

QUESTION BANK ON

ACIDITY, BASICITY H-BONDING &

TA UTOMERISM

I

ACIDITY. BASICITY. H-BONDING & TAUTOMERISM

Q. 1 Write equations showing the Lewis acid-base reaction that takes place when (a) Methyl alcohol reacts with BF3. (b) Methyl chloride reacts with AICI3. (c) Dimethyl ether reacts with BF3.

Which of the following are lewis acids & which are lewis bases?

CH3

(a) CH3CH2-N-CH :

CH3

(d) : B r f

(b) CH3-C

CH3

*(e) (CH3)3B

(C)(C6H5)3P:

(f) m

^/C?. 3 Which would you expect to be the stronger acid? Explain your reasoning in each instance. ' CH2C1C02H or CHC^CO.H

,Jb) CC13C02H or CHC12C02H J t ) CH2FC02H or CH2FCH2C02H

Q. 4 Write equations for the acid base reaction that would occur when each of the following compounds or solution are mixed. In each case label the stronger acid & stronger base,& the weaker acid & weaker base.

(a) NaH is added to CH3OH (b) NaNH2is added to CH3CH2OH (c) Gaseous NH3 is added to ethyl lithium in hexane (d) NH4C1 is added to NaNH2 in liq. NH3 (e) (CH3)3CONa is added to H20 (f) NaOH is added to (CH3)3 C-OH (g) C2H5OH is added to a solution of HC = C~Na+ in liquid NHV

Q.5 CHjCHjMgBr + CH3C = CH >A+B

Choose the member of each of the following pairs of compunds that is likely to be the stronger base.

v (a) NH 2 or NH3 (Jb) OH orH20 J c ) O H or SH

Choose the member of each of the following pairs of compunds that is likely to be the weaker base.

o- O 4

H20 or H30 v, (b) H2S, HS- S2~

Jd^F- , OH~ MTV, CH3 J e ) HF, H20, NH3

(C) CI", SH , OH- SH", SeH

Q.8 Label the reactants in these acid - base reactions as Lewis acids (electrophiles) or Lewis bases (nucleophiles). Use curved arrows to show the movement of electron pairs in the recations.

->CH, - O ^ C H V + l C i r (A) CH3 O: + C H 3 - C I :

(b) C H 3 - O - C H 3 + : O - H > C H 3 - O : + C H ^ - P - H

CH3 H CH3 H

(c)

O II

H - C - H + :NH3 IS M

:o: 2 ->H-C=RH

NH3

(d)

(e)

(f)

CH3 - N H 2 + CH3 - CH2 - CI : - > CH3 - N H 2 - CH2CH3 + : C I :

(CH3)3CC1 + A1C13 > (CH3)3

19 Explain which compound is the weaker base.

NH2 NH2

rol^Ta ^ b f . CH2 = C H - C H = C H - C H 2 " or C H ^ C H - C I V

0 0 0 0 II II II II

J t f 0 - - C - C - 0 H or H O - C - C - O H

OH OH

j * ( o r * - [ o r " 1

Q. 20 Rank the following amines in increasing basic nature.

[OJ [ o r LO (i) (ii) * (iii) (iv)

NO,

NHt

N H .

NH2

0 f o r 1 " L Q CH3

(i) (ii) (iii) (iv) NH2

(c> (i) (ii) (iii)

Q. 21 Dimethyl furmamide (DMF) is an example of polar aprotic solvent, aprotic meaning it has no hydrogen atoms attached to highly electronegative atoms.

(a) Draw what you predict to be its most important resonance forms. (b) DMF when used as the reaction solvent, greatly enhances the reactivity of nucleophiles. e.g.

NaCN + CH3CH2Br > CH^CIi, C = N + NaBr Suggest an explanation for this effects.

Q. 22 Arrange the basic strength of the following compounds, (a) OH- CH3COO- Gi-

ft (ii) (iii) Or) C H e C " CH2 = CH- C H 3 C I V

(i) (H) (iii) ( p f CH2 = C H C R j N R , CT^CI^CI^ML, CH = C - C i ^ W ^

^ 0) Oi) d )

Q.13 Each of these molecules is nucleophile. Identify the nucleophilic atom & draw a mechanism for reaction with a generalised electrophile E+, giving the product in each case.

W R - C . C - w J X (ONH.-NH,

OMe I NH p IT

( d ) M e O / ÔMe (e) M ^ M e

^,-Q. 14 Arrange the following compounds in order of increasing basicity.

^ CH3NH2, CH3 NH, CH3NH

x & f " CH30- CH3NH-, CH3CH2

y j d f CH3CH = CH", CH3CH2 CH2 , CH3C=C

Q.15 Neither of these methods of making pentan-1,4 diol will work. Explain why not-what will happen instead?

(i) CH0-CH2-CH2-CH2-0H - M e M ^ > CH 3 -CH-CH 2 -CH 2 -CH 2 followed by H + | |

OH OH

(ii) Br-CH2-CH2-CH2-OH MgBr-CT^-CH^CHÔH f

CH 3 -CH-CH 2 -CH 2 -CH 2 I I

OH OH Q 16 Suggest what species would be formed by each of the following combinations:

(a) PhO - + CH3COOH

( b ) H N ^ N H + CH3COO-

(c) Pyridinium ion+trifluoroacetate ion

Q.17 Say which pka belong to which functional group in case of following amino acids: ^COOH

(i) cysteine: HS J : 1.8,8.3 & 10.8

N H 2

(ii) glutamic acid : H 0 2 C \ ^ \ ^ C O O H . 2 ]9> 4 25, 9.67

N H 2

Q.18 Record the following sets of compounds according to increasing pKa ( = - log Ka) OH OH

(a) C ^ J ' (ÔJ ' cyclhexane carboxylic acid.

^ b ) 1-butyne, 1-butene, butane Propanoic acid, 3-bromopropanoic acid, 2-nitropropanoic acid

)JfSf Phenol, o-nitrophenol, o-cresol Hexylamine, aniline, methylamine

NH2

^ LO (i)

V ^ O f O

NH-C6H5

(ii)

NH,

o

NH2

(i) ci-(i)

(ii)

RCOO- 0H-(ii) (iii)

Q.23 Set the following in increasing order of pk b :

(iii) NH,

CI (iii)

RO-(iv)

NH2-(v)

J

h' (iii)

J* Q.24

(a)

NH

ff N^H

CH3NH2 , (CH3)2 N H , (CH3)3 N , NH3 [In aqeous medium] NH

-NH2

Arrange the following in increasing acid strength:

o

= o OH

(i)

OH

O ,

(i)

O

CH3- OH

(ii)

O O

_ T-C-CH,

O f o

(iii) OH

CN

(iii)

0

C H 3 - C - O H

H 0 - C - C - 0 H H O - C - C H 2 C H 2 (ii) (iii)

O

J- OH

vyO .25 Set the following in increasing order of pka: j f f i Methane sulfonic acid, acetic acid & methanol.

{ CH3- CH2 - CH3, CH2 = CH - CH3 , CH3 - CHO , CHO - C H j - CHO , CH4 Ui) ^ ^ J f y CH 3 N0 2 , (N0 2 ) 2 -CH2, (N0 2 ) 3 -CH

n u 9 H OH 9 H OH X .

^ h o 2 N 2 -

^ J y ) CH3COOH, N 0 2 - C ^ - COOH, CH3 - C - CH2 - C - OH

o o . . CN CN

^ Q-Q-J& H H H H H CN

fafff CHO-CHL-CHO, C H 3 - C - C H 2 - C - C H 3 , E t - 0 - C - C H 2 - C - O - E t , ^ II II II II 0 0 0 0

Et - O - C - CH2 - C - CH3 II II 0 0

Q. 26 Cyanic acid (HO-CsN) & isocyanic acid (H-N=C=0) differ in the positions of their electrons but their structure do not represent resonance structures.

(a) Explain (b) Loss of a proton from cyanic acid yields the same anion as that obtained by loss of a proton from

isocyanic acid. Explain. i

Q. 27 Draw a mechanism for this reaction. PhCHBrCHBrC02H + NaHC03 > PhCH=CH-Br + C02

Q.28 Arrange the increasing order of acidic strength of the following compounds.

Col, v>r ^ rb CH,

(i) (ii) (iii) CH2C02H

(b) [QJ CH2=CH-CH2C02H C H ^ C O . H

(i) ()

x-(29 Explain which is a stronger acid. O O

^ a ) CH3CH3 BrCt^NO,, CH3 - C - CH3 & CH3 - C - CH2CN

OH .

^ C O ) or J d ) ( 0

O=C~CH3 ' O=C-CH3 CH3 SH OH

Mo)

^ Ammonium salts are much more soluble in water than are the corresponding sodium salts. Explain?

QS 8 HF has a dipole moment of 1.82 D, its boiling point is 19.34C. Ethyl fluoride has an almost identical diploe moment & has a larger molecular weight, yet its B.P. is -31.TC. Explain.

J&39 HC02H & CH3C02H exists as dimer. Explain.

Q. 40 Cyclohexanol is more soluble in water then 1 -hexanol.

Q. 41 Explain why CH3OH and CH3CIÔH are reasonably good solvents for many ionic compounds compare the solvent properties of ethanol and pentanol towards ionic compound.

Q.42 1,5-Pentanediol is soluble & 1-Pentanol is slightly soluble in IÔ.

\J#A3 Compare the relativî^ oiling points Water solubilities of toluene & phenol.

Q.44 Which isomer (o,m or p) ofhydroxacetophenone steam distills. J ^ 4 5 Give structure for ethanolamine showing two different intramolecular H-bonds & discuss their relative

strength. f

Q.46 Which of the following system show H-bonding during tautomerism.

O N - H

o ^ = v r v o . . N C ^ H H O a H

Q. 47 Trans isomer of indigotin is stable w.r.t cis isomer. Explain.

(a) OK M > 0 (b) Q (c) A ( d ) ( \ W W H HoXr

A Q. 4 8 What is the attacking site of conjugate base of triketo form of phloroglucinol in protic & aprotic solvent.

\JQC49 In each oftheôllowing pairs which is more stable:

H (I) (11)

O O C / 0 H C / O H

(I) ( n f C"3 (1) N"2 (J^NH 0

C / 0 H

u (11)

In each of the following pairs which is less stable: o o C /OH /OH

( I ) (11) U ) (ID

O

/ 0 H

(I) (II)

0 0 O OH II I! U X c c c c

(e) a / V NCH3 - cuf V ^CH2 3 a ) 3 3 a o

yjtf. 51 In each ofthe following pairs which is more stable:

o o f c r H o c c c c

caf \ H 2 / XCH3 CH^ N CH3 3 (I)2 (II) H O O L,

O^ a-0 0C__^0 fj CH, %

j 0 O ^ v w y ( i i ) o CH2

(1) (II)

CH,

g CH CH O7" " f

OH ... O CH, CH (IT) (1) ( I I )

d # 5 2 In each of the following pairs which is less stable:

,0 ' 1 OH

O O^ O OH (0 U (II) ^ H (I) (II)

Ph Ph Ph Ph

N \ ($fCH2 = CH - NH2 ^ CH3-CH ^0 ^ OH 2 (1) ^ (II) (I) (II)

= NH

Bansal Classes Q. Bank on Acidity, Basicity, H-Bonding & Tautomerism [10]

I

Q. 53 In each of the following pairs which will have higher enol content: O ^ C O O E t ft

i Jti) CHXHO and / C \ (b) C \ and ^ CH3 CH3 X C O O Et CH3 CH3

^ C O O E t ft ft

(c) C \ and COO Et CH3 CH2 OCH3

. FL FF " FL ' FL

v and / C \ / c \ ^ CH3 CH2 CH3 CH3 CH2 OCH3

0 0 0 0 II II II II (e) and

CH3 CH2 CH3 Ph CH2 Ph

Q. 54 In each of the following pairs which will have less enol content:

^ C ^ V V ( b ) C T a n d Q

and Q ^ ( ^ f a n d

J * ) CH2 - CHO and CH3 - CHO

CI

Q. 5 5 In each of the following pairs which will have higher enol content:

II O c 11

CH2 -CHO and CH2 -CHO (b) (qY \ r and y\ I I 3 CH3 CH3 NO2 CI

(c) [OJ CHO and[OJ^ CHO OH 0 H

o o 0 0 c r

A A j / \ / \ v > 0 / \ / \ and CH3 CH CH3

CH3 CH2 CH3 ^ 2 H 5

( Bansal Classes Q. Bank on Acidity, Basicity, H-Bonding & Tautomerism [11]

In each of the following pairs which will have less enol content:

\ / O C H 3 V / O C H :

(a) 0 ^ 0 -"Sr

O ^ C P a n d C P J d ) h > = 0 and h > 0 0 0

r. TjJ^0 and ^ ^ o H H

57 Which of the following compounds can exhibit tautoimerism: (a) CHj = C = O (b)CH2 = CH-0H (c)HO-CH = CH-OH

(d) CH3CN (e) C \ ^NO2 8 Which of the following compounds can not exhibit tautoimerism:

0 O II o

(d)(6r0^ (e)@rH Which ofdie following compounds can exhibit tautoimerism:

NH 0

Which of the following compounds can not exhibit tautoimerism:

f y r ^ OMe

(d) Ol I OJ (e) CH3 - NO 61 what is the relationship between these two molecules? Discuss the structure of the anion that would be

formed by the deprotonation of each compound.

