Hydrocarbon – Alkene - AtoZ CHEMISTRY

AtoZ CHEMISTRY Hydrocarbon – Alkene

Rishi Sir [B.Tech. IIT Kanpur] www.atozchemistry.com

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Hydrocarbon – Alkene 5. Preparation of Alkene – Part 1

Q 1. In the reaction

3 2 2 2CH CH CH CH OH− − − −

Conc. H SO2 4⎯⎯⎯⎯⎯⎯→ Major product, is

(A) 3 2 2CH CH CH CH− − =

(B) 3 3CH CH CH CH− = −

(C)

(D) 3 2 2 3CH CH CH CH


Major product, is

(A) (B)

(C) (D)

Q 3. Hydrolysis of Alcohol produces ether

(A) by intermolecular dehydration

(B) At low temperature

(C) At high concentration of dehydrating agent

(D) All of these


Major product is

(A)

(B)

(C)

(D) None of these


Major product, is

(A) (B)

(C) (D) None of these


Conc.H SO2 4⎯⎯⎯⎯⎯⎯→ Major product ,

is

(A) (B)

(C) (D)

Q 7. Which one of the reactant is best to prepare

an action of alcoholic

KOH?

(A)

(B)

(C)

(D) None of these

Q 8. The product formed in the reaction

(A) (B)

CH – C = CH3 2

CH3

CH3

OH

Conc H SO2 4

CH3 CH2

CH3 CH3

(CH ) C – C (CH )3 2 3 3

Conc. H SO2 4

(CH ) C = C (CH )3 2 3 2

(CH – C – C (CH )3 3 3

O

H C = C – C = CH2 2

CH3CH3

Ph – C – C – Me

Ph Ph

OH OH

Conc. H SO2 4

Ph – C – C – Me

O Me

PhC = C

Ph

Ph

Me

Me

CH – C – C – Ph3

O Ph

CH3

CH3

OHCH3

OH

CH3

CH3

CH3

CH3

C – CH3

CH3

O

C

CH

O

CH – CH – CH = CH3 2

CH3

CH – CH – CH – CH3 3

Br

CH3

CH – C – CH – CH3 2 3

Br

CH3

CH – CH – CH – CH Br3 2 2

CH3

BrBr Zn/

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Q 9. The product formed in the reaction

Zn /

2 2Br CH C C CH Br

− − − − ⎯⎯⎯→

(A) 2 2H C C CH= = (B) 3 3CH C C CH− −


Q 10. In the dehydration of , the products

formed are

(A) (B)

(C)

(D) All the three products are formed


Product, is

(A) (B)

(C) (D)

Q 12. product (P). P would be

(A) (B)

(C) (D)

Q 13. The acid catalyzed dehydration of the alcohol

shown below gives a major product which results

from a carbocation rearrangement. Identify this

major product

(A) (B)

(C) (D)

Q 14.

Major product is

(A) (B)

(C) (D)

Q 15. Which of the following will be the correct

product (P) for the given reaction ?

(A) (B)

Br

C C

CH2 – CH2

OH(i) H

+

(ii) –H O2





(C) (D)

Q 16.

(A) (B)

(C) (D)

6. Preparation of Alkene – Part 2

Q 1. Ease of dehydration among the following

molecules

(A) I II III (B) III II I

(C) II III I (D) I III II

Q 2. Alkene is

(A) Lewis acid (B) Lewis base

(C) Amphoteric (D) Both A & B

Q 3. Which alkene has a pleasant smell ?

(A) butylenes (B) propene

(C) Ethylene (D) decene


The reactivity order of HX is

(A) HF HCl HBr HI

(B) HI HBr HCl HF

(C) HCl HBr Hf HCl

(D) None of these

Q 5. Predict which of the following alkenes reacts the

fastest with HCl?

(A) 3 2 2 2 2CH CH CH CH CH CH=

(B) Trans - 3 2 2 3CH CH CH CHCH CH=

(C) 3 2 2 3Cis CH CH CH CHCH CH− =

(D) ( )3 2 32CH C CHCH CH=

Q 6. Which one of the following compounds is most

reactive towards addition of HBr?

