Practice on Hydrocarbon

Start practice on hydrocarbon

1. Alkane

1. Which give CH4 when treated with water

1. Aluminium carbide
2. Calcium carbide
3. Silicon carbide
4. Iron carbide

     

ans : a

2. A reaction between methyl magnesium bromide and ethyl alcohol gives

1. Butane
2. Ethane
3. Propane
4. Methane

     

ans : d

3. Which of the following is a gem-dihalide ?

     

ans : a

4. Which of the following compounds will form a hydrocarbon on reaction with Grignard's reagent

     

ans : c

5. Iodoethane react with sodium in the presence of dry ether the product is

1. Pentane
2. Butane
3. Butene
4. Propane

     

ans : b

6. Which of the following has maximum boiling point ?

1. n-octane
2. iso-octane
3. 2,2,3,3-tetramethyl butane
4. n-butane

     

ans : a

7. Which of the following alkanes can be synthesized by the Wurtz reaction in good yield ?

     

ans : b

8. Arrange the following compounds in increasing order of heat evolved when one mole of each of them is hydrogenated using Pt-catalyst.

1.  I < II < III < IV
2. III < I < II < IV
3. IV < II < III < I
4. IV < I < II  III

     

ans : d

9. Which of the following cannot be formed as single major product by wurtz's coupling reaction of an alkyl halide ?

     

ans : b

10. The compound given below is chiral. What would be the outcome  of catalytic hydrogenation of a pure enantiomer of this compound

1. A pair of enantiomers in euqal would be produced
2. A pair of diastereomers in unequal amount would be produced 
3. both (a) and (b)
4. none of these

     

ans : b

11. C6H12 (x) has only two types of alkenes that can be reduced to only one type of alkane C6H14 (y) . y is ?

     

ans : b

12. To prepare a pure sample of n- hexane using sodium metal as one reactant, the other reactant will be.

1. Ethyl chloride and n-butyl chloride
2. Ethyl bromide and n-butyl bromide
3. n-propyl bromide
4. None of these

     

ans : c

13.  Which of the following is oxidized by KMnO4

1. Methane 
2. Isobutane
3. Pentane
4. Neopentane

     

ans : b

14. Which of the following is not an endothermic reaction ?

1. Combustion of propane
2. Ethane to ethene
3. Dehydrogenation
4. Change of chlorine molucule into chlorine atoms.

     

ans : a

15. Photochemical chlorination of alkane is initiated by a process of

1. RCHO 
2. CO2
3. RCOOH
4. RCOOOH

     

ans : b

16. Aromatization of n-heptane by passing over (Al2O3+Cr2O3) catalyst at 773 k gives

1. Benzene
2. Mixture of both
3. Toluene
4. none of these

     

ans : c

17. Normal butane is converted into isobutane by

1. LiAlH4
2. Zn/Hcl
3. NaBH4
4. AlCl3

     

ans : d

18. In which case the reaction is most exothermic with H2/Ni

     

ans : b

19. How many dichlorocyclohexane would be produced upon free radical chlorination of chlorocyclohexane ?

1. 4
2. 6
3. 9
4. 8

     

ans : c

20. For the given reaction how many products are optically active (all isomers)

1. 1
2. 2
3. 4
4. 3

     

ans : c

2. Alkene

1. How many different alkenes are formed when 2-chlorobutane is treated with ethanoic solution of KOH ?

1. 1
2. 2
3. 3
4. 4

     

ans : c

2. Sodium ethoxide is a specific reagent for

1. Dehydration
2. Dehydrogenation
3. Dehalogenation
4. Dehydrohalogenation

     

ans : d

3. Ethyl bromid gives ethylene when reacted with

1. Ethyl alcohol
2. Alcoholic KOH
3. Aqueous KOH
4. Dilute H2SO4

     

ans : b

4.  The compound B formed in the following sequence of reaction is .

1. Propyne
2. Propanol
3. Propene
4. Propane

     

ans : c

5. During debromination of meso-dibromobutane, the major compound formed is

1. n-butane
2. 1-butane
3. trans-2-butene
4. cis-2-butene

     

ans : c

6. The reaction

is example of

1. Sulphonation
2. Alkylation
3. Dehydration
4. Decomposition

     

ans : c

7. 1,2-dibromoethane when heated with alcoholic potash gives

1. Ethane
2. Ethylene
3. Acetylene
4. Methane

     

ans : c

8. When two alkenes may be formed by dehydrohalogenation of an alkyl halide, the alkene which is more substituted is the major or preferred product. This generalisation is Known as

1. Markownikoff's rule
2. Anti-Markownikoff's rule
3. Saytzeff rule
4. None of these 

     

ans : c

9. what is the major dehydration product in the following reaction ?