11->A I JL N5" "OH H

Q. 62 5,5 - dimethylcyclohexane -1,3 -dione (dimedone) shows tautomerism.Write down tautomeric structure.

Q. 63 Draw enol forms of these carbonyl compounds and comment on the stability of the enol forms.

(a) " o a > o o o

Q. 64 The proportion of enol in a sample of the two ketones below are shown. Why are they so different ? O O

4 x % enol (b) ( ^ J ^

C H B O ^ ^ - X ^ M I - CH = CH2

Q.65 (a) Jf J

and CH = CH2

(C) ( g r v ^

(1) NO, ( L I )

o (111)

CI

u ^ L Q j o

o

(II)

NO 2 (111)

O Ct I

N O ,

(11) o

(III)

Q. 69 In each of the following sets of compounds write the decreasing order of % enol content.

O

(a) 0 C O (I) (II)

( S Q ail)

0 (i)

j y a)

o

(II)

(11)

o (III)

o

(III)

o

0 (IV)

c r N (IV)

o j y o o. (d) ^ H (1)

(e)

o

a)

(ii)

o

(II)

(HI)

(HI)

N" H

(IV)

O

(TV)

( S | Bansal Classes Q. Bank on Acidity, Basicity, H-Bonding & Tautomerism [14]

Q. 70 Enol form of cyclobutanone is very unstable vs enol form of triketocyclobutane, which is very stable.

Q.71 ^ A ^ ^ A ^ has lower boiling point than even when former has - OH group.

O O A A a A

Q-72 C H { N C H 3 C D 3 / X C D 3 CH3 \ N 2 Y X C H 3 (i) y do (in)

Among these give ease of enolization.

Q. 73 % enol content of acetylacetone in following solvents is found as: Solvent % enol content HjO 15 Liquid state 76 hexane 92

92 Explain the observation.

@ @ Q.74 J k ^ ? +

(Minor) (Major)

Na0Hl[,H20 O

OH , OH

(Major) (Minor)

Explain the observation. O OH

This tautomeric system exist almost exclusively in favour of phenol and it is insensitive to change in solvent.

ANSWER KEY

Q.2 LA b,e LB acdf Q.3 (a) 2; (b) 1; (c) 1 Q . 5 CH3CH3 + C H 3 C s C M g B r Q.6 (a) 1; (b) 1; (c) 1; (d) 1; (e) 2; (f) 1 Q.7 (a) 2; (b) 1; (c) 1; (d) 1; (e) 1; (f) 3 Q. 11 (a) 1; (b) 1; (c) 1; (d) 1; (e) 2; (f) 2; (g) 2; (h) 1 Q.14 (a) 22>1>3; (c) 4>3>1>2; (d) 1>3>4>2; (e) 3>2>4>1 Q.72 3>1>2

4g Bansal Classes Q. Bank on Acidity, Basicity, H-Bonding & Tautomerism [16]

BANSALCLASSES TARGET IITJEE 2007

i

ORGANIC CHEMISTRY XII (ALL)

ALCOHOL & ETHER

CONTENTS EXERCISE-1(A) EXERCISE 1(B) EXERCISE-II EXERCISE-III

EXRECISE - IV(A) EXRECISE - IV(B)

ANSWER KEY

EXER CISE-IfA)

Q. 1 Which of the following reaction is called as 'Bouveault-Blanc reduction' (A) Reduction of acyl halide with HyPdBaSC^ (B) Reduction of ester with Na/C^OH (C) Reduction of anhydride with Li A1H4 (D) Reduction of carbonyl compounds with Na/HgHCl

Q.2 Glycol on treatment with PI3 mainly gives-(A) Ethylene (B) Ethylene iodide (C) Ethyl iodide (D) Ethane

Q.3 Acrolein is formed when glycerol is heated with-(A) Acidified KMn04 (B) Br2 water (C) KHS04 (D) HN03

Q. 4 Glycerol on treatment with oxalic acid at 110C forms-(A)Allyl alcohol (B) Formic acid (G) C02 and CO (D) Glyceric acid

Q. 5 If the starting material is 1-methyl-1,2-epoxy cyclopentane, of absolute configuration, decide which one compound correctly represent the product of its reaction with sodium methoxide in methanol.

Q. 6 When phenol is treated with PC15, the yield of chlorobenzene is generally poor because of the formation

(A) Benzoyl chloride (B) p-chorophenol (C) o-chlorophenol (D)Triphenyl phosphate

Q. 7 In the following reaction, final product is

of

14 CICH2CH-CH. 2 NaOC2H<

14 14 (A) CICH2CHCH2OC2H5

OH

(B) ClCH2CHCH2ONa

14 14 (C) CH2-CHCH2OC2H5 (D) CH2-CHCH2OC2H,

fe Bansal Classes Alcohols & Ethers [13]

Q. 8 Consider the reaction of HI with the following:

0 0 Which forms di-iodide on reaction with HI (excess)? (A) I and II both (B) II only (C) I only (D)none

Q. 9 Ethanol on reaction with acetic anhydride gives (A) Acetic ester (B) Formic ester (C) Ethanoic acid (D) Acetic ester and Ethanoic acid both

Q. 10 Ethanol cannot be dried by anhydrous CaCl, due to formation of the following solvated product (A) CaCI2-2C2H5OH (B) 2CaCl2-3C,H5OH (C) C a C l ^ C ^ O H (D) CaCl2-C2H5OH

Q.ll Rate of hydration of

will be in order: (A) I < II < III (B) I < III < II (C) II < I < III (D) III < II < I

Q . 12 The reaction of CH3OC2H5 with HI gives (A)CH3I ~ (B)C2H5OH (C) CH3I + C2H5OH (D)C2H5I + CH3OH

Q.13 The number of methoxy groups in a compound can be determined by treating it with (A) HI and AgNO, (B) Sodium carbonate (C) Sodium hydroxide (D) Acetic acid

Q. 14 Most acidic alcohol out of following compounds is (A) (CH3)3C-OH (B)CH3CH2OH (C)CH3OH (D)PhOH

Q.15 Action ofHN02 on CH3NH2 gives following as major product (A) CH3OH "(B) CH3-0-CH3 (C) CH3-0-N=0 (D)CH3-N02

Q . 16 A compound 'X' with molecular formula C3HgO can be oxidised to a compound' Y' with the molecular formula C1H602, 'X' is most likely to be (A) Primary alcohol (B) Secondary alcohol (C) Aldehyde (D) Ketone

Q.17 Diethyl ether and air gives ether hydroperoxide. The mechanism of the reaction is (A) Nucleophilic substitution (B) Free radical addition (C) Free radical substitution (D) None of the above

Q.18 Ether on carbonylation gives (A) Alkanoic acid (B)Alkanone (C)Alkylalkanoate (D)Alkanal

Q. 19 I 0 R - O- R > RI + R'OH true about this mechanism i

H

(A) SN1 in gas phase (B) SN2 in aqueous phase (C) both of the above (D) none

Q 20 Phenol with Hinsberg's reagent gives (A) Sulphone (B) Sulphanilic acid (C) Sulphonic ester (D)Sulphonal


0 .21 Select the odd structure out (A) CH3-CH(OH)-CH2-CH3 (C) CH3-CH(OH)-CH3

, KHSO, * LiAlH4 Q.22 Glycerol A

A and B are : (A) Acrolein, ally! alcohol (C) Ally] alcohol, acrolein

(B) CHrCH(OH)-CH2-CH,-CH3 (D) CH3-CH2-CH(0H)-C2H5

(B) Glyceryl sulphate, acrylic acid (D) Only acrolein (B is not formed)

Q 23 An ether is heated with phosphorous penta sulphide to give (A)Alkanthiol (B) Dialkyl sulphide (C) Hydrogen sulphide (D)Thioester

Q.24 Phenol A H + / H 2 > B ^ C (ii)C02/140C CH3COOH,A

In this reaction, the end product C is: (A) salicylaldehyde (B) salicylic acid (C) phenyl acetate (D) aspirin

Q.25 In the Liebermann's nitroso reaction changes in the colour of phenol occurs as: (A) Brown or red-greenish red-deep blue (B) red-deep blue-green (C) red-green-white (D) white-red-green

Q.26 ^ A. 'A'is

CH2OH CH2OH

(C) CH,

7 r> c H 3 Q.27 I ^ I J alkaline K M N 0 4 " ACOH A and Bare:

cold v CrO, > A > B

(A)

(C)

.CH, CH, OH J ^ ^ O L L O H ' I J = 0

CH3 CH3 OH OH ' OH

(D) no formation of A and B

fa Bansal Classes Alcohols & Ethers [36]

Q.28 B * NaBH, r v A and Bare:

(A) ( V CH2CH2CH0, ( / - C H =

CH = CH - CHO H 2 / P t > A

CH-CHJOH

(B) ^ / - CH2CH2CH2OH, J - CH = CH - CH2OH

( V CH= < (C) J - CH= CH-CH2OH in both cases

(D) CH 2CH 2CH 20H in both cases

CH,

Q.29 B 4r CH,OH C H . - C - C H , h218 > a CH,ONa \J " H+

o

A and B are

CH, CH, l 3 ~ 3

( A ) C H , - C - C H , , C H 3 - C - C H 2

18 OH OH OH OCH,

CH, CH,

CH, CH,

(B) C H 3 - C CH2 , C H 3 - C - C H 2

OH OCH, OH l gOH

CH, CH,

(C) CH3 - C - C H , , CH, - C CH, (D) C H , - C CH, , CH, - C CH,

IB OH OH 0 OH 1 8 OH 3OH 1 8OH OCH3 OH

o

Q.30 Oxalic acid + A >

henceA

(A)

^ B , B i s :

(B) 0 = ^

( C ) C H 2 - 0 - C H 2 (D) None

OH OH


' CH2CH3 rH=PH_

K0H

Q.31 CH2CH2OH

Select schemes A, B, C out of I acid catalysed hydration II HBO (A) I in all cases (B) I, II, III

Q 32 Dehydration of the alcohols

!IS oxymercuration-demercuration (C) II, III, I (D) III, 1, II

-OH OH

(II) OH

(III)

-OH

(TV) (I)

will be in order (A) IV > III > II > I (B) I > II > III > IV (C) IV > II > III > I (D) II > IV > I > III

Q 33 CI-LMgBr ^ A R M g / e t h e r > r. H I F, H , 0 +

E is

(A) (B)

CH3 CH2I

OH OH

Et

Q.34

CH2CH3

H+ ^ ? Product is:

( Q

(A)

CH,

(D)

CH,

Me o Ox / E t

Q 35 H \ 0 / \ / \ / CI Ale. KOH > Major product is

(A) H \ 0 /V^/ U \ (B) H \ q A A (C) H \ 0 / \ / \ (D)CJ x r

fa B a n s a l Classes Alcohols & Ethers [36]

o

Q.36 RMgX

R' H2O ? Product Obtained is:

R"

R R ' R R

( A ) R ' - C - C H 2 O H ( B ) R C H 2 - C - 0 H ( C ) R ' G H 2 - C - O H ( D ) R " C H 2 - C - O H R " R " R " R '

Q.37

0 O H

(A)

R H I,/NAOH , . . . C H , 2 ^ H + ^ A ) A, A IS

0 0

pr (C)

o II C-OH

(D)

o II

C s ~ O C H ,

Q.38 (A) < C H 3 H H2SO4 " * ( B ) A & B are:

(A) \H CP3 \H ? P H 3

&

(C)

H.CO OH OH c h 3

& H OH MeO CH3

\H Of ( B ) yj( &

H3CO CH3 HO CH3

H OCH,

CD)" & H3CO OH H3CO OH

Q.39 OCOCH3 AICI3 > 7 Major Product is:

(B) H 3 C O C

()\Or\Oy~OH COCH,

O-CH2CH=CH2

Q.40 Y Q Y ^ A , ? Product is:

(A)

OH /R

(B)

OH R \ / /R

CH2CH=CH2

OH

CH2-CH-CH7

R V A / R

(c) iJSi CH2CHCH9

(D) no reaction

Q.41 OH

(i)CHCS3+KOH

OH (ii)CH2I2+NaOH

OH

[X] here 'X' is:

(A) j c g f HOOC' ^ XOH O H C / \ ^ N O H

OHC (C) l O l / H : (D)

OHC

OCH3

OCH3

/OH OH Q.42 Inthisdiol

(A) OH at C2 is more basic than that of at C5 (B) OH at C2 is more acidic than at C5. (C) both have same basicity (D) both have same acidic strength

Q.43 (CH3)2C = C(CH3)2 A 0H~ > B H,O

(A) (CH3)2C-C(CH3)2

O

(C) (CH3)2C-C(CH3)2 I I

OH OH

OH CH2-NH,

NaNO, Q.44 | | > A

(B) (CH3)2C-C(CH3)2 I I

OH CI

(D) None

HCl

A is

(A)

OH CH-,-OH OH CH2-C1 OH CH2-NO, Q

( C ) f l ( D ) f S (B)

i&Bansal Classes Alcohols & Ethers fSJ

Q.45 CH2 =CHCHCH2CH2OH - Mn0-- ) A . A i s

OH

(A) CH2 = CHCCH2CH2OH (B) CH2 = CHCHCH2CHO

O OH

o

(C) CH. = CHCCHCHO I! o o

(D) CH2 = CHCCH2COH

^ . HCO,H . H,0+ , PthalicAnhydride Q4b Acetophenone 2> A 2 > B + C ; > Indicator (D)

C & D are

( A ) C H 3 O H & ( ^ X c > < J

(C) PhOH & HO. o

OH K

C-

V - l o

( B ) P h O H & [ 0 X K /OH

(D) CH3OH & [ O

OPh II 0

o II

C-CH3

C-CH3 II o

Q. 47 m-Aminophenol on treatment with NaOH and C0 2 gives which of the following as major product?

COOH

(A) H,

OH

(B) L J (C)

COOH

OH f ^ Y H

X O O H ( D ) ^ Y ^ C O O H NH,

Question No 48 to 50 (3 questions)

500C

LiAlH4

No reaction

NaBH, COOH

Q.48 Compound 13'is?