(A) 2 2CH CH= (B) 3 2CH CH CH− =

(C) 3 3CH CH CH CH− = −

(D)

Q 7. The order of reactivity of the following alkenes

towards electrophilic attack is

(i) 3 2CH CH CH= (ii) 2CH CHCOOH=

(iii) 2 2CH CH= (iv)

(A) i iii iv ii (B) i iii ii iv

(C) iv i iii ii (D) i iv iii ii

Q 8. Correct order of Heat of hydrogenation

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

(C) II III IV I (D) None of these

Q 9. The maximum heat of hydrogenation of the given

compound is

(A) (B)

CH – CH – CH – OH3 2 2

I

CH – C – OH3

II

CH3

CH3

CH – CH – CH – CH3 2 3

OH

III

3 2 3 3CH CH CH HX CH CH CH− = + → − −

X





(C) (D)

Q 10. What is the major product of the following

Reaction ?

(A) (B)

(C) (D)

Q 11. The reaction of

with HBr gives

(A)

(B)

(C)

(D)

Q 12. Which of the following is the correct major

product of the given reaction?

(A)

(B)

(C)

(D) None of these

Q 13. Which of the given reaction follows the Anti –

Markownikov’s rule for finding the major

product ?

(A)

(B)

(C)

(D)

Q 14. Product

How many products will be formed in above

Reaction?

(A) 2 (B) 4 (C) 6 (D) 5

Q 15. The intermediate formed during the addition of

HCl to propene in the presence of peroxide is

(A) 3 2 2CH CH CH+

(B) 3 3CH CHCH•

(C) 3 2 2CH CH CH•

(D) 3 3CH CHCH+

Q 16. The major product in the reaction

(A) (B)

(C) (D)

CH3

CBrCl3

R O2 2

Product

Br

CH3

CCl3

Br

CH3

CCl3

CBrCl2

CH3

Cl CBrCl2

CH3

Cl





7. Properties of Alkene

Q 1. Rank the following in order of decreasing

reactivity with bromine, 2Br

(1) (2) (3)

(A) 1 2 3 (B) 2 3 1

(C) 3 1 2 (D) 3 2 1

Q 2. Give the product of the following reaction

(A)

(B) and its mirror image

(C) Both A and B are formed

(D) None of these

Q 3.

A and B would be respectively

(A)

(B)

(C)

(D)

Q 4. Identify number of chiral centers present in

product obtained by following reaction

Q 5. Which of the following alkenes gives 1-bromo-2-

methyl-2-pentanol upon reaction with Br2/H2O?

(A) ( )3 3 2CH CH CHCH CH=

(B) ( )3 2 3 2CH CH CH C CH=

(C)

(D)

Q 6.

(A) (B)

(C) (D)

Q 7. The reaction of propene with HOCl (Cl2+ H2O)

proceeds through the intermediate

(A) 3 2CH CH CH Cl+− − −

(B) ( )3 2CH CH OH CH+− −

(C) 3 2CH CHCl CH+− −

(D) 3 2CH CH CH OH+− − −

Q 8. Identify the product, P in the following reaction

3 2CH CH CH NOCl P− = + →

(A) (B)





(C) (D)

Q 9. What is (are) the major product(s) of the

following reaction ?

(A)

(B) (C)

(D) Both A and B

Q 10.

A and B are

(A)

(B)

(C)

(D)

Q 11.

(A) (B)

(C) (D)

Q 12. Draw the product of following reaction with

Stereochemistry?

(A) (B)

(C) (D)

Q 13.

(A) (B)

(C) (D)

Q 14.

(A) (B)

(C) (D)

Q 15.

H O , OH2 2

B D2 6





(A) (B)

(C) (D)

8. Reaction of Alkenes

Q 1. Which reaction proceeds by anti addition?

(A)

(B)

(C)

(D)

Q 2.

1R and 2R are

(A) Cold alkaline 4 4 2 2KMnO ,OsO / H O

(B) Cold alkaline 4 3KMnO ,HCO H

(C) Cold alkaline 4 3 3KMnO ,CH O O CH− − −

(D) 6 5 3 3C H CO H,HCO H

Q 3.

A, which is true about this reaction ?

(A) A is meso 2, 3-butan –di-ol formed by syn

addition

(B) A is meso 2,3-butan –di-ol formed by anti

addition

(C) A is a racemic mixture of d and 1,2,3-butan-

di-ol formed by anti addition

(D) A is a racemic mixture of d and I2,3- butan –

di-ol formed by syn addition

Q 4. A coldaq.