     

ans : d

10.  find wrong option for stability

1. 2,3-Dimethylbut-2-ene > 2-Methylpent-2-ene
2. trans-Hex-3-ene > cis-Hex-3-ene
3. Cis-Hex-3-ene > Hex-1-ene
4. trans-Hex-2-ene > 2-Methylpent-2-ene

     

ans : d

11. In which of the following reactions ,only single isomer of alkene is formed ?

     

ans : a

12.  Which one of the following compounds does not form an ozonide ?

1. Propane
2. Propyne
3. Propene
4. Ethene

     

ans : a

13. In a reaction

where M=molecule, R=reagent, M and R are

   

ans : d

14. Which reactions are most common in alkenes ?

1. Electrophilic addition reactions
2. Nucleophilic substitution reactions
3. Electrophilic substitution reactions
4. Nucleophilic addition reactions

ans : a

15. Which one of the following characteristics apply to both ethene and ethyne

1. Explode when mixed with chlorine
2. From white precipiate with silver nitrate solution
3. Rapidly absorbed by cold conc H2SO4
4. Declorize Baeyer's reagent giving brown precipitate

     

ans : d

16. The compound most likely to decolorize a solution of potassium permanganate is

     

ans : a

17. Ozonolysis of 2-methyl butane-2 yields

1. Both aldehyde and ketone
2. Only ketone
3. Only aldehyde
4. None of these

     

ans : a

18. Propylene on hydrolysis with sulphuric acid forms

1. n-propyl alcohol
2. Ethyl alcohol
3. Isopropyl alcohol
4. Butyl alcohol

     

ans : c

19. An alkene , on ozonolysis, gives formaldehyde and acetaldehyde. the alkene is :

1. Ethene
2. Butene
3. Butene-1
4. Propene

     

ans : d

20. Position of double bond in an organic compound is determined by

1. Oxidation 
2. Ozonolysis
3. Reduction
4. Hydrogenation

     

ans : b

21. Addition of HI on the double bond of propene yields isopropyl iodide and not n-propyl iodide as the major product. This is because the addition proceeds through

1.  A more stable free radical
2.  A more stable carbanion
3. A more stable carbonium ion
4. None of these 

     

ans : c

22. The only alcohol that can be prepared by the indirect hydration of alkene is

1. Isobutyl alcohol
2. Propyl alcohol
3. Ethyl alcohol
4. Methyl alcohol

     

ans : c

3. Alkyne

1. How many isomers exist with the formula C4H6 ?

1. 2
2. 3
3. 4
4. 9

     

ans : d

2. The shortest -C-H bond is present among the following in

1. C2H6
2. C2H4
3. C2H2
4. Same length

     

ans : c

3. Which of the folllowing molecule is totally linear

1. ethane
2. Ethylene
3. Benzene
4. Acetylene

     

ans : d

4. When chloroform is heated with Ag. the compound formed is

1. Ethane
2. Methane
3. Ethylene
4. Acetylene

     

ans : d

5. The reagents required to convert acetylene into ethylene is

1. Na, NH3
2. H2, Pd, BaSO4 quinoline
3. H2/Ni
4. Na , C2H5OH

     

ans : b

6. The reagent which convert but-1-yne into but-2-yne is

1. Na , NH3Cl
2. NaNH2 , NH3
3.  alcoholic KOH
4. NaOH

     

ans : c

7. The reagent which convert but-2-yne into but-1-yne is

1. Alc KOH
2. NaOH
3. NaNH2
4. a or c

     

ans : c

8. Acetylene can be obtained by the reaction

     

ans : a

9. The correct increasing order of heat evolved when 1.0 mole of each of the following is hydrogenated completely is

1. II < I < IV < III
2. III < IV < I < II
3. I < II < IV < III
4. None of these

     

ans : a

10. What is the major product formed in the reaction below ?

     

ans : d

11. What is formed in the reaction below as major product ?

     

ans : c

12. But-2-yne is treated with Na, liquid Nh3 , The product is 

1. Butane
2. Cis but-2-ene
3. Trans but-2-ene
4. A mixture of both cis and trans but-2-enes

     

ans : c

13.

Identify product X:

     

ans : b

14. The major product in the reaction

product is;

     

ans : b

15. 

'Y' is 

     

ans : c

16. In which of the following ,the bond length between carbon and carbon atom is equal 

1. 2-butene
2. 1-butene
3. Benzene
4. 1-propyne

     

ans : c

17. When propyne reacts with aqueous H2SO4 in the presence of HgSO4, the major product is

1. Propanal
2. Acetone
3. Propyl hydrogen sulphate
4. None of these

     

ans : b