(A)' (B) ^ J - C O O H (C) ^ e ^ - C H 2 - O H (D) ( ^ T n j h c i i j


Q. 49 Organic compound A does not undergo de carboxylation reaction because? (A) Intermediate does not follow Saytzeffn rule (B) Intermediate does not follow Hofmanris rule (C) Intermediate does not follow Bredict's rule (D) Intermediate does not follow MarkwoniKoffs rule

Q. 50 Total No. of stereoisomers of B are? (A) 2 (B)4 (C)3 (D)6

EXERCJSE-I(B) Q. 1 Compound which gives alcohol on reduction is/are 0 0

I I II (A) Me - C - CI (B) M e - C - N H , (C) Me-CH-CH 2 (D) M e - C - O C - M e

II II " O o

Q.2 Phenol and ethanol are distinguished by the reaction with (A) Red litmus (B) NaHCO, (C) FeCl3 (D)NaOH

Q. 3 In the reaction sequence, CaC2 H2 > A d l ' B C , true about the product C is

(A) give yellow ppt. with NaOI (B) its final oxidation product is carbonyl compound (C) its final oxidation product is C02 and H20 (D) its final oxidation product is CH3COOH

Q.4 Which can be cleaved by HI04?

0 0 OHO II II I H

(A) CH3CH2CCH2CCH3 (B) CH3CHCCH2CH3

0 0 , , 11 11 (C) y / , ( (D) CH3CCH2CHCH2CCH3

OH ''OH \qh

Q 5 HBO, oxymercuration-demercuration and acid catalysed hydration will not give same product in

O (cO (dO (B) Q. 6 Diethyl ether reacts with PCP5 to form

(A) Ethyl chloride (B) Phosphorous oxy trichloride (C) Ethenol (D)Ethene


Q.7 Select the correct synthesis products

(D) ( C ^ B r + (CH3)3CONa > ( C H 3 ) 3 C O - ^ o )

Q.8 The molecules of ether dehydrates in the presence of-(A)A1203 (B)H3P04 (C)H2S207 (D) liq. NH3

Q.9 Anhydride of alcohol is (A) Ether (B) Aldehyde (C) Alkyl hydrogen sulphere (D) Alkene

Q. 10 Lucas test is used to make distinction between 1, 2 and 3 alcohols R O H + H C 1 anhydrous ZnCl2 > R C j | + H 2 0

c 0 n c - White turbidity

This shows that (A) ROH behaves as a base (B) greater the value of pKa (alcohol), greater the reactivity with conc. HC1 and thus sooner the formation

of white turbidity. (C) alcohol which reacts fastest with Na metal, will give turbidity at fastest rate (D) alcohol which gives red colour during Victor Mayor test, will give turbidity at slower rate then those

giving blue or white colour during Victor Mayor test.

Q. 11 If ethanol dissolves in water, then which of the following would be done (A) Absorption of heat (B) Emission of heat (C) Increase in volume (D) Contraction in volume

Q. 12 Which method is useful for the synthesis of ether?

(D) (CH3)3CBr + CH3CH2ONa

Q.13 Which of the following can react with TsCl (A) Glycerol (B) Oximinoacetone (C) Oil ofwintergreen (D) dimethyl amine

(!Bansal Classes Alcohols & Ethers [U]

Q. 14 Which is/are correct statements? CH3 CH3

\ / CH 3 OH (A) /Urn H2S4 H 0 T CH3

nucleophile attacks here when epoxv linkage is cleaved

CH; CH; rm \ / ( D J ,\~~K CH,OH

H | O CH3

nucleophile attacks here when epoxy linkage is cleaved

O /

(C) This is only affected in reduction to 2 alcohol

O " H+

( D ) R-C^OH + HtO-R

I These bonds undergo cleavage in the reaction

Q.15 3 -methyl-3 -hexanol can be prepared by (A) CH3MgI and 3-hexanone, followed by hydrolysis (B) C2H5MgI and 2-pentanone, followed by hydrolysis (C) C3H7MgI and 2-butananone, followed by hydrolysis (D) C4H9MgI and propanone, followed by hydrolysis

Q 16 In which cases product formed are not according to reaction?

NO, (A) ^ ^ - O H + HNO3 h 2 s 4 >

(B) ( ^ y ~ 0 H +HN0 3 h 2 s 4 ? Q - O N O .

(C) CH2 = CH-CHO + LiAlH4 -> CH3 CH,CH2OH

(D) ~ -Cl + CH3ONa > -OCH

Q.17 Dehydration of alcohols take place more rapidly with POCl3 than with H,S04. Select the correct statement(s) about the following dehydration reaction.

I s . j ) pyridine

(A) It does not involve carbocation. * (B) It involves R-OPOC1, with - OPOC1, as a better leaving group. (C) It involves E2 mechanism as pyridine base abstracts proton from the adjacent carbon as the same time at which - OPOCl2 is leaving. (D) It is E1 reaction without formation of carbocation.


Q.18 Which of the following will get oxidised by Br2 / KOH into carboxylic acid?

(A) CH3-CH2-OH (B) CH - CH3

OH

(C) ( ^ y - C H 2 O H (D) Q < S C I I ,

Q. 19 In Kolbe-Schmidt reaction, o-hydroxy benzoic acid is predominantly formed. This is because (A) salicylate anion is a stronger base than phenoxide ion (B) salicylate anion is a weaker base than phenoxide ion (C) p-hydroxy benzoate ion is a stronger base than phenoxide ion (D) p-hydroxy benzoate ion is a stronger base than salicylate ion

Q. 20 Methanol can be distinguished from ethanol by (A) Heating with I2 and alkali (B) Treating with schifFs reagent (C) Treating with Cr03 solution in dil. HjSO,^ (D) Treating with Lucas reagent

Q.21 Products form by following reactions are O H

A .

C H ,

O H

C H O

O H O H

C A ) ^ ( B ) ^ c h o (C) ^ .(D) C H 3 C H 3 C H 3 C H O C H

Q .22 For the reactions shown below, identify the correct statements) with regard to the products formed:

(i) p h * > \ y 0 p (h) p h ^ \ 7

(A) P and Q are identical (B) P is recemic and Q is optically active (C) P and Q are positional isomers (D)hoth are optically active

Q.23 C,NSNH, Tilden > (i) NH? > (ii) (iii). The product (iii) can be reagent HC1

(A) Alcohol ' (B) Ether (C)Alkyl chloride (D) Alkyl nitrite


Q 24 Products form during dehydration of following alcohols are

(A)f ] (B)( ) (C)|

Q. 25 Consider the following compound A (below)

\ / .OH

cy \ > H Select the correct statement(s) (A) It is more acidic than CH3OH (C) It reacts very fast with Lucas reagent

Q. 2 6 Match the following: Reaction

(A)

(B)

(C)

OH

CH=CH? "

CH2~OH

OH

CH3CH3 3 H

OH > heat

O-CH,

Q.28 Match the column: Column I

(A) Oxidation of 1 alcohol in aldehyde

(B) Cr03 L U .HC1 N'

(C) Cr0 3 .2 N

(D) Oxidation of alkene into acid

Q.29 Match the products of following: . Column I

(A) < 0 > 0 - C , 2 ^ 0 >

(B) Violet color is obtain by the

reaction of neutral FeCl3 with

(C) Reaction ofbenzaldehyde with

LiAlH4/H20 gives

(D) f n l + K i > ?

Column H (P) KMn04/A

(Q) Collin's reagent

(R) Jone's reagent

(S) P.C.C

Column II

(?) ( 0 > i (Q) { o > C H 2 -

(R)

OH

OH

(S) < O V C H 2 - I

Q.30 CH, - CH - CH = CH2 ReageatR^ Alcohol I CH3

which is true about alcohol and R? Alcohol

(A) CH , - CH - CH2 - CH2OH " I

CH,

(B) C H 3 - C H - C H ^ C H 3

I I CH3 OH O H

( O CH 3 - -C-CH 2 CH 3

CH3 O H

(D) C H 3 - C - C H 2 C H 3

CH3

Reagent

B 2 H 6 , H 2 0 2 / N a 0 H

PdCl2, H20, 0 2 / LAH

Hg(OAc)2 H^O / NaBH4

dil. H2S04


EXER CISE-II

Q. 1 What reagents could you use for the following conversions (a) MeC0(CH2)0C02Et -> MeCH0H(CH2)2C02Et (b) H 0 2 C ( C H 2 ) 4 " C 0 C r - > H 0 2 C - ( C H 2 ) 4 C H 2 0 H (c) 02N(CH2)2CN -> 02N(CH2)2 CH2NH2 (d) 02N(CH2)2 CH = CH2 -> H2N(CH2)2CH=CH2 (e) Me2CHCOCl -> Me2CHCHO (f) 02N(CH2)3CH0 02N(CH2)3 CH2OH (g) 02N(CH2),CH=CH2 -> 02N(CH2)3CH3

Q.2 Following compounds undergoes reaction with Mn02. What are the products in each case? (a) CH3CH2CH=CHCH20H (tyPhCI^OH (c) PhCH(OH)CH2CH2OH

(d)MeCH=CH(CH2)3OH (e) [ ^ > - O H

Q. 3 Carry out the following conversion

/ v C H 0 Br Acraldehyde

(i)

(iii)

(iv)

(v)

Br - CH, CHO

CO,Et

CH 2 - C H 2 C H O

- /CHO

MeO' Glyceraldehyde Ph CHOH CH2 CHO

O

-CH2OH

Glyceraldehyde

CI

Q. 4 Outline a mechanism to account for different isomer formed when Me2 C CH2 reacts with CH3 OH N o /

in acidic and in basic medium.

Q. 5 Find the structures of A to F.

Q.6

mild D ^ ^ C I L C O J I C6H120

(A)

Product

Explain product formation. How two OH groups behave differently.

Q.7 R2C = O + Et3Al -> C2H4 + R2CHO AlEt2 Suggest a mechanism for the reaction.


Q.8

OH

TsCl Pyridine

NaBr Mg

dry ether

What are A to E?

D - S 2 - B 1.CHJCHO 2. HjO

Q. 9 Identify A to E in the Mowing reactions.

(i) Me2CO+A H+

(i)

(iv)

Me2C. \ o - J

MeCHO + HOCH2 CH2 SH

1.HCO3H

2 . H 2 0

Q. 10 What are the order of rates of oxidation with HI04 of the following diols. Explain with reasons. (a)Me2C(0H)C(0H)Me2 (b) Me2C(OH)CH (OH) Me (c) CH2(OH) CH2 (OH) (d) Me CH(OH) CH (OH) Me

Q. 11 t- Butanol in presence of fenton's reagent forms 2,5 dimethyl hexane 2,5 diol as one of the product. Explain with the mechanism.

Q. 12 How you distinguish the following compounds? (a) t butyl alcohol & n butyl alcohol (b) ethyl alcohol & n propyl alcohol (c) allyl alcohol & n propyl alcohol (d) benzyl methyl ether & benzyl alcohol

Q.13 Differentiate: (a) 1 -Hexanol and 1 -chlorohexane (c) Diethyl ether and n-pentane

(b) Diethyl ether and n-butanol

Q.14 Explain: (a) No est erifi cation takes place between ethyl alcohol and excess of sulphuric acid at 170C. (b) Sodium chloride solution in water is added to decrease the solubility of organic compounds in water.