3 3 KMnO4CH C C CH B

− − ⎯⎯⎯→ ⎯⎯⎯⎯→


(A) 2 4H / Pd BaSO /− Quinoline,

( )3 3CH CH CH CH cis− = −

(B) 2 4H / Pd BaSO /− Quinoline,

( )3 3CH CH CH CH Trans− = −

(C) 3Na / liq.NH , ( )3 3CH CH CH CH cis− = −

(D) ( )3 3 3Na / liq.NH ,CH CH CH CH Trans− = −

Q 5.

A RCO H3

3 3 H O2CH C C CH B− − ⎯⎯⎯→ ⎯⎯⎯⎯→


(A) 2 4H / Pd BaSO /− Quinoline,


(B) 2 4H / Pd BaSO /− Quinoline,

( )3 3CH CH CH CH Trans− = −

(C) 3Na / liq.NH ,


(D) ( )3 3 3Na / liq.NH ,CH CH CH CH Trans− = −

Q 6.





The probable structure of ‘X’ is

(A) (B)

(C) (D)

Q 7.

Identify ‘X’

(A)

(B)

(C)

(D) Reaction will not occur


Product,

The product formed is

(A) Meso (B) d− pair

(C) single product (D) None of these


Product, is

(A)

(B)

(C)

(D) None of these


Product, is

(A)

(B)

(C)

(D) None of these


A & B are respectively

(A)

(B)

(C)

(D)

Q 12.

major product, (A) A would be

(A)

(B)

(C)

C = C CH3

CH3

H

H

+ RCO H3

CH – CH = CH3 2

RCO H3

H/H O2

18

CH – CH – CH OH3 2

OH

18


OH18


OH

CH – CH = CH3 2

RCO H3

CH O¯ Na3

+

CH – CH – CH OCH3 2 3

OH

CH – CH – CH OCH3 2 3

OCH3

CH – CH CH3 2 –OH

OCH3

CH – CH = CH3 2

Cl2

500°CA

Cl /CCl2 4B

Room temp

CH – CH – CH Cl & CH – CH – CH Cl3 3 3 2

Cl ClCl – CH – CH = CH & CH – CH – CH Cl2 2 3 2

Cl

Cl – CH – CH – CH Cl & CH – CH – CH Cl2 2 3 2

Cl Cl

CH – CH – CH Cl & Cl – CH – CH = CH3 2 2 2

Cl





(D)

Q 13. Product (A), A would not be

(A) (B)

(C) (D)

Q 14.

(A)

(B)

(C)

(D) None of these

9. Ozonolysis & Oxidation of Alkene

Q 1. Write structural formulas for the compounds

which yield the following products on reductive

ozonolysis

(a) Two moles of O=C(CH3)CH2CH3

(b) (C2H5)C=O + O=CHCH=O + O=CHCH2CH3

(c) H2C=O+O=CHCH(CH3)CH(CH3)2

(d) Two moles O=CHCH2CH=O

(e) O=CHCH2CH2CH2CH=O

Q 2. Write the structure of the substrate molecule

1.KMnO4/OH

-/

2.H+ CH3CH2COOH+CH3CH2CH2-COOH

Write the structure of C7H14

C10H161.KMnO4/OH

-

2.H+/HOOC-CH2CH2-CH2-COOH(only)

Write the structure of C H10 16

C10H161.KMnO4/OH

-

2.H+/

Write the structure of C10

O

O +HOOC-CH2-CH2-COOH

H14

C10H 1.KMnO4/OH-

2.H+/14

HOOC-CH2-CH2-CH2-C

O

-C

O

-CH2-CH2-CH2-COOH


Alkene1.O32.Zn/H2O

C

CH3 CH3

O

+CH3-CH-CHO

CH3Write the structure of Alkene

(B)

(A)

(C)

(D)

(E)

7H14C

Q 3.

C6H12( ) C6H12( )B

1.O32.Zn/H2O

1.O32.Zn/H2O

Acetone Only CH3-CH2CHO Only

Write the structure of A & B.

A

Q 4.

C H1.O32.Zn/H2O

O

O

O

+CH3C

CH3 +CH2O

O


11 16

Q 5. Alkene A

A can be

(A)

O /H O3 2CH – C – CH + CH COOH+CH – C – COOH3 3 3 3

O

O

CH – C – CH = C3

CHCH3CH3

CH3





(B)

(C) Both correct

(D) None is correct

Q 6. Ozonolysis of 3 2CH CH C CH− = = will give

(A) Only 3CH CHO

(B) Only HCHO

(C) Only 2CO

(D) Mixture of 3 2CH CHO,HCHO & CO

Q 7. O-xylene on ozonolysis will give

(A)

(B)

(C)

(D)

Q 8.

What would be A

(A) (B)


Q 9. Which of the given compound given 2CO gas

after treatment with hot, alk. 4KMnO

(A) 3 3CH CH CH CH− = −

(B) 3 3CH C C CH− −

(C)

(D)

Q 10. The treatment of

with 4KMnO / H+produces

(A) 3 3 2CH COCH CH O+

(B) 3 3 3CH COCH CH COOH+

(C) 3 2CH CHO CO+

(D) 3 3CH COCH only

Q 11. One mole of a symmetrical alkene on ozonolysis

gives two moles of an aldehyde having a

molecular mass of 44 u. The alkene is

(A) propene (B) 1-butene

(C) 2-butene (D) ethene

Q 12. Which compound would give 5-keto-2-methyl

hexanal upon ozonolysis ?

(A) (B)

(C) (D)

Q 13. Which of the following compounds on reductive

ozonolysis give ( )3 32CH CO,CHO CO CH− −

and 3CH CHO ?

(A)

(B)

(C)

CH – C – CH = HC – CH3 3

C(CH )3 2

CHO

CHO& CH – C – CHO3

O

CH – C = O3

CH – C = O3

& CH – C – CHO3

O

CH – C = O3

CH – C = O3

&CHO

CHO

CH – C = O3

CH – C = O3

, CH – C – CHO3

CHO

CHO&

O





(D)

Q 14. Baeyer’s reagent is [IIT JEE 1984]

(a) alkaline permanganate solution

(b) acidified permanganate solution

(c) neutral permanganate solution

(d) aqueous bromine solution

Q 15. An organic compound ‘A’, C8H12, on

reaction with ozone followed by Zn gave one

mole each of (CHO)2 and CH3COCH3, The

structure of ‘A’ is

10. Ozonolysis & other Reactions of Alkene

Q 1. The maximum number of isomers for an alkene

with molecular formula 4 8C H is

(A) 2 (B) 3 (C) 4 (D) 5

Q 2. Products of the following reaction,

( )(i) O3

2 3 (ii) CH S3 2

Me C CHCH= ⎯⎯⎯⎯⎯⎯→ ? are :

(A) 2 3Me CO CH CHO+

(B) 3 3CH CHO CH COOH+

(C) 2 3Me CO CH COOH+

(D) 22Me CO

Q 3. But-2-ene can be obtained by reacting

(A) 1,2-dibromopropane with zinc

(B) ethyl bromide with sodium

(C) ethylidene bromide with zinc

(D) n-butyl alcohol with alcoholic KOH

Q 4. In the following reaction,

The major product is

(A)

(B)

(C)

(D)

Q 5. Ozonolysis of an organic compound gives

formaldehyde as one of the products. This

confirms the presence of

(A) a vinyl group

(B) two ethylenic double bonds

(C) an isopropyl group

(D) an acetylenic triple bond

Q 6. Identify (B) and (D) in the following sequence of

reactions

( )conc. H SO H O2 4 2

2 2H C CH A (B)

= ⎯⎯⎯⎯⎯⎯→ ⎯⎯⎯→

( )( )DPBr3

2 2(B) C H C CH⎯⎯⎯→ ⎯⎯⎯→ =

(A) 3CH OH and 2 5C H Br

(B) 2 5 4C H HSO and alc. KOH

(C) 2 5C H OH and alc. KOH





(D) 2 5 4C H HSO and aq. KOH

Q 7. The olefin which on ozonolysis gives

3 2CH CH CHO and 3CH CHO is

(A) 1-butene (B) 2-butene

(C) 1-pentene (D) 2-pentene

Q 8. Anti-Markownikoff addition of HBr is not

observed is

(A) propene (B) 1-butene

(C) 2-butene (D) 2-pentene

Q 9. Ozonolysis of the following compound

gives

(A) (B)