Q.15 Predict A, B & C.

CH3OH - P+L2 > A + C

Q. 16 Carry out conversion of methyl alcohol into ethyl alcohol and vice versa.

^Bansal Classes Alcohols & Ethers PV

Q.17 Arrange the compounds (i) Ethanol, propane and 1-pentanol, (ii) Butane 1,2,3-pentanetriol and butyl alcohol, (iii) Pentane, 1 -pentanol and 1 -hexanol, on the basis of (a) in order of increasing boiling points and (b) in order of increasing solubility in water.

Q.18 Complete the following equations & comment:

(iii) Me2C = CH2 ^ ^ o > ? pressure

Q. 19 Complete the following equations: (i) n - C3H7 - C02H > n - C4H9OH

(ii) Me2CO + EtMgl ? H+ > ?

(iii) EtC02Et + 2MeMgI > ? > ?

( /=CHCO,Et \ = C T T T T Mn0? (iv) ^ //=CHC02Et > ^ ^=CHCH2OH

Q. 20 t-butyl alcohol reacts less rapidly with metallic sodium than the primary alcohol. Explain why?

Q. 21 Diethyl ether behaves as base. Why?

Q. 22 What is the significance of proof spirit?

Q. 23 Sodium metal can be used for drying diethyl ether but not for ethanol. Why?

Q.24 Sometimes explosion occurs during distillation of ether sample. Give the reason.

Q. 2 5 Ethyl alcohol is denatured with methyl alcohol. Why?

Q.26 C2H5I A - 2 4 > B A g 2 0

Q. 27 Ethyl alcohol reacts with HI but not with HCN. Explain why?

Q. 2 8 Write the structure of the principal organic product formed in the reaction of 1 -propanol with each of the following reagents:

(i) Potassium dichromate (K2Cr207) in aqueous sulfuric acid, heat 0 II

(ii) Acetic acid CHXOH in the presence of dissolved hydrogen chloride.

(iii) CH3 y~S02Cl in the presence of pyridine

O O (iv) C6H5COCC6H5 in the presence of pyridine


o

(v) m P r e s e n c e pyridine

Q. 29 Complete the following series of equations by writing structural formula for compounds A through I:

^ J j C 5 H ? C 1 (a) \\ // HCl C H fJ NaHC3 ) C H O ^ ^ > C H O \ \ / / > S 7 ^ 5 8 H 2 S 0 4 , H 2 0 5 6

Compound A Compound B Compound C

(b) CH, = CHCH,CH,CHCH, SOC'2 > C,H,,C1 ^ > r HXIO NaB"4 >CH,,( 1 I p y r i d i n e ( i i ) Z n / H 2 0 5 ^ 5 1 1

OH (D) (E) (F)

(c) ^ ^ N ^ P H > Compound G Compound H > Compound I * ' ' ' CH,C1,

e.

heat

Q. 3 0 Predict the principal organic product of each of the following reactions. Specify stereochemistry where appropriate.

/Br (a) - ^ ( A )

methanol

H ; C

(b) I | > + CH3ONa CH3H >(B)

C H 2 C 6 H 5

(c) ( V C H - C H 2 W V (d) CH3(CH2)16CH2OTs + CH3CH2CH2CH2SNa > (D)

Q. 31 Deduce the identify of the missing compounds in the following reaction sequences. Show stereochemistry in parts (b) through (d).

(a) CH2 = CHCH2Br compound A(C4HgO) > compound B(C4HgBr20)

( i i i ) H , 0 + g

DC

compound D < compound C (C4H7BrO)

COoH

(b) Cl - H ( 1 ) 4 > compound E (C3H7C10) K 0 H 'H2 > compoundF (C3H60)

CH, '

^Bansal Classes Alcohols & Ethers [19]

Q. 3 2 Choose the reaction in each of the following pairs that proceeds at the faster rate. Explain your reasoning. (a) Base-promoted hydrolysis of phenyl acetate or m-nitrophenyl acetate (b) Base-promoted hydrolysis of m-nitrophenyl acetate or p-nitrophenyl acetate (c) Reaction of ethyl bromide with phenol or with the sodium salt of phenol. (d) Reaction of ethylene oxide with the sodium salt of phenol or with the sodium salt of p-nitrophenol (e) Bromination of phenol or phenyl actetate.

Q. 3 3 Explain why ArOR ethers are cleaved to give RI and ArOH rather than Arl and ROH.

Q.34 Explain the mechanism of following:

(iii)

(iv)

R ' R

(v)

0-CH7-CH=CHR CH=CH-CH3

OH CH2-CH=CHR CH=C-CH3

Me

0 35 Outline a synthesis of each alcohol from the indicated starting materials: (a) Isopropyl alcohol from a hydrocarbon (b) n-butyl alcohol from acetylene (c) allyl alcohol from propane, and (d) t-butyl alcohol from t-butyl chloride

Q.36 What product is expected from the reaction of (f O with (a) LiAlH4 and (b) H /^Pt

Q.37 Give the product of the reaction of PhjCHC^OH with HBr and explain its formation.

Q.38 Give the product and write a mechanism for the acid dehydration of cyclobutylcarbinol.

Q.39 C2H5OH PC'5 > (A) - KCN > (B) - ->(C) ->(D) (E)

Q.40 CH3CH2CH20H (A) ->(B) + (C)


EXERCISE-III Q. 1 Compound (A) gives Lucas test within 5 minutes. 6g (A) when reacts with Na, 1120 mL of H2 is

generated at STP. fA) having one oxygen per molecule. What is the structural formula of (A)? Compound (A) when treated with PBr3 gives (B) which when treated with benzene in presence of anhydrous A1C13 gives (C). What are (B) and (C)?

Q.2 An open chain compound (A) C5HgO is optically active. When (A) is hydrogenated in presence of Pd as catalyst, it absorbs two moles of F^ per mole of (A) to produce compound (B) C5H120 which is optically inactive. However when (A) is warmed with dilute E^SC^ in presence of HgS04 it gives compound C(C5H10O2) which is still optically active. C responds to iodoform test. What are the structures of A to C?

Q .3 An organic compound (A) C10H12O gives red colour when treated with cerric ammonium nitrate & also decolourises Br2 in CC14 to give B (C10H12OBr2). A can show both geometrical & optical isomerism. A on treatment with L, & NaOH gives iodoform & an acid (C) after acidification. Give the structures of A to C & also the stereoisomers of A.

Q. 4 A(C7H]4) decolorises Br2 in CC14 reacts with Hg(OAc)2. THF-NaBH4 to form B (resolvable compound)

A C < K M n Q ^ - 3 hexanol 2 . Z n / H 2 0

l .B2H6 .THF v D (isomer of A) 2 H 0 / 0 H - > E (chiral) YMaD^ > F (chiral carboxylic acid)

D (isomer of A) 1 3 > G < KMn04/alkaline 2 m e t h y l 3 pentanol 2 . Z n / H 2 0

Find out A to G.

(v)

the given starting materials and any necessary organic or inorganic reagents.

CH2OCH3 from - COCH, (ii) frombromobenzene and cyclohexanol

Q. 5 Suggest short, efficient reaction sequence suitable for preparing each of the following compounds from

(0

(iii) C6H5CH2CHCH3 frombromobenzene and isopropyl alcohol I OH

(iv) CfiH5CH2CH2CH2OCH2CH3 from benzyl alcohol and ethanol.

from 1,3-cyclohexadiene and ethanol

(vi) C6H5CHCH2SCH2CH3 from styrene and ethanol I

OH

Q.6 A compound (X) reacts with thionyl chloride to give a compound (Y). (Y) reacts with Mg to form a Grignard reagent, which is treated with acetone and the product is hydrolysed to give 2-methyl-2-butanol. What are structural formulae of (X) and (Y)?


Q. 7 The compound (D) reacts with BH3- Tetrahydrofuran and then alkaline H202 to give chiral (E). Oxidation of (E) with KMn04 (acidified) gives a chiral carboxylic acid (F). Ozonolysis of 'D' gives after reduction with Zn the same compound (G), which is obtained by oxidation of 2-methyl-3 -pentanol with acidified KMn04. Identify (D), (E), (F) and (G).

Q. 8 An organic compound (A) contains 60.12% Carbon, 13.13% Hydrogen and has vapour density 3 0. On oxidation it gives (B) C3H60 which on further oxidation by NaOH +12 produces a salt of the acid (C) C2H402. When (B) is treated with hydroxyl amine, a compound of molecular formula C3H7NO (D) is formed. What are (A), (B),(C) and (D)?

Q. 9 Compound (A) C4H|0O reacts rapidly with metallic sodium, but undergos almost no reaction with Lucas reagent. When (A) is treated with hot concentrated sulphuric acid, a new compound (B) C4H8 is formed. If C4Hg is hydrated with sulphuric acid a new compound (C) C4H9OH is formed, which is almost inert to metallic sodium but reacts rapidly with Lucas reagent. What are (A), (B) and (C)?

Q. 10 A compound (X) containing C, H and 0 is unreactive towards sodium. It does not add bromine. It does also not react with Schiffs reagent. On refluxing with an excess of HI, (X) gives only (Y). (Y) on hydrolysis gives (Z) which can be converted to (Y) by the action of P +12, Compound (Z) on oxidation gives an acid of equivalent weight 60. What are (X), (Y) and (Z)?

Q. 11 A compound (A) C;Hlf)n^ yields on acetylation (B) of formula C12H1808. How many hydroxyl groups are present in compound? A l s o write structures of (A) and (B).

Q. 12 An optically active alcohol (A) (C6H10G) absorbs two moles of hydrogen per mole of (A) upon catalytic hydrogenation and gives a product (B). The compound (B) is resistant to oxidation by Cr03 and does not show any optical activity. Deduce the structures of (A) and (B).

Q.13 An unsaturated hydrocarbon (A) on hydration gave alcohol (B). Oxidation of (B) gave a ketone (C). When the hydrocarbon (A) was submitted to ozonolysis it gave formaldehyde and acetaldehyde. What one formula would you assign to A, B and C? Give the reactions involved.

Q. 14 Compound (A) reacts with sodium to liberate H2 forming a compound (B). When (A) is treated with HC1 + ZnCl2, an immediate reaction takes place liberating (C). When (A) is heated with H2S04, (D) is formed. Ozonolysis of (D) gives a three carbon ketone and another isomeric compound. What are (A), (B), (C) and (D) ?

Q.15 An organic compound (A) (C4H]0O) reacts with HI giving a compound (B) (C4Hgl) which on reduction gives a normat hydrocarbon having four carbon atoms. On oxidation A gives compound (C) (C4HgO) and then an acid (D) (C4H802). Deduce th structures of, B, C and D giving reasons.

Q. 16 An organic compound (A) gives hydrogen on reacting with sodium. It also gives iodoform test and forms an aldehyde of molecular formula (B) (C2H40) on oxidation. Name the compound (A) and (B).

Q.17 An organic compound (X) on analysis gives 24.24% C, 4.04%H. Further sodium extract of 1.0 g of (X) gives 2.90 g of AgCl with acidified AgNO, solution. The compound (X) may be represented by two isomeric structures (Y) and (Z). (Y) on treatment with aqueous KOH solution gives a dihydroxy compound, while (Z) on similar treatment gives ethanal. Find out (X), (Y) and (Z).


Q.18 Compound (X) (C5HgO) does not react appreciably with Lucas reagent at room temperature but gives a precipitate with ammonical silver nitrate. With excess ofMeMgBr, 0.42 g of (X) gives 224 ml CH4 at STP. Treatment of (X) with H2 in presence of Pt catalyst followed by boiling with excess HI gives n-pentane. Suggest structure for (X) and write the equations involved.

Q. 19 An alcohol (A) when heated with concentrated H S^C^ gives an alkene (B). When (B) is bubbled through bromine water and the product obtained is dehydrohalogenated with excess of sodamide, a new compound (C) is obtained. The compound (C) give (D) when treated with dilute H^SC^ in presence of HgS04. (D) can also be obtained either by oxidising (A) with KMn04 or from acetic acid through its calcium salt. Identify (A), (B), (C) and (D).

Q. 20 Compound (A) contains only carbon and hydrogen. It decolorizes bromine in CC14 solution and reacts slowly with concentrated HjSO^ Compound (A) reacts withHBr to form (B). (B) reacts with NaOH to form (C). (C) on oxidation gave hexanone-3. Write structures of (A), (B) and (C).

Q. 21 A hydrocarbon (A) (molecular formula C5HJ 0) yield 2-methylbutane on catalytic hydrogenation. (A) adds HBr in accordance with Markownikoff s rule to form a compound (B), which on reaction with silver hydroxide forms an alcohol (C) C5H120. Alcohol (C) on oxidation gives a ketone (D). Deduce (A) to (D) and give the reactions involved.