(C) (D)

Q 10. In presence of peroxide, hydrogen chloride and

hydrogen iodide do not give anti-Markownikoff’s

addition to alkenes because

(A) both are highly ionic

(B) one is oxidizing and other is reducing

(C) one of the steps is endothermic in both cases

(D) all the steps are exothermic in both the cases

Q 11. But-1-ene may be converted to butane by a

reaction with

(A) Zn-HCl (B) Sn-HCl

(C) Zn-Hg (D) Pd/H2

Q 12. Which of the following alkenes will give an

optically active alcohol when treated with

2 2 4H O/ H SO ?

(A) 1-Butene (B) Ethene

(C) Propene (D) 2-Methylpropene

Q 13. The product of acid catalysed hydration of 2-

phenyl propene is

(A) 3-phenyl-2-propanol

(B) 1-phenyl-2-propanol

(C) 2-phenyl-2-propanol

(D) 2-phenyl-1-propanol

Q 14. Reaction of one molecule of HBr with one

molecule of 1,3-butadiene at 40°C gives

predominantly

(A) 3-bromobutene in kinetically controlled

(B) 1-bromo-2-butene in thermodynamically

Controlled conditions

(C) 3-bromobutene under thermodynamically

controlled conditions

(D) 1-bromo-2-butene in kinetically controlled

Q 15. An alkene on reductive ozonolysis gives two

molecules of ( )2 2CH CHO . The alkene is

(A) 2,4- hexadiene

(B) 1,3-cyclohexadiene

(C) 1,4-cyclohexadiene

(D) 1-methyl-1,3-cyclopentadiene

(E) 1,2-dimethyl cyclopropene

Q 16. HBr reacts with 2 3H C CH OCH= − under

anhydrous conditions at room temperature to give

(A) 3CH CHO and 3CH Br

(B) 2BrCH CHO and 3CH OH

(C) 2 2 3BrCH CH OCH− −

(D) 3 3H C CHBr OCH− −

Q 17. The products obtained by the ozonolysis of 2-

ethyl but-1-ene are

(A) ethanal and propanone

(B) ethanal and butanal

(C) ethanal and 3-pentanone

(D) methanal and 2-pentanone

(E) methanal and 3-pentanone





Answer Key


(1). B (2). C (3). D

(4). B (5). C (6). D

(7). C (8). B (9). A

(10). D (11). C (12). A

(13). A (14). B (15). C

(16). D


(1). C (2). B (3). C

(4). B (5). D (6). D

(7). C (8). C (9). A

(10). C (11). B (12). C

(13). B (14). B (15). D

(16). B

7. Properties of Alkenes

(1). A (2). B (3). C

(4). 3 (5). D (6). B

(7). A (8). B (9). B

(10). A (11). D (12). C

(13). A (14). C (15). A

(16). A

8. Reaction of Alkenes

(1). A (2). B (3). A

(4). A (5). A (6). A

(7). B (8). B (9). B

(10). A (11). B (12). A

(13). D (14). C

9. Ozonolysis & Oxidation of Alkene

(1).

(a)

(b)

(c)

(d)

(e)

(2).

(a)

(b) (c)

(d)

(e)

(3).

(a)

(b)

(4).

(5). C (6). D (7). D

(8). B (9). D (10). B

(11). C (12). B (13). B, C

(14). A (15). D

10. Ozonolysis & other Reactions of Alkene

(1). C (2). A (3). C

(4). B (5). A (6). C

(7). D (8). C (9). B

(10). C (11). D (12). A

(13). C (14). B (15). C

(16). D (17). C

C = CCH – CH2 3

CH3CH3

CH – CH3 2

C = CH – CH = CH – CH CH2 3

C H2 5

C H2 5

H C = CH – CH – CH 2

CH3

CH3CH3

CH = CHCH2

CH = CHCH2

CH – CH – CH = CH – CH – CH – CH3 2 2 2 3

C = CH – CH3

CH3

CH3

C = C CH3

CH3CH3

CH3

CH – CH – CH = CH – CH – CH3 2 2 3

H C3 CH3

CH2

CH3 CH3


Hydrocarbon – Alkene - AtoZ CHEMISTRY

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