Q.22 (A) ( b ) ._JiM_> (c) ( ^ - W k ^ A ) ' 250C V > (ii)AgOH ' 150C V ' ( i i ) H 2 0 2 , 0 H - '

In the above reactions scheme (A) and (C) are isomers. (B) has a formula of C5H10. (C) Can also be obtained from the product of the reactions of CH3CH2MgBr and (CH3)2CO. Give structures of (A), (B)and(C).


EXERCISE-IV (A)

Q.l l O j + C02 > x - J*" -* T c n n H ; The product X in the reaction is:

[REE 1990]

w ( O J are: [JEE 1995] (A) C6H5OH + CH3I (B) C6H5I + CH3OH (C) C6H5CH3 + HOI (D) C6H6 + CH3OI

Q 5 The order of reactivity of the following alcohols: [JEE 1997] CH3 CH3

o n Y F I Ph OH CH3 / V C H 3

U) (II) 0 H OH (IV)

an) towards conc. HClis: (A) 1 > II > III > IV (B) I > III > II > IV (C) IV > III > II > 1 (D) IV > II > III > I

Q.6 .Among the following compounds, the strongest acid is: [JEE 1998] (A) HC=CH (B)C6H6 (C) C2H6 (D) CH,OH

Q.7 Benzenediazonium cliloride on reaction with phenol in weakly basic medium gives: * [JEE 1998] (A) Diphenyl ether (B) p-hydrooxyazobenzene (C) Chlorobenzene (D) Benzene

Q. 8 Which one of the following will most readily be dehydrated in acidic condition: [JEE 2000] O O

0 OH OH A A A cb) A X Y X

/ V \ / V \ 0 H 0 H

Q.9 1 -propanol & 2-propanol can be best distinguished by: [JEE2001] (A) Oxidation with alkaline KMn04 followed by reaction with Fehling solution (B) Oxidation with acedic dichromate followed by reaction with Fehling solution (C) Oxidation by heating with copper followed by reaction with Fehling solution (D) Oxidation with concentrated H2S04 followed by reaction with Fehling


Q. 10 Identify the correct order ofboiling point of the following compounds: CH3CH2CH2CH2OH CH3CH2CH2CHO CH3CH2CH2COOH

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

[JEE 2002]

Q.ll < O ^ O H + C2H5I ^ O Na + (excess )

(A)

;OH(anhydrous)

< 0 } - O C 2 H 5 < B ) @ - I (C)C6H5OC6H5 (D)C2H5OC2H5

[JEE 2003]

Q. 12 Reaction of entainomerically pure acid with 1 chiral carbon and racemic alcohol with 1 chiral carbon gives an ester which is: (A) Meso (C) Racemic mixture

(B) Optically active mixture (D) Enantionmerically pure

[JEE 2003]

Q.13 On acid catalysed hydration, 2-phenyl propene gives: (A) 3-phenyl-2-propanol (B) 2-phenyl-1 -propanol (C) 1 -phenyl-3 -propanol (D) 2-phenyl-2-propanol

[JEE 2004]

Q. 14 Phenyl magnesium bromide reacting with t-Butyl alcohol gives

CH,

[JEE 2005]

(A) Ph - OH (B) P h - H

/ C H 3 (C) Ph-0-C~C:H3 ( D ) PI1-C-CH3

CH \ CH,

Q.15 Which is the best reagent to convert cyclohexanol into cyclohexene. [JEE 2005] (A) conc. HC1 (B)conc.HBr (C) conc. H 3P0 4 (D)HCl + ZnCl2

CH3H CH3

Q. 16 Compound (X) C H 3 0 - < ^ O y > is reacted with aqueous acetone it gives

H CI CH3

following products:

C H 3 H CH3 C H 3 H CH3

C H 3 O - < O ) - < Q > N O 2 ( K ) C H 3 O - ^ > - ^ ( O ) - N 0 2 ( L )

H OHCH 3 OH H CH3

C H 3 H CH3

CH3O-

(A) K, L

-N02(M)

H CH3 OH

(B) K, M (C) L only (D) M only [JEE 2005]

^Bansal Classes Alcohols & Ethers [25]

Q 17 + CI - CH2CH2 - CH3 ^ ^ > Q + Phenol [JEE 2006]

The major products P and Q are

( A ) j ^ a n d C H 3 C H 2 C H O (B) j ^ j and CH3COCH3

( C ) f S a n d C H 3 C O C H 3 (D) f S and CH3CH2CHO

| I i 1 I

j

i i i

I ] ! i

feBansal Classes Alcohols & Ethers

I

EXER CISE-IV (B) OA When t-butanol and n-butanol are separately treated with a few drops of dilute KMn04 in one case

only, purple colour disappears and a brown precipitate is formed. Which of the two alcohols gives the above reaction and what is the brown precipitate? [JEE 1994]

(XZ 3,3-Dimethylbutan-2-ol losses a molecule of water in the presence of a concentrated sulphuric acid to ^ give tetramethyl ethylene as a major product. Suggest a suitable mechanism. [JEE 1996]

Q.3 A compound D (CgH10O) upon treatment with alkaline solution ofiodine gives a yellow precipitate. The filtrate on acidification gives a white solid (E) (C7H602). Write the structures of (D) and (E) and explain the formation of (E). [JEE 1996]

Q. 4 Which of the following is the correct method for synthesising methyl-t-butyl ether and why? (i) (CH3)3CBr + NaOMe > (ii) CH3Br + tert-BuONa > [JEE 1997]

O = C-OH HOCH2 Q.5 I + I [JEE 1997]

O = C-OH HOCH2

Q j / Discuss why o-hydroxy benzaldehyde is a liquid at room temperature while p-hydroxy benzaldehyde is a high melting solid? [JEE 1999]

Q.7 White the structures of the product A&B [JEE 2000]

CH - C - 0 1 8 C H h3 . n 3 ^ u ^2n5 2 > A+B

O Q.8 Cyclobutyl bromide on treatment with magnesium in dry ether forms an organometallic A. The

organometallic reacts with ethanal to give an alcohol B after mild acidification. Prolonged treatment of alcohol B with an equivalent amount ofHBr gives 1 -bromo-1 -methylcyclopentane (C). Write the structures of A, Band explain how C is obtained from B. [JEE 2001]

Q. 9 Identify X, Y and Z in the following synthetic scheme and write their structure. Explain the formation of labelled formaldehyde (H2C*0) as one of the products when compound Z is treated with HBr and subsequently ozonolysed. Mark the C* carbon in the entire scheme. [JEE 2001]

BaC*03 + H2S04 > X (gas) [C* denotes C14]

CH2 - CH - Br ^M* /ether >y LlAm-* >Z ( i i )X , ( i i i )H ,0 +

Q.10 Mention two esters produced when a racemic mixture of 2-phenyl propanoic acid is treated with (+) 2-butanol. What is the stereochemical relationship between these esters? [JEE 2003]

Q. 11 An organic compound P(C5H10O) Reacts 1015 times faster then ethylene with dil.H2S04 to give two products Q and R. Both Q and R give positive iodoform test. Identify P, Q and R and also give reason for very high reactivity of P. [JEE 2004]

Q. 12 (X) C5H!3N NaNo 2 ,HCi > ( Y ) (Tertiary alcohol + other products) -N2

(Optically active) Find X and Y. Is Y optically active? Write the intermediate steps. [JEE 2005]


ANSWER KEY EXER CISE-I(A)

Q.I- B Q.2 A Q 3 C Q.4 B Q.5 B Q.6 D Q.7 D Q.8 C Q.9 D Q.10 c Q.ll A Q. 12 C Q.13 A Q.14 C Q.15 B Q. 16 A Q.17 B Q.18 C Q. 19 D Q.20 C Q.21 D Q.22 A Q.23 B Q.24 D Q.25 A Q.26 B Q.27 A Q.28 B Q.29 A Q.30 A Q.31 C Q.32 C Q.33 D Q.34 D Q.35 D Q.36 B Q.37 A Q.38 B Q.39 A Q.40 A Q.41 C Q.42 A Q.43 A Q.44 D Q.45 A Q.46 C Q.47 C Q.48 C Q.49 C Q.50 A

EXER CISE-I (B)

Q.l A,C,D Q.2 C Q.3 A,C Q.4 B Q.5 A, B,D Q.6 A,B Q.7 A,B,C Q.8 A,B,C Q.9 A,D Q.10 A,B,D Q.ll A,C Q.12 A,B,C Q.13 A,B,C,D Q.14 AB,C,D Q.15 A,B,C Q.16 A,C,D Q.17 A,B,C Q.18 A,B Q.19 Q.20 A Q.21 A,C Q.22 C,D Q.23 A,B,C,D Q.24 A,B,C,D Q.25 A,B Q.26 (A) P, Q, S; (B) R,S; (C) P; (D) S Q.27 (A) Q,R,T, (B) R, (C) S, (D) P Q.28 (A) Q,R,S (B) S (C) Q (D) P Q.29 (A) R, S; (B) R; (C) Q; (D) P Q.30 A,B,D

EXER CISE-II

O Ii

(c) Ph - C - CH2 - CH2 - CH

OCH3

In basic medium Me2 C - CH2

O

Q.5 (A) C H 3 - C - O - C - C - C - C , (B) C H r C H 2 O H , (C) C H 3 - C H 2 - C H 2 - C H 2 - O H ,

O OH O II i II

(D) C H , - 0 - H , ( E ) CH3- CH -CH - C H O (F) CH - C H = C H - C - H

Q 2 (a) Et-CH=CH-CHO (b) Ph-CHO

o

(d) No reaction (e)

OCH3

Q. 4 In acidic medium Me2 - C - CH2 and

OH

faBansal Classes Alcohols & Ethers [28]

Q . 9 ( A ) = C H 2 - O H

I CH 2-OH

Q.10 a > b > d > c Q. 12 (a) Lucas reagent (b) Iodoform (c) PBr3 & AgN03 (d)Na Q. 13 (a) 1-hexanol reduces organ red Cr03 to greenCr3^ while 1-chlorohexane gives white ppt. ofAgCl on

warming with ethanolicAgN03. \ (b) n-Butanol gives a positive test with Cr03 in acid and evolves H2 with sodium: while dry ethyl etheris

negative to both tests (c) Unlike n-pentane, diethyl ether is basic and dissolves in conc. f^SC^

(C2H5)20 + H ^ > (C2H5)2OH++ HSO" Q.14 (a) Ethyl alcohol first reacts with sulphuric acid to form ethyl hydrogen sulphate which readily lo ses a

molecule of sulphuric acid when heated with concentrated sulphuric acid at 170C to form ethylene, (b) When sodium chloride is dissolved in water it reduces the polarity of water the space between water

molecuules are occupied by sodium and chloride ions with the result the solubilty of the organic compound is reduced.

Q.15 CH3I, CH3-0-CH3, CH3I Q . 1 6 C H 3 O H p + 1 2 ) C H , I KCN ? C H 3 C N reduction ) C H 3 C H 2 N H 2 HONO ?

Methanol

CH3CH2OH _JO)_> CH3CQOH Ethylamine Ethano!

C H 3 O H ( KOH(aq.) CHGCL ( C12 ' C H ,

Q.17 (a) In order of increasing boiling points: (I) Propane < Ethanol

Q.18 (i) MeOEt + HI ^ lMe^O-Et > Mel + EtOH > EtI The reaction is SN2 the smaller group forms the iodide (steric effect) & stops at the first stage in the cold. When heated, the reaction proceeds to the second stage.

(ii) Et20 N o reaction as there is no active H in the compound.

H

(iii) Me, = CH, h2s4-h2 > M e C+ Me3CH > Me3C-0-CMe3 "H+ >Me3C-0-CMe3 W pressure 3 P r e s s u r e + 3 3

Q. 19 (i) n - C3H7C02H > n - C4H9OH orB 2 H 6

/OMgl (ii) Me2CO + EtMgl >M2C MeXCOH)Et

IMgO x / M e (iii) EtC02Et + 2MeMgI > C "2 ) EtCMe2OH

E t X X M e

(iv) C H C 0 2 E t LiA1H4 > ^ ^ C H C ^ O H Mn2 > ( ^ ^ C H C H O

Q. 20 The +I.E. of three methyl groups on central C-atom of tert-butyl alcohol makes is partially negative with the result that it pushes the electron pair of -OH bond towards H-atom and thus H-atom is not replaced easily.

CH3 h ^ - 5 + 0 I ' -6 +8

CH3"^ C H CH3-CH2-CH2-> C 0-- H t I CH3 H

(less partial +ve charge) (more partial +ve charge) Q.21 Oxygen atom in diethyl ether molecule has two lone pair of electrons available for co-ordination. Therefore

ethers behave as Lewis base forming oxonium salts.

r ^ > 0 : + HC1 > f^OH+Cl- (dialkyl oxonium chloride)

Q.22 Proof spirit is a technical term representing 57.1 % by volume ethanol-water mixture for the purpose of tax lavied on its production. The percentage represents the weakest possible percentage which allows the gun powder to catch fire.

Q. 23 Sodium metal reacts with ethanol to form sodium ethoxide ion because of active H atom in ethanol. Ether do not have such active H and thus can be dried by sodium

1 C2H5OH + Na > C2H5ONa + - H 2

Q.24 Due to the formation of explosive peroxide by oxidation.

Q.25 Addition of methyl alcohol or naphtha or pyridine is made into ethyl alcohol to make sure that it will not be used for bevarage purposes. This process is known as denaturation of alcohol.

^Bansal Classes Alcohols & Ethers [30J

Q.26 C2H5OH, C2H5HS04, C2H5- 0-C2H5

Q.27 Ethanol being very weak Lewis base and thus reacts with stronger acid HI

(iii) MePhS020CH2CH2CH3 Q.28 (i) CH3CH2COOH (ii) CH3COOCH2CH2CH3 O

(iv) PhCOOH + PhCOOCH2CH2CH3 (v) -CH2CH2CH3

Q.29 ( A ) \ ^ J ( B ) ^

(D) CH2 = CH-CH2(C1) - CH3

(F) CH3-CH(C1) CH2CH2CH2OH

CH?OH

OH (c)CJ (E) CH3CH(C1)CH2CH2CH0

Q.30 ( a ) [ O l r 2 (b)

Br NFL OMe

CH2Ph Me' t)H OH

(d) H3C-CH2-CH2-CH2-S-CH2-(CH2)16-CH3

(c)Ph-CH(Cl)-CH2OH

Q.31 (A) CH2=CH-CH2-CH2OH Br

(C) 0 Q (B) Bi-CH2CH(Br)CH2CH2OH

CH2OH

CI| H

M e

( F ) Me-CH-CH2 O

Q. 3 2 (a) m-nitrophenyl acetate (better leaving group)(b) p-nitrophenyl acetate (better leaving group) (c) sodium salt of phenol (better nucleophile) (d) sodium salt of phenol (better nucleophile) (e) Phenol (more activated aromatic ring.)

Q.33 Sn2 attack on a carbon of a benzene ring does not occur nor does the high energy C6H5+ form by an SN1 reaction. Hence ARL cannot be a product even in an excess of conc. HI

Q.36 (a) (b) 0 < H

Ph I

Q 37 Ph - C - CH3 I

Br fe Bansal Classes Alcohols & Ethers [13]

^ / v r Q 3 8 V-Cli-,OH " > - H 2 Q H Q.39 (A) C2H5C1; (B) C2HSCN; (C) C2H5COOH; (D) C2H5COONH4

(E) C2H5CONH2 Q.40 (A)C3H7Br; (B) CH3CH=CH, (C) CH3CHBrCH3 (D) CH3CHNH2CH3

EXER CISE-III

OH

Q.l A: CH3 - CH - CPI3

H H H O ! I I I!

Q.2 (A) C - C - C - C = C (B) C - C - C - C - C (C) C - C - C - C - C

OH OH OH OH Br OH O

Q 3 (A) Ph - CH = CH - CH - CH3, (B) Ph - CH - CH - CH - CH3 , (C) P h - C H = C H - C - O - H

Br

CH2 CH3 0 1! I II

Q4 (A) C - C - C - C - C - C , (B) C H 3 - C H 2 - C - C H 2 - C H 2 - C H 3 , ( C ) C - C - C - C - C - C

OH

CH2 CH3

(D) Et - CH - CH2 - CH = CH2, (E) Et - CH - CH2 - CH2 - OH, (F) Et - C H - C H 2 - C 0 2 H

CH3

CH, CH, C O C I II I .11 I

(D) CH3 - CH - CH - CH2 - CH3, (G) C - C - C - C - C , C - C - C - C - C -

OH

Q.6 C2H5OH C2H5C1 Ethyl alcohol Ethyl chloride

(X) (Y)

(!lBansal Classes Alcohols & Ethers [32]

Q.7 C H 3 - C H - C = CH2

CH3 (DJ CH3 C2H5

H

H

C H 3 - C H - C - C H 2 O H

CH3 C2H5 (E)

C H 3 - C H - C - C O O H CH, - CH - C = O

CH3 C2HJ (F)

Q.8 (CH3)2CHOH; CH3COCH3;

CH3 C2H5 (G)

CH3COOH; CHGCCHG

(A) (B) (C)

NOH

(D)

Q.9 (CH3)2CHCH20H; (A)

( C H ^ C - C H ^ (B)

(CH3)3COH (C)

Q.10 C2H5OC2H5 ; (X)

C2H5I; (Y)

C2H5OH (Z)

Q.l l Four OH groups are present in compound A. CH2OCOCH3

Q. 12

CH2CH CH CH2

OH OH OH OH (A)

C2H5

H X - C - C = CH

OH (A)

CHOCOCH,

CHOCOCH,

CH2OCOCH3 (B)

C2H5

CH3CCH2 CH3

OH n(B)

Q.13 CH3 H

V c 7 H / \ H

(A)

CH3 CH CH3

OH (B)

CH3 C CH3

o (C)


Q.14 CH3CH2CH2C(CH3)2 CH3CH2CH2C(CH3)2 CH3CH2CH2C(CH3)2

OH (A)

CH3CH2CH = C(CH3)2 (D)

Q.15 (A) CH3CH2CH2CH20H (C) CH3CH2CH2CHO

ONa (B)

CI (C)

(B) CH3CH2CH2CH21 (D) CH3CH2CH2COOH

Q. 16 (A) CH3CH20H (B)CH3CHO

Q. 17 (X)C2H4C12 (Y)C1CH2CH2C1 (Z)CH3CHC12

Q.18 CH2CH2CH2C = CH i OH (X)Pent 4 - y n - l - o l

CH, Q.19 (A) \ C H O H (B) CH3-CH=CH2 (C) CH.C.CH (D) CH3COCH3

C H /

Q 20 CH3-CH2-CH=CH-CH2-CH3 +1IBR > CH3 - CH2 - CH2 - CH - CH2 - CH3

(A)

Br

(B)

Q.21 (A) CH2=CH-CH(CH3)2

(C) C H 3 - C H C H ( C H 3 ) 2 I OH

CH3 - CH2 - CH2 - CH - CH2 - CH3

OH

(C)

(B) C H 3 - C H - H C ( C H 3 ) 2

Br

(D) CH3CO CH(CH3)2

OH

Q.22 ( A ) H O - C - C - C - C (B) C = C ' - C - C ( C ) C - C - C - C


EXERCISE-IV (A)

Q.l D Q.6 D Q.ll D Q.16 A

Q.2 B Q.3 D Q.7 B Q.8 A Q. 12 B Q.13 D

EXERCISE-IV (B)

Q.4 A Q.9 C Q.14 B

Q.5 C Q.10 B Q.15 C

Q.l n-butanol is oxidised by KMn04 and not t-butanol as the latter does not contain H atom attached to carbinol carbon atom.

CHjCHjCHjCHjOH + KMn04 -> CH,CH2CH2COOOK + Mn02 + KOH n-Butanol Brown

CH3

CH3-C - C H 3 +KMn0 4 > No reaction

OH

t-Butanol

H Me j |

Q.2 C H 3 - C C - C H 3 -

:OH Me

Me

C H 3 - C = C - C H 3 C H 3 - C C - C H 3 -H2 > C H 3 - C H - C - C H 3 1 1 Me

- H +

HIOH Me

Me

CH, - CH - C - CH, i | + J Me

1,2-methyl shift

(E) CfiH,COOH Q.3 (D) Ph - CH - CH3

OH

Q. 4 The ether formation involves nucleophilic substitution of alkoxide ion for halide ion.

R'0~+R-X R'0~+R a Slow ->R' 0 R X - ^ R ' - O - R + X-3 alkyl halide can also involve elimination ofHX to give alkene in the presence of a base. So, it is better to start with 3 alkoxide and 1 alkyl halide, i.e., equation (b)

Q.5 X Q.6 Due to intermolecular H-Bonding Q.7 A = C H 3 - C - 0 H , B = C2H5018H

O


Br

Q.8 Mg MgBr BrMgOCHMe

MeCHO . HOCHMe

Br Me

H,0

(A)

Mechanism

HOCHMe

(B) (C)

H-,0 CHMe CHMe

^ y / M e

2carbonium

Br Me

3 carbonium

Br~

Q.9 X : CO, ; Y : C H , = C H - C O O H ; Z : CH, = CHCH-OH ; C H , 0 RCT+RQC

Ph H

Q.10 CH3 - C - COOH + CH3 - C - COOH

2 2

H

(+)CH3CH2-C-OH

CH3 conc. H,SOa , A

H

(recemic mixture)

Ph H

Ph

H H

CH, - C - C - O - C - CH2CH3 + CH3 - C - C - O - C - CH2CH3

H O CH3 Ph O CH,

during esterification reaction only - COOH and - OH participates. There is no effect on structure of configuration of carbon adjacent of these groups. So when () acid reacts with pure (+) alcohol two esters are produced whine are diastereoisomers of each other.

CH,

Q.l l P: C H 3 - C H 2 - 0 - C - C H 3

Q : CH3CH2OH

R: C H 3 - C - C H 3

O

when ethylene reacts with dil. H2S04CH3CH2 is produced during rate determining step, whereas P gives resonance stabilized intermediate.

CH,

C H 3 - C H 2 - O - C - C H 3

CH,

C H 3 ~ C H 2 - O = C ~ C H 3

due to extra stability of intermediate the rate of reaction is very fast


| BANSALCLASSES TARGET IIT JEE 2007

ORGANIC CHEMISTRY x n i ( X Y Z )

AROMATIC COMPOUNDS

CONTENTS EXERCISE-I EXERCISE - II EXRECISE-III

EXRECISE-IV(A) EXRECISE-IV(B)

ANSWER KEY

EXERCISE-I

Q. 1 How many n electron are there in the following species:

(A) 2 (B) 4 (C) 6 (D)8

Q.2 Number of n electrons present in naphthalene is: (A) 2 (B) 4 (C) 10 (D) 14

Q. 3 Which of the following is not the property of benzene: (A) Characteristic smell (B) Inflammable (C) Unsaturation (D) Colourless

Q. 4 Benzene undergoes substitution reaction more easily than addition because: (A) It has a cyclic structure (B) It has three double bonds (C) It has six hydrogen atoms (D) Of resonance

Q.5 The order of reactivity of following compounds: (I) III > IV (B) IV > III > II > I (C) II > I > III > IV (D) III > II > I > IV

Q. 6 Which one of the following is the most basic compound: (A)C6H5-NH2 (B)C6H5-NHCH3 (C) C6H5-N(CH3)2 (D) C6H5N(C2H5)2

Q.7 Find odd compound out: (A) Lindane (B)Gammexane (C) 666 (D)HCB

Q. 8 Which of the following reagents and conditions convert benzene to chloro-benzene: (A) Cl2, sunlight, heat (B) HC1, heat (C) HC1, sunlight, heat (D) Cl2, A1C13, cold

Q. 9 Which order is correct for the decreasing reactivity to ring monobromination of the following compounds: (I)C6H5CH3 (II) C6H5COOH (III)C6H6 (IV) C6H5NO2 (A) I > II > III > IV (B) I > III > II > IV (C) II > III > IV > I (D) III > I > II > IV

Q.10 Benzene on treatment with a mixture of conc. HN03 and conc.H2S04 at 90C gives: (A) Nitrobenzene (B) m-Dinitrobenzene (C) p-Dinitrobenzene (D) o-Dinitrobenzene

Q.ll Which of the following structures correspond to the product expected, when excess of C6H6 reacts with CH2C12 in presence of anhydrous A1C13:

( B ) Q - C H C L 2

1

to Bansal Classes Aromatic Compounds Page # 2

Q. 12 For preparing monoalky! benzene, acylation process is preferred than direct alkylation because (A) In alkylation, a poisonous gas is evolved (B) In alkylation. large amount ofheat is evolved (C ) In alkylation, pollyalkylated product is formed (D) Alkylation is very costly

Q.13 Benzene reacts with n-propyl chloride in the presence of anhydrous A1CL to give predominantly: (A) n-Propylbenzene (B) Isopropylbenzene (C) 3-Propyl-1 -chlorobenzene (D) No reaction

Q.14 In the sulphonation. acetylation and formylation of benzene the group of effective electrophiles would be:

(A) SO:,CH3 = O.HCO (B) SO3.CH3 - C = O-HCO

(C) SOv CH3CHO, CO + HC1 (D) HS03 , CH3CO, HCO

(Q.15) Number of benzene derivatives of C7H7C1 is: ^ ^ (A) 2 (B)4 (C) 5 (D)6

Q.l 6 The number of benzene derivatives of the formula C?HgO is: (A) 2 (B) 3 (C)4 (D)5

Q.17 Ethyl benzene + Cl7 ( m a i n ) compound is: (A) o-& p-chloroethylbenzene (B) 1 -Chloroethylbenzene (C) 2-Chloroethy 1 benzene (D) m-Chloroethylbenzene

Q.18 Chlorinaton of toluene in die presence oflight and heat followed by treatment with aqueous NaOI I gives: (A) o-Cresol (B)p-Cresol (C) 2,4-Dihydroxytoluene (D) Benzyl alcohol

Q.l 9 p-Nitrotoluene on further nitration gives:

CI-I3 CH3 CH9OM

r r N 2 r S fr ^ ( A ) 1 ^ ( C ) V ^ (D) NO 2 NO-, N O , " N O , OoN

Q.20 In the reaction of p-chlorotoluene with KNH2 in liquid NH,, the major product is: (A) o-Toluidine (B)m-Toluidine (C) p-Toluidine (D) p-Chloroanilinc

Q.21 Maj or product of this reaction will be: CH,

A I C I 3 . A

(A) o-xylene (B) p-xylcne (C) both (D) m-xylene


Q.22 C6H5CH3 C r 0 ^ >A >B The functional group present in B and name of the reaction would be (A) -CHO, Gattermann aldehyde synthesis (B) -CHO, Etard reaction (C) -COCH3, Friedel Crafts reaction (D) -CHO, Oxo reaction

Q.23 Which chloroderivative of benzene among the following would undergo-hydrolysis most readily with aq.NaOH to furnish the corresponding hydroxy derivative.

.N02 ( A ) 0 2 N - / o V - C 1 ( B ) 0 2 N - < O ) - C 1

( N O 2

(C) Me2N CI ( D ) ( o y C \

Q.24 . The order of relative reactivity of the given halides towards SN2 reaction is: (A) PhCH2Cl > PhCHClCH3 > PhCCl(CH3)2 (B) PhCH2Cl < PhCHCl(CH3) < PhCCl(CH3)2 (C)PhCHCl(CH3)>PhCH2Cl>PhCCl(CH3)2 . (D) PhCHCl(CH3)>PhCCl(CH3)2 > PhCH2Cl

Q.25 An aromatic compound A' C7H6C12, gives AgCl on bonding with alcoholic AgN03 solution, and yields C?H70C1 on treatment with sodium hydroxide. 'A' on oxidation gives a mono chlorobenzoic acid which affords only one mononitro derivative. The compound A is:

CH,C1 CH2CI CH2CI

(A)^ (B)^ C1 (C)[|rC1 (D)(OlCH2CI

Q.26 Which ofthe following reactions will not take place:

(A) ArN + CuBr > ArBr (B) ArNf + PhOH > Ar ^ O V 0 H

(C) ArN +H3H02 H2O > A r H (D ) A r N + I - > A r i

Q.27 Which of the following substituted benzene derivatives would furnish three isomers in significant amount when one more substituent is introduced:

CI Br

fol wlSC (ofBr fo


Q.28 Which of the following reaction does not take place?

Br

(A) CH3 OCH3 k n h2 > (B) - ) - CI + aq. KOH -liq.NH,

C1 300C (C) H - CI + ale. KOH > (D) If j + NaOH 300 L > V ' 1 1' J 200 atm

Q.29 m-Bromotoluene is prepared by: (A) Bromination of toluene (B) Friedel Craft's reaction of bromobenzene with CH3C1 (C) Bromination of nitrobenzene and subsequent replacement of -N0 2 group with methyl group (D) Bromination of aceto-p-toluidine followed by hydrolysis and deamination

Q.30 Benzyne intermediate is not observed in: OCH3 CI CI +

(A) ( o f (B) ( O [ )

OCH3 NaNH Q.31 O 2~~> A, maj or product A and reaction R are:

Br

OCH,

(A) I O I , elimination addition (B) j 2, elimination addition l2

OCH, OCH,

(C) O I , cine substitution (D) O .additionelimination

Q.32 Chloral+ {Q^>-C1 Conc.H2SQ4 ) product. The product is:

(A) Lindane (B) DDT (C)Tefflon (D) Ethaneperchlorate

Q.3 3 Which of the following group is divalent: (A) Benzoyl (B) Benzyl (C)Benzal (D)p-Tolyl

Q.34 C6H6 + A a'C3 > C6H.CONH2 A in the above reaction is: (A) NH2CONH, (B) C1C0NH2 (C) CH3CONH2 (D)CH2(C1)C0NH2

Q. 3 5 When benzene is heated with acetic anhydride in the presence of anhydrous aluminium chloride at 80C, the product formed is: (A) Benzoic acid (B) Benzophenone (C)Acetophenone (D) Ethyl phenyl ketone


Q.36 CJL CH3C0C1 6 6 AlClj HCl

The end product in the above sequence is: (A) Toluene (B) Ethyl benzene (C) Both the above (D)None

Q.37 The species responsible for nitration and sulphonationby nitric acid conc. H2S04 and firming H2S04 are:

(A) N02 and S03 (B) NO+ and S03 (C) NO+ and S02 (D) N02 and S02

Q. 3 8 Which of the following reactions is not an example of electrophilic substitution: (A) C6H6 + +N02 C6H5N02 + H+ (B) CfiH5 + CH3C1 A1C13 > C6H5- CH3 + HCl

OH

(C)C6H6 + Cl2 uv l igh t > C6H6C16 (D)C6H5OH + CO + HCl > K > )

Q.39 { ( J ) + CH2CH2CH2C1 A'C'3 > hydrocarbon (X) major product X is:

CH,

(A) < 0 ^ CH2CH-CH3 (B) < O y C ~ C H | CH

CH, I

(C) CH2CH2CH2CH3 . (D) None is correct

Q.40 Reaction ofS03 is easier in: (A) Benzene (B) Toluene (C) Nitrobenzene (D) chlorobenzene

Q .41 If the mixture of the following four aromatic compounds on oxidation by strong oxidising agent gives: C H 3 C 2 H s C H 2 O H C H O

(A) Mixture of C6H5CH2OH + C6H5COOH (B) Mixture of C6H5CHO + C6H5COOH (C) Only C6H5COOH (D) None of the above

Q.42 Methyl group attached to benzene can be oxidised to carboxyl group by reacting with: (A)Fe20, (B)AgN03 (C)KMn04 (D) Cr03

C H = C H 2

Q.43 ( O ) ^ > B

Compound A and B respectively are: (A) o-Bromostyrene, benzoic acid (B) p-Bromostyrene, benzaldehyde (C)m-Bromostyrene, benzaldehyde (D) Styrene dibromide, benzoic acid

Q.44 Which of the following is the strongest o,p-directing group? (A) OH (B) CI (C) Br (D) C6H5

Q .45 The reaction of benzene with CO and HCl in the presence of anhydrous A1C1, gives: (A) Chlorobenzene (B) Toluene (C) Benzyl chloride (D) Benzaldehyde


Q.46 The number of benzyl ic hydrogen atoms in ethylbenzene is: (A) 3 (B)5 (C)2

ci (D)7

Q . 4 7 "X" 2V iRp.n?:ofrichioride Hydrolysis ) Y X and Y respectively are: (A) Benzene, Benzaldehyde (B) Toluene, Benzaldehyde (C) Toluene, Benzoic acid (D) Benzene, Benzoic acid

Q. 4 8 Product obtained when benzoyl acetic acid is heated with soda-lime is:

(a) ( A ) . Which ofthe following can be isolated as the product ofthis reaction. ^ ^ high pressure

( A ) Q ( B ) 0 ( C ) 0 (

Q. 5 2 Which of the following is/are produced when a mixture of benzene vapour and oxygen is passed over V205 catalyst at 775 K? (A) Oxalic acid (B)Glyoxal (C) Fumaric acid

Q. 5 3 Which of the following is the least reactive in the case of bromination: (A) Phenol (B) Aniline (C) Nitrobenzene

Q. 54 No. of 7t electrons in O i s : (A) 2 (B)4 (C)5

Q. 5 5 Which of the following is not an aromatic compound:

(A) O (B) (C)

(D) Maleic anhydride

(D)Anisole

(D)6

Q. 5 6 Benzene on reaction with A' forms j Q)

' A ' and 'B' are:

(A) Zn(Hg) + conc. HCl, O

(C) "Cl,NaBH

which on reaction with 'B' forms I Q

Cl,LiAlH4

Cl,Zn(Hg) + conc. HCl


Q.57 In a reaction of C6H5Y, the major product (>60%) is m-isomer, so the group Y is: (A)-COOH (B)-Cl (C) -OH (D)-NH2

Q.5 8 Which of the following will undergo sulphonation at fastest rate ?

(A) (B) (Q

Q.59 Aniline under acidic medium, when chlorinated, produces: (A) o-chloro aniline (B)m-chloro aniline (C)p-chloro aniline (D) Mixture ofortho and para-chloro aniline

Q.60 Which of the following undergoes chlorination at fastest rate? OH NH, NHCH3 NMe,

(A) (B)| (C)

Q. 61 Which of the following is most reactive towards sulphonation? (A) m-Xylene (B)o-Xylene (C) Toluene

Q. 62 Which of the following undergoes sulphonation at fastest rate ? (A)C6H5NO2 (B) C6H5CH2NO2

(D) l J (D) p-Xylene

(C) C6H5CH2CH2N02 (D)|

Q.63 Which of the following undergoes nitration fast?

NH2 N(CH3)3 CH2-NMe3

(A) [| 1 ( B ) f | ^ l (C)|

CH2CH2NME3

(D)

Q. 64 When sulphonilic acid (p-H2NC6H4S03H) is treated with excess of bromine, the product is: (A) tribromo product (B) dibromo product (C) monobromo product (D)tetrebromo product

Q. 6 5 Ring nitration of dimethyl benzene results in the formation ofonly one nitro dimethyl benzene. The dimethyl benzene is:

(A)

GH3

a s .*>(% CH,

(O i (D) None of these

Q.66 If p-methoxy toluene is nitrated, the major product is: CH, CH, CH 2N0 2

NO,

(B) n o 2 ( C ) V ^ OCH3 OCH3 OCH3

Q.67 Ifmeta-nitroanilineis chlorinated, the maj or product is:

(A)

(A)^^ -N0 2 CI

NH, NH, NH,

(B) NO,

(C)

(D) No reaction

NH,

-NO, (D) O NO,


Q.68 An aromatic compound of molecular formula CgH4Br2 was nitrated when three isomers of formula C6H3Br2N02 were obtained. The original compound is: (A) o-dibromobenzene (B) m-dibromobenzene (C) p-dibromobenzene (D) None of these

Q. 69 Which of the following carbocations is expected to be most stable? CH,

(A) |l H ' Y

(B) |MJ H^Y

CH-,

n > ^r -6ll6 ^6U6 l6x6

( Q k C f i H f i = k C f i D , = k C , T f i

( B ) k C 6 H 6 < k C 6 D 6 < k C 6 T 6

( D ) k C f i H f i > ' k C f i D f i < k C , T f i

Q. 74 For the electrophilic substitution reaction involving sulphonation, which of the following sequence regarding the rate of reaction is true?

( A ) KCF IHF I > K C , D , > K C , T , ( B ) k C 6 H 6 < k C 6 D 6 < k C 6 T 6

( D ) k C f i H f i > k C f i D < k C , T f i

Q. 7 5 The order of relative reactivity of the given halides towards SN1 reaction is (A) benzylchloride > p-methoxybenzylchloride > p-nitrobenzylchloride (B) p-methoxybenzylchloride > benzylchloride > p-nitrobenzylchloride (C) p-methoxybenzylchloride > p-nitrobenzylchloride > benzylchloride (D) benzylchloride > p-nitrobenzylchloride > p-methoxybenzylchloride


EXERCISE -II

Q.l Which of the following will show aromatic character:

( a ) 0 0 (B>0 ( c ) 0 (D)l!) Q.2 Which aromatic compound is obtained when n-octane undergoes catalytic hydroforming:

(A) ethyl benzene (B)m-Xylene (C)o-Xylene (D)p-Xylene

Q,3 Benzoic acid may be prepared by the oxidation of: CH2CH3 CH2OH COCH3 - OH

(A)[o] (B)[o] ( O f o f < D ) (Oj

Q.4 In which of the following reaction t-butylbenzene is formed:

(A) Benzene + iso-butyl chloride, A1C13 (B) Benzene + (CH3)2C = CH2 Bp3'HF )

(C) Benzene + t-butyl alcohol hiso4 > (D) Benzene + (CH3)2 C= CH2 Alc'3 >

NaOH H , 0 Q.5 [OJ 395QC2 ' Product is:

(A)gf0H ( B ) @ t 0 H W.Jf ^loT0 1

Q.6 Which of the following reactions of benzene proves the presence of three carbon-carbon double bonds in it: (A) Formation of a triozonide -(B) Hydrogenation of benzene to cyclohexane (C) Formation of C6H6C16 by addition of chlorine (D) Formation of nitrobenzene on heating benzene with a mixture of concentrated nitric acid and sulphuric

acid

Q.7 Electrophile NO attacks the following in which cases NO will be at metaposition:

CCI3 N 0 2 NMe3 O e

^ ( 0 ) iQ(o)

Q. 8 Benzene is a resonance hybrid mainly of two Kekule structures. Hence: (A) Half of the molecules correspond to one structure, and half of the second structure (B) At low temperatures benzene can be separated into two structures (C) Two structures make equal contribution to resonance hybrid (D) An individual benzene molecule changes back and forth between two structures


Q. 9 The reaction of replacement of a hydrogen atom in benzene by alkyl group can be brought about with the following reagents : (A) Alkyl chloride and A1C1, (B)AlkeneandAlCl3 (C)Alkanol and alkali (D)Alkanol and acid

Q.10 Which of the following is /are fitting reaction: (A) C6H5I + 2Na + ICH3 C6H5- CH3 (B)C6H5I + 2Na + IC6H5 > C6H5 - C6H5 (C) CH3I + 2Na + ICH3 > CH, - CH3 (D) C6H5CH2-C1 + 2Na + C1CH2C6H5 -

Q.ll Which of the following statements is correct: (A) Bromination of toluene occurs faster than that of benzene (B) Nitration of toluene is faster than that of ethylbenzene (C) The bromonium ion is a good nucleophile (D) Effective nitrating agent is nitrate ion

Q. 12 Electrophilic substitution in cinnamic acid will take place at: (A) Ortho-position (B) Para-position (C) Meta-position (D) On side chain

Q.13 Which of the following gives Friedel Crafts reaction?

N H ,

(A) (B)

NO,

(Q (D)

Q.14 Which of the following can be used in Friedel Crafts reaction? CI

(A) (B)CH2=CH-C1 (C)CH,CH2C1 (D)CH2CH-CH2-C1

Q.15 The good method for converting benzene into propyl benzene is: (A) C6H6 + CH3CH2CH2C1 + Anhyd. A1C13 (B) C6H6 + CH3CH2COCI+Anhyd. A1C13 and then treatment with Zn/Hg/HCl (C) C6H6 + CH3CH2C0C1 + Anhyd. A1C13 and then treatment with H2 Ni (D)C6H6 + Anhyd. A1C13 + cyclopropane

Q.16 Which of the following will undergo nitration slow than benzene? N H , CI NHCOCH,

(D)

Q.17 Which of the following is ortho-para directing group? (A) CF, (B) CC1, (C) -CH=CH-COOH ( D ) - N = C

to Bansal Classes Aromatic Compounds Page #11

Q.18 Which of the following statements is true? (A) Ortho-and para-directing groups increase electron density at ortho-and para-positions (B) Meta-directing groups increase electron density at meta-position (C) Meta-directing groups decrease electron density at meta-position (D) Ortho-and para-directing groups decrease electron density at meta-position

Q. 19 Which of the following statements is/are not true? (A) All ortho-para directing groups activates the ring (B) All ortho-para directing groups except halogens activate the ring (C) All meta-directing groups have rc-bond on the atom directly attached to the ring (D) All meta directing groups are deactivating.

Q.20 Which ofthe following compounds can be classified as aromatic? (A) 1,2,3-Triphenylcyclopropenium cation (B) Cyclooctatetraenyl dianion (C)Azulene (D) 10-A^lene

Q.21 The structure of the compound that gives a tribromo derivative on treatment with bromine water is:

C H ' CH3 SO3H C O O H

(B) [o1 ( C ) ( 0 ) (D) [oT O H

OH

Q.22 Amongst the following, the moderately activating group is (A)NHR (B)--NHC0CH3 (C)NR2 (D)CH3

Q.23 False statement is / are : (A) Although benzene contains three double bonds, normally it does not undergo addition reaction. (B) m-chlorobromobenzene is an isomer of m-bromochlorobenzene. (C) In benzene, carbon uses all the three porbitals for hybridization. (D) An electron donating substituted in benzene orients the incoming electrophilic group to the meta position.

? Q.24 Of the species PhSH, PhSR, PhSR and Ph - S - OR the meta-substituted product is obtained from H A I

y ? (A)PhSR (B) PhSR (C) PhSR (D) P h - S - O R

II H II 0 0 o


Q.25 Match the column: Column A

CH,

(A) F O I + C R 0 3 I N C H 3 C 0 0 H

(B) + Ph,C >?

7> v (C) [ O I + n-Pr Br + ZndL > ?

CH3

Q.26 Match the following: Column I

(A) C0 2 t is evolved from

NaHC03 by the reaction of

Column B

(P) Tropylium ion

(Q) Benzaldehyde

(R) Two types of products

(S) Cumene

Column II O-H

CP). O

(B) Libermann nitroso test is given by (Q)

OH

NO2

H-N-ME

(C) Compounds gives yellow oily (R)

liquid on reaction with NaN02 + HCl

(D) Compounds evolve a colourless gas (S) N(^O^)

on reaction with active metals


I


(A) Compounds which on reaction

with neutral FeCl3 gives violet / Blue colour are

(B) Compounds which on reaction

with Na03S-^Q^)N2C1

gives para red dye.

TMoTS] _

Column II o o

n>\ 11 11 (P) PhC^TT ^C-

(Q)

(C) Compounds which do not give

yellow ppt. On reaction with NaOI

(R) P h - C H 2 - C - C H 2 C H 3

(D) Compound which have maximum % (S) q

of enol form


(A) Compounds which gives Diels

Elder's reaction in greater extent withdienophile

(B) Compounds which undergoes

ArSN reaction are

(C) Compound which has highest

aromatic characters

(D) Strongest Base

(P)

Column II

0

(Q) O

o

..(S) 0

to Bansal Classes Aromatic Compounds Page #14

EXERCISE-III

Q. 1 Write the principal organic product in each of the following reactions: CI

f^YN2 NO (i) L j l +C6H5CH2SK > A (ii) HzNNH2 > B

| triethylene CH, T G'YCOL

N0 2 CF, CI NH2

(i)HN03.H2S04 ) D (iv) r^yS (l)NaN0 '^HBr > E V (ii)NaOCH3 ,CH3OH (ii)CuBr

CI

(y) r \ / OCH3 (i)NBS,Benzoyl peroxide,CC14,heat ^ p V 3 (ii)NaSCH,

CH,

JLNO2 CI (vi) L j i +CH3CH2ONa > G (vii) f | T N 0 2 + C6H5CH2SNa >H

N02 NO2

O n - ^ 1 ^ heat

Q. 2 Write the most stable resonance structure for the cyclohexadienyl anion formed by reaction of methoxide ion with o-fluoronitrobenzene.

Q.3 Reaction of 1,2,3-tribrom-5-nitrobenzene with sodium ethoxide in ethanol gave a single product, C8H?Br2N03, in quantitative yield. Suggest a reasonable structure for this compound.

Q.4 Offer an explanation for the observation that 4-chloropyridine is more reaction toward nucleophiles than 3-chloropyridine.

Q.5 2-Bromo-1,3 -dimethylbenzene is inert to nucleophilic aromatic substitution on treatment with sodium amide in liquid ammonia. It is recovered unchanged even after extended contact with the reagent. Suggest an explanation for this lack of reactivity.

Q. 6 Two isomeric phenols are obtained in comparable amounts on hydrolysis of p-iodotoluene with 1 M sodium hydroxide at 300C. Suggest reasonable structures for these two products.

Q. 7 Given the structure of the cycloaddition product formed when benzyne is generated in the presence of furan.

^Bansal Classes Aromatic Compounds Page #15

Q.8 In each of the following reactions, an amine or a lithium amide derivative reacts with an aryl halide. Give the structure of the expected product and specify the mechanism by which it is formed.

Br Br X t j o B r

N2 H X H Q.9 1,2,3,4,5-Pentalfluoro-6-nitrobenzene reacts readily with sodium methoxide in methanol at room

temperature to yield two major products, each having the molecular formula C7H3F4N03. Suggest reasonable structures for these two compounds.

Q.10 Suggest a reasonable mechanism for each of the following reactions:

(a) C.H.Br + CH7(COOCHXH3)7 (i)ExcessNaNH2>NH2 > CfiH5CH(COOCH2CH3)2 6 3 L 1 ^ Z (ii)H20

aCH2CH,CH,GH2COCH2CH3 (i)ExcessNaNH2,NH3 > ^ T r (ii)H20 ^ "

C 1 COOCH2CH3 CH3 CH3 NCH2CH2NHCH3 NaNH2 f ^ j ^

( c ) L j J ether ^

CI CH3

F F FxJ^OCH2CH2OH F

(d) T i] w > T iT J

heat F F

tfe Bansal Classes Aromatic Compounds Page #16

EXERCISE - IV(A)

Q.l The cWorination of toluene in presence of ferric cUoride gives predominatly: [JEE 1986] (A) Benzyl chloride (B) m-chlorotoluene (C) Benzal chloride (D)o-andp-chlorotoluene

Q. 2 Aiyl halides are less reactive towards nucleophilic substitution reaction as compared to alkyl halide due to (A) The formation of less stable carbonium ion (B) Resonance stabilization (C) Longer carbon-halogen bond (D) The inductive effect [JEE 1990]

Q.3 The most basic compound among the following is: [JEE 1990] (A)Benzylamine (B) Aniline (C)Aeetaniline (D) p-nitro aniline

Q.4 Chlorination of toluene in the presence of light and heat followed by treatment with aqueous NaOH gives: (A)o-cresol (B)p-cresol (C) 2,4-dihydroxytoluene (D) Benzoic acid [JEE 1990]

Q.5 When nitrobenzene is treated with Br2 in presence of FeBr3 the major product formed is m-bromonitrobenzene. Statements which are related obtain the m-isomer are: [JEE 1992] (A) The electron density on meta carbon is more than on ortho and para position. (B) The intermediate carbonium ion formed after initial attack of Br+ attack the meta position is least

destabilized. (C) Loss of aromaticity when Br+ attacks at the ortho and para positions and not at meta position (D) Easier loss of H+ to region aromaticity form the meta position than from ortho and para position.

Q.6 Choose the correct statement from the ones given below for two aniline in: [JEE 1993]

+NH3 NH3

(I) (II) (A) II is not an acceptable canonical structure because carbonium ions are less stable than ammonium

ions . (B) II is not an acceptable canonical structure because it is non aromatic (C) II is not an acceptable canonical structure because the nitrogen has 10 valence electrons (D) II is an acceptable canonical structure

Q.7 Most stable carbonium ion is: [JEE 1995] ( A ) p - N 0 2 - C 6 H 4 - + C H 2 (B)C6H5+CH2 (C) p - CI - C6H4- +CH2 ( D ) p - C H 3 0 - C 6 H 4 -+CH 2

Q. 8 Arrange in order of decreasing trend towards SE reactions: [JEE 1995] (I) Chlorobenzene (II) Benzene (IH) Anilinium chloride (IV) Toluene (A) II > I > III > IV (B) III > I > II > IV (C) IV > II > I > III . (D) I > II > III > IV

Q.9 Among the following statements on the nitration of aromatic compounds, the false one is: [JEE 1997] (A) The rate of benzene is almost the same as that of hexadeuterobenzene (B) The rate of nitration of toluene is greater than that of benzene. (C) The rate of nitration of benzene is greater than that of hexadeuterobenzene (D) Nitration is an electrophilic substitution reaction

Q.10 Nitrobenzene can be prepared from benzene by using a mixture of conc. HN03 and conc. H2S04. In the nitrating mixture HN03 acts as a: [JEE 1997] (A) Base (B)Acid . (C) Reducing agent (D) Catalyst

Q.ll Benzyl chloride (C6H5CH2C1) can be prepared from toluene by chlorination with: [JEE 1998] (A)S02Cl2hv (B)SOCl2 (C)Cl2hv (D)NaOCl


Q.12 The most unlikely representation of resonance structure of p-nitrophenoxide ion is: [JEE 1998]

w V / 0 - w (A)

\ 5 /

O" O O" o Q.13 A solution of (+) -2-chloro-2-phenylethane in toluene racemises slowly n the presence of small amount

of SbCl5, due to the formation of: [JEE 1999] (A) Carbanion (B)Carbene (C) Free-radical (D) Carbocation

Q.14 Toluene, when treated with Br2/Fe,. gives p-bromotoluene as the major product, because the CH3 group: (A) is para directing (B) is meta directing [JEE 1999] (C) activates the ring by hyperc

Bansal Classes Organic Chemistry Study Material for IIT JEE (1)